The Physics of Boat Ramps
ref
pound fishing boat up a fairly steep concrete launch ramp. The
boat is on a 4-wheel trailer in good condition. The truck is,
of course, rear-wheel drive, and has more than enough horsepower.
Special consideration: the ramp is *wet*, due to water dripping off
other boats that were just pulled out.
My truck can just BARELY pull the boat up the ramp under these
conditions. If it's dry, no problem, but when the ramp is wet,
the tires slip and spin, sometimes even smoking. It's a very,
very marginal situation. Last night, I came very close to being
stranded at a deserted ramp after dark; I could *not* get that
boat up that ramp, and finally made it up after creeping about an
inch at a time, before the tires would slip. God only knows what
kind of wear this produced on my transmission.
Question: what kind of tire tread design would provide the *most*
friction? Knobby, off-road type, or a smoother "pavement" type?
Remember, by the way, that this is extremely low-speed operation,
just barely turning, in fact, so concepts like "hydroplaning"
probably wouldn't apply here. We're talking about pulling a load
up a wet concrete surface.
How about it, you guys? I need to buy new tires for my truck in
another couple of months, and I'd appreciate some input. In addition,
I think it'd make an interesting discussion topic, as well.
Ron Morgan
r...@bga.com
Sam
limited slip). I would put up a slippery ramp and one tire would spin
(no posi!)... I helped the situation by putting all of the crap in the
back of the truck that was in the boat, to put more weight over the
rear tires (Coolers, skis, gas cans, clothes, etc.) This made a
difference. I don't know what type of truck you have, or if it has
posi, but with my NEW '95 Dakota w/posi + 5 speed I am able to pull
that same boat, with all of the crap still in the boat, with no problem
out of the same ramp. I do run a lower tire pressure, as this tends to
put more rubber onto the ground, giving more traction. You might try
that too...(it wouldn't hurt).
BTW If you didn't already know this, when pulling out of a boat
ramp with a automatic trans, and you work pretty hard to pull that boat
up (any pull should be considered) the ramp, make sure you don't pull
up to the staging area and shut off your truck while securing you boat.
All of the heat generated by the pull will not leave the transmission
(as it didn't get cooled yet by the transmission cooler)...and can
cause a lot of wear/tear/damage to your transmission. My bone-head
friend went through 2 transmissions over 2 seasons going to the
Colorado river with his boat. Every time he got it out of the water he
would shut down, secure the boat, then take off...with an air temp of
about 110 F. that truck would almost boil the transmission fluid!!! He
learned.
I got a 5 speed ( no cooler needed!), and it works a lot better
than a automatic (at least for me it does).
My $.02
..Sam
Andrew Cooke
>Conditions: a standard half-ton truck, attempting to pull a 3,000
>pound fishing boat up a fairly steep concrete launch ramp. The
>boat is on a 4-wheel trailer in good condition. The truck is,
>of course, rear-wheel drive, and has more than enough horsepower.
>
>Special consideration: the ramp is *wet*, due to water dripping off
>other boats that were just pulled out.
have you tried deflating the rear tyres a bit? you'd get a larger
contact area.
andrew
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kevin weber
> Question: what kind of tire tread design would provide the *most*
> friction? Knobby, off-road type, or a smoother "pavement" type?
> Remember, by the way, that this is extremely low-speed operation,
> just barely turning, in fact, so concepts like "hydroplaning"
> probably wouldn't apply here. We're talking about pulling a load
> up a wet concrete surface.
>
> How about it, you guys? I need to buy new tires for my truck in
> another couple of months, and I'd appreciate some input. In addition,
> I think it'd make an interesting discussion topic, as well.
There's a lot coming into play.
I find all terrains are significantly better than road tires. I would
assume mudders are even better. My guess would be that the deep tread
actually allows some of the edges of the tread to grip the ramp, cause
there's certainly lower area in contact. Course that also means greater
psi.
Another factor is the softness of the rubber. I would suspect that given
two identical tires, the one with the lower tread life would be better.
You could also get a bit wider tires. I've also seen people with a bucket
of sand they toss out to get a better grip. No-one really complains about
sand at a launch ramp.
kevin
Joseph Siddall
>Conditions: a standard half-ton truck, attempting to pull a 3,000
>pound fishing boat up a fairly steep concrete launch ramp. >
>Special consideration: the ramp is *wet*, due to water dripping off
>other boats that were just pulled out.
>
>
>Ron Morgan
>r...@bga.com
Ron -
When you buy your tires, make sure you get a better traction rating. Talk
to the tire dealer about traction ratings and wet pavement. He may help you
out tremendously. (Softer tires may wear quicker.)
Other solutions to consider can make a big difference :
1. Put a couple hundred pounds of sand bags or blocks in the
very back of the truck. Spinning can be caused by not
enough weight on the rear wheels.
2. Adjust your boat on the trailer to increase the tongue weight
of the trailer (not to an extreme). With the boat further
on the trailer, you will get more weight on the truck tires.
3. Next truck, get limited slip differential to use both back wheels
instead of one.
Good luck and may all your ramps be dry ones,
Joe
Longrigger
I have stuck the floor mats in front of the tires once when I was alone
and got stuck, but sand would be alot better.
Longrigger
Steve Cutchen
> >Conditions: a standard half-ton truck, attempting to pull a 3,000
> >pound fishing boat up a fairly steep concrete launch ramp. >
>
> >Special consideration: the ramp is *wet*, due to water dripping off
> >other boats that were just pulled out.
Ron, Missed the original post... but here's a technique I use to get my
boat up the ramp that works pretty well. Then I'll add an emergency
method that is nice to keep in reserve.
As with you, I've found that getting a boat up a wet ramp can be no small
task. I have a 24 ft Grady White, pulled by a new (OHC 4.6L V8) Mercury
Marquis (has towing package, no "de Sade" option). I also use a GMC P/U,
2WD, also with towing option, also V8 automatic.
The idea is to kinda simulate what anti-lock brakes do to help create an
anti-slip traction control. When you get ready to pull out, keep your
foot on the brake, hard. Push on the accelerator to get the engine RPMs
up (and thus power), by spinning up the torque converter. This is kinda
like those brake starts you used to do from a traffic light with Dad's old
Galaxie 500. (Oh sure, like you never did it?!?) Now s-l-o-w-l-y lift
pressure off of the brake until the vehicle and trailer just start to
move. Then KEEP YOUR BRAKE FOOT IN THIS POSITION UNTIL YOU GET MOVING
WELL UP THE RAMP. Modulate your speed with the brake foot. Leave the
accelerator foot pretty far or all the way down. The brakes are helping
to minimize wheel spin! Taa Daa... Poor man's traction control!
YMMV, and I won't vouch for any affects on the drivetrain (geez, you're
pulling a big ol' boat anyhow, and the amount of time it takes to do this
is probably 15 seconds or so...)
An alternate, and by my vote emergency, method is to use the boat to help
get you started. This one can be a bit dicey. It can work it you sink in
your trailer enough (drive on type...). As the car starts to pull out,
put the boat in gear and gun it. As you get going, kill the boat engine
and tilt up. Obviously, timing is key here. Could bend a lower unit or
prop; could ride up on the trailer into the tow vehicle... I don't
recommend this technique except in an emergency. It beats leaving the
boat at the dock until the tide rises, or worse yet, launching the boat,
trailer and tow vehicle.... Both methods can be combined.
---Steve
--------
Steve Cutchen If we always do what we've always done,
scut...@phoenix.net we'll always get what we've always got...
Erik Vaaler
boats, ramps and tow vehicles. I have better traction on my jeep since I moved
up on tire size. The tires are all weather radials. I can still spin all 4
tires if the ramp is mucky enough. Just having new tires will make a difference
because the rubber will be softer and the thicker tread will be more compliant
than on the older tires.
My neighbor mounted a hitch ball on the front bumper of his 2WD truck which let
him keep his rear tires high and dry. This can be particularly important at low
tide, especially on ramps in estuaries that tend to silt up and/or grow moss. I
carried a 20 foot heavy duty tow rope for several years untill the size of my
tow vehicle caught up with my boat. I have also seen tongue extensions used for
the same purpose. Many sailboaters use these because a keelboat has to be sent
WAY back before it will float off the trailer. They either telescope out of the
trailer tongue or are carried along side. Some of them even have their own
wheels on them that will take much more abuse than a standard trailer jack
wheel.
My jeep has mushy rear springs and a short wheelbase, so I don't run with much
tongue weight. You can usually run much more tongue weight on a real truck like
yours. 300 or 400 lbs of tongue weight, if you are not already running that
much, could do a lot for your traction problems. Check with the truck
manufacturer to see what they recommend.
vaaler
Frank Ball
& Conditions: a standard half-ton truck, attempting to pull a 3,000
& pound fishing boat up a fairly steep concrete launch ramp. The
& boat is on a 4-wheel trailer in good condition. The truck is,
& of course, rear-wheel drive, and has more than enough horsepower.
& Special consideration: the ramp is *wet*, due to water dripping off
& other boats that were just pulled out.
& My truck can just BARELY pull the boat up the ramp under these
& conditions. If it's dry, no problem, but when the ramp is wet,
& the tires slip and spin, sometimes even smoking. It's a very,
& very marginal situation. Last night, I came very close to being
& stranded at a deserted ramp after dark; I could *not* get that
& boat up that ramp, and finally made it up after creeping about an
& inch at a time, before the tires would slip. God only knows what
& kind of wear this produced on my transmission.
You don't say what the truck is, but does it have a limited slip
differential (pozi-trac, sure-grip, etc)? If not that would get you
double the traction. They can be added to many of the trucks out there.
________________________________________________________________________
Frank Ball 1UR-M fra...@sr.hp.com (707) 794-4168 work
Hewlett Packard (707) 794-4848 fax (707) 538-3693 home
1212 Valley House Drive http://web.sr.hp.com/~frankb/
Rohnert Park CA 94928-4999 KC6WUG, AMA, DoD #7566, NMLRA, I'm the NRA.
U.S.A. Dodge V8 Dakota, Yamaha IT175 XT350 YZF600R Seca 750
George B
he one with the lower tread life would be better.
>You could also get a bit wider tires. I've also seen people with a bucket
>of sand they toss out to get a better grip.
Man, sand on concrete can REALLY cause you to slip! Sand on ICE is ok
but no sand is better on non-frozen concrete.
George Bonser
gr...@cris.com
George B
>How about it, you guys? I need to buy new tires for my truck in
>another couple of months, and I'd appreciate some input. In addition,
>I think it'd make an interesting discussion topic, as well.
>Ron Morgan
>r...@bga.com
Wide, sticky tires in my opinion. Though they spread the weight out
more, there is more surface for gripping. It will reduce fuel economy
somewhat though. Also, I would worry more about hydroplaning on FRONT
wheels where you could loose steering control.
You might try putting some weight over that axle or letting 5lb of air
out if you get stranded.
George Bonser
gr...@cris.com
Charlie and Dorothy Fly
<sid...@bnr.ca> wrote:
> r...@bga.com (ref) wrote:
> >Conditions: a standard half-ton truck, attempting to pull a 3,000
> >pound fishing boat up a fairly steep concrete launch ramp. >
>
> >Special consideration: the ramp is *wet*, due to water dripping off
> >other boats that were just pulled out.
> >
> >
> >Ron Morgan
> >r...@bga.com
>
I stuck my truck in Galveston Bay this way. My solution was to buy an old
CJ5. Now I drop into 4 wheel drive in low range. And no problem.
A cheaper alternative is to mount a trailer ball on the front which keeps
those rear wheels way up out of the water.
cfly
--
Charlie and Dorothy Fly
Non-Trivial Solutions
2951 Marina Bay Dr.
Suite 130-349
League City, TX 77573-2733
Frank R. Borger
>>
>> How about it, you guys? I need to buy new tires for my truck in
>> another couple of months, and I'd appreciate some input. In addition,
>> I think it'd make an interesting discussion topic, as well.
Er, does that imply that your current tires are rather bald?
If so, 'nuf said.
Relative weight of vehicle and tow is important. (If the wheels
on your trailer are bigger than the wheels on your tow vehicle,
you're in trouble. Saw a Chicago flatlander trying to tow a large
boat with his Beamer. Didn't make it.)
In your case, the truck should have enough towing weight, but
the question is about weight on the rear wheels.
o The angle of the ramp tends to transfer more weight to the
rear wheels.
o Tounge weight of the trailer is important.
I am hauling a smaller 14' runabout (40 horse motor) with a
Ranger pickup in a similar situation. I have no problems.
o I have a stick, so can control things better.
o When I was towing with a station wagon and automatic, I would:
o Put the transmission in second
o Step on the brake
o Give it some gas.
o Use the break as a clutch, slowly easing up so that there
was no jerk in the initial pull.
Frank R. Borger - Physicist ___ "I think medical research would show
Michael Reese - U of Chicago |___ that being a Cubs fan lengthens
Center for Radiation Therapy | |_) _ your life. Or maybe it just _seems_
net: Fr...@rover.uchicago.edu | \|_) longer. " - Mike Royko
ph: 312-791-8075 fa: 791-2517 |_)
Art L. Kotz
Huffman <dhuf...@sumter.awod.com> wrote:
> I thought friction was normal force times coefficient of
> friction. Nowhere mentioning pressure or area. Deflation is
> for soft surfaces where pressure does need to be reduced?
...
> Grasping another opportunity to be wrong!
seems you caught this opportunity nicely ;-)
That's the description you find in physics 101, but it doesn't work well
in this case. It works for flat surfaces in contact (with a few other
assumptions). When you add rough surfaces, compressible and deformable
surfaces, and weak surface features (like sand on the ramp) that can
withstand only a (smallish) maximum force before breaking away, then
surface area and tread play an important role.
Art Kotz <ko...@winternet.com>
Doug Huffman
I thought friction was normal force times coefficient of
friction. Nowhere mentioning pressure or area. Deflation is
for soft surfaces where pressure does need to be reduced?
Grasping another opportunity to be wrong!
[][][][][][][][][][][][][][][][][][][][][][][][][][][][]
Andy Dingley
>Man, sand on concrete can REALLY cause you to slip!
This isn't sand on concrete (like a building site) but sand on a
concrete boat ramp. All the ramps I've seen have been pretty slippery
with weed and green gunk.
If I used the same ramp every day, I'd scrub the thing clean and use
Jeyes fluid or caustic soda on it occasionally to keep the gunk off. I
know little about boat ramps, but I do know about silage clamps and
slurry lagoons (bleurgh !) - even for these noxious devices it's
worth doing a bit of scrubbing & hosing occasionally.
Failing that, get as big a contact patch as you can. Soft rubber in
small tread blocks (not great mud-plugger tread bars) and a low enough
pressure to let the tyre flatten as much as is practical.
--
Andy Dingley din...@codesmth.demon.co.uk
alt.flame - Making the world a safer place for postal workers.
Sam
*snip*
>> months, and I'd appreciate some input. In addition,
>>I think it'd make an interesting discussion topic, as well.
>>
>>r...@bga.com
>>
>>
>Ron,
>
>I have a Full size Dodge Van and have never had a problem pulling the
>boat up the ramp, except for one occasion. It was a really long and
very
>wet ramp. I was having problems with wheel spin, I remember reading
>somthing about turning your front tires, (somthing about changing the
>pull ratio) and also applying the parking brake a bit.
You must have a non-posi rear end on your van... The emergency
brake trick worked on my '91 Dakota when semi-stuck in sand (I had a
non-posi rearend).
>Boat pulled right out with out any wheel spin what-so-ever.
>
>Good luck.
>
>
>Michael
>
Gil Meacham
>Conditions: a standard half-ton truck, attempting to pull a 3,000
>boat is on a 4-wheel trailer in good condition. The truck is,
>
>other boats that were just pulled out.
After many years of enjoying the entertainment of watching people pull boats
out at a wide variety of ramps throughout the western US, I know this:
The initial pull to get a boat up out of the water is substantial, if you
think of how hard it is to pull a small water skier up out of the water,
imaging something with 30 times the weight and surface tension and bad
hydrodynamics (the trailer...not the boat!)
Many people think the best approach is to try to accelerate quickly to "get
the damn thing going!", so they give their rig too much throttle.
Once you break adhesion on a slick surface, you cannot pull a load equivalent
to before you spun the wheels. So if it spins, let off the throttle and let
the wheels catch traction. Then, try again with less acceleration. Don't
think that spinning your wheels faster will get you up the ramp, 'cause it
will only make it harder to get out.
As other posts have said, lowering your tire pressure a little will help a
lot. But I have found on most ramps I can get my boat out by just driving a
little more gently and not starting the spinning. I find an auto trans works
better, since you can accelerate from a standstill very slowly without having
to dump the clutch. But I have had several trucks with 4 speeds and a couple
of 5 speeds. You just gotta take it easy, and don't try to pull the boat out
fast.
Michael Gilbert
>Conditions: a standard half-ton truck, attempting to pull a 3,000
>pound fishing boat up a fairly steep concrete launch ramp. The
>boat is on a 4-wheel trailer in good condition. The truck is,
>of course, rear-wheel drive, and has more than enough horsepower.
>
>Special consideration: the ramp is *wet*, due to water dripping off
>other boats that were just pulled out.
>
>
>friction? Knobby, off-road type, or a smoother "pavement" type?
>Remember, by the way, that this is extremely low-speed operation,
>just barely turning, in fact, so concepts like "hydroplaning"
>probably wouldn't apply here. We're talking about pulling a load
>up a wet concrete surface.
>
I have a Full size Dodge Van and have never had a problem pulling the
boat up the ramp, except for one occasion. It was a really long and very
wet ramp. I was having problems with wheel spin, I remember reading
somthing about turning your front tires, (somthing about changing the
pull ratio) and also applying the parking brake a bit.
Boat pulled right out with out any wheel spin what-so-ever.
Good luck.
Michael
Terry Dobie
>Conditions: a standard half-ton truck, attempting to pull a 3,000
>pound fishing boat up a fairly steep concrete launch ramp. The
>boat is on a 4-wheel trailer in good condition. The truck is,
>of course, rear-wheel drive, and has more than enough horsepower.
. . . .
>Ron Morgan
>r...@bga.com
Since you have more than enough horsepower - if one rear wheel starts
to spin, hold the parking brake release open and apply the parking
brake. If you apply hard enough, both wheels will receive power. You
can also try stabbing at the parking brake if the engine does not have
enough power.
Not a sure fire thing. But it is another trick to but in your bag.
Terry Dobie
83 CJ7
Hailey, ID
David Perry
that you have to ease into the pull. I use an awefull ramp in East
Falmouth Cape Cod that is always covered in a thin layer of scum. On
one occasion, I was sort of hurried by other boaters waiting to get out
of the water and I pulled to fast. Before I knew it, my tires were
spinning and I was moving backward. OOOOPS! Thank god I stopped on
time.
I now make sure that my air pressure is a little lower (more surface
space), and that I ease into the pull. At this one particular ramp, I
often throw handfulls of sand onto the algae to create a little
traction. I read a lot of others posts where sand is the enemy, but in
this scenerio, it works well.
Good luck
David
wa...@onramp.net
To get the best traction on a wet surface (a boat ramp) look for an all
season tire with a high volume of tread surfaces. This type of tire will
have a lot of tiny cuts in the tread design. When the tire is stressed
pulling a load, this type of tread will flex and the edges of these cuts
will grip the road surface. Do Not consider the course off road tread
design! It has the worst hard surface traction.
You should also be very light on the gas pedal. A posi traction
differential is also a big help if it is kept maintained and the clutches
adjusted.
Would you believe I pull a 3800 lb boat up steep boat ramps with a chev
s-10 with no problems?
Good Luck
Wayne
wa...@onramp.net
Sam
>
>The next time this happens, try letting some air out of the rear tires
- enough
>to increase the footprint somewhat. Be sure to air up again at the
>first opportunity.
>
>In article <4b4p6j$k...@newsbf02.news.aol.com>, longr...@aol.com
No, really... Tire pressure helps a ton, and the start of the pull
is the most important part. Once underway, roll into the throttle, but
maintain traction... (I think that all of the answers I have read here
would help.)
...Sam
Randy Burleson
> another couple of months, and I'd appreciate some input. In addition,
> I think it'd make an interesting discussion topic, as well.
>
Well, either way, new tires will likely help. For my boat, I use AT
(All Terrain) tires with an agressive, knobby tread. Airing down can
help the tire conform even better to the surface. If you really get
stuck, unhitch the boat and try getting a lead with your safety chains
or some other extension (not good for the trailer ball receptacle,
but better than sleeping the night). A bag of sand costs 5 bucks from
any place that supplies sandblasting abrasives -- cheap insurance.
Randii
Steve Das
believe is one of the required ratings on all DOT tires. Check with your
tire dealer and compare ratings. Go for the tire with the best rating
that will meet the rest of the requirements for your truck such as load
rating and speed. You will be surprised when you start looking into the
ratings. Assuming you are talking about the typical concrete ramp, all
you are really looking for is wet weather traction.
Hope this helps,
Steve
Jerry Steele
>From: r...@bga.com (ref)
>Subject: The Physics of Boat Ramps
>Date: 18 Dec 1995 10:01:23 -0600
>Conditions: a standard half-ton truck, attempting to pull a 3,000
>pound fishing boat up a fairly steep concrete launch ramp. The
>boat is on a 4-wheel trailer in good condition. The truck is,
>of course, rear-wheel drive, and has more than enough horsepower.
>Special consideration: the ramp is *wet*, due to water dripping off
>other boats that were just pulled out.
>My truck can just BARELY pull the boat up the ramp under these
>conditions. If it's dry, no problem, but when the ramp is wet,
>the tires slip and spin, sometimes even smoking. It's a very,
>very marginal situation. Last night, I came very close to being
>stranded at a deserted ramp after dark; I could *not* get that
>boat up that ramp, and finally made it up after creeping about an
>inch at a time, before the tires would slip. God only knows what
>kind of wear this produced on my transmission.
>Question: what kind of tire tread design would provide the *most*
>friction? Knobby, off-road type, or a smoother "pavement" type?
>Remember, by the way, that this is extremely low-speed operation,
>just barely turning, in fact, so concepts like "hydroplaning"
>probably wouldn't apply here. We're talking about pulling a load
>up a wet concrete surface.
>How about it, you guys? I need to buy new tires for my truck in
>another couple of months, and I'd appreciate some input. In addition,
>I think it'd make an interesting discussion topic, as well.
>Ron Morgan
>r...@bga.com
Get in the boat, start it up, and use it to push the truck up.
Now, let's see who takes me seriously.
Russ Poffenberger
: Conditions: a standard half-ton truck, attempting to pull a 3,000
: pound fishing boat up a fairly steep concrete launch ramp. The
: boat is on a 4-wheel trailer in good condition. The truck is,
: of course, rear-wheel drive, and has more than enough horsepower.
: Special consideration: the ramp is *wet*, due to water dripping off
: other boats that were just pulled out.
: My truck can just BARELY pull the boat up the ramp under these
: conditions. If it's dry, no problem, but when the ramp is wet,
: the tires slip and spin, sometimes even smoking. It's a very,
: very marginal situation. Last night, I came very close to being
: stranded at a deserted ramp after dark; I could *not* get that
: boat up that ramp, and finally made it up after creeping about an
: inch at a time, before the tires would slip. God only knows what
: kind of wear this produced on my transmission.
I know this doesn't really help you, but I find that 4 wheel drive low is
excellent for pulling up a ramp. My '88 Cherokee with 4.0L engine can pull
my boat out at idle (albeit slow!).
Russ Poffenberger DOMAIN: pof...@San-Jose.ate.slb.com
Schlumberger Technologies ATE UUCP: {uunet,decwrl,amdahl}!sjsca4!poffen
1601 Technology Drive CIS: 72401,276
San Jose, Ca. 95110 Voice: (408)437-5254 FAX: (408)437-5246
2-Thorny
:
: An alternate, and by my vote emergency, method is to use the boat to help
: get you started. This one can be a bit dicey. It can work it you sink in
: your trailer enough (drive on type...). As the car starts to pull out,
: put the boat in gear and gun it. As you get going, kill the boat engine
: and tilt up. Obviously, timing is key here. Could bend a lower unit or
: prop; could ride up on the trailer into the tow vehicle... I don't
: recommend this technique except in an emergency. It beats leaving the
: boat at the dock until the tide rises, or worse yet, launching the boat,
: trailer and tow vehicle.... Both methods can be combined.
We use this method all the time for the last 10 years, haven't had any
problems. We trailer a 254 Mako on a Float On brand trailer. The person
gunning the boat has to know what he is doing, the one driving the truck
needs to pull out slowly. We also used this technique to pull out a 23 foot
cruiser with a 4 cylinder rear-drive Nissan pick-up. :)
--
*
/ \
*Thorny *
\ /
*
"Work for a living. Play for a life."
Southern Comfort
Paul J Kristof
winch on the vehicle (front or back) was used to pull the boat and trailer
up the ramp to a more level location and then it was attached to the vehicle.
The boat trailer had an adjustable wheel near the hitch. Some people used
electical winches with a long remote control. This is a bit more expensive
but if you boat a lot it might be easier on you and your truck.
Paulkr
Ed Porter
Keith Boyd
>==========ref, 12/18/95==========
>
>Conditions: a standard half-ton truck, attempting to pull a 3,000
>pound fishing boat up a fairly steep concrete launch ramp. The
>boat is on a 4-wheel trailer in good condition. The truck is,
>of course, rear-wheel drive, and has more than enough horsepower.
>
>Special consideration: the ramp is *wet*, due to water dripping off
>other boats that were just pulled out.
>
>My truck can just BARELY pull the boat up the ramp under these
>conditions. If it's dry, no problem, but when the ramp is wet,
>the tires slip and spin, sometimes even smoking. It's a very,
>very marginal situation. Last night, I came very close to being
>stranded at a deserted ramp after dark; I could *not* get that
>boat up that ramp, and finally made it up after creeping about an
>inch at a time, before the tires would slip. God only knows what
>kind of wear this produced on my transmission.
>
>friction? Knobby, off-road type, or a smoother "pavement" type?
>Remember, by the way, that this is extremely low-speed operation,
>just barely turning, in fact, so concepts like "hydroplaning"
>probably wouldn't apply here. We're talking about pulling a load
>up a wet concrete surface.
>
>How about it, you guys? I need to buy new tires for my truck in
>another couple of months, and I'd appreciate some input. In addition,
>I think it'd make an interesting discussion topic, as well.
>
>Ron Morgan
>r...@bga.com
>
>
If the ramp is real smooth concrete, then an all terrain tread pattern should
work good. If the ramp is made of rough concrete with lots of filler
material like rocks and pebbles, then you may want to go with a more
aggressive knobby or mud tread tire. Then you have to ask yourself if
you want to put up with more tire noise/tire wear just for this situation.
However, it may be that tires alone won't solve your problem. If you are
slipping and spinning a lot, you may want to consider having a posi-traction
rear end installed. (If your vehicle already has one installed, get it
checked out!) One other thing that might help is more weight on the bed of
the truck. You might can adjust your boat to put more tongue weight on the
rear of the truck which might give you a good bit more traction. If all of
this fails get rid of your truck and go buy a 4x4, or else get a lighter
boat!!!
Keith
PS- I have seen small "tracks" that are made to help get vehicles through poor
traction conditions (like snow or ice) for a short distance. They
look like tank treads and are placed in front of the driven tires. Most of
them come in different lengths and are available from most of the 4x4
mail order catalogs. That might be something to consider!
Keith Boyd | Nothing could be finer than huntin' and
3325 Platt Springs Rd | fishin' in South Carolina - Me -
West Cola, SC 29170 | Go Gamecocks!! | Go Panthers!!
keith....@columbiasc.ATT.GIS.COM | Go Braves!!
VP: 1-632-6419 Ma Bell: 1-803-939-6419 Fax: 1-803-739-7317
Steve Cutchen
---begin repost---
The idea is to kinda simulate what anti-lock brakes do to help create an
anti-slip traction control. When you get ready to pull out, keep your
foot on the brake, hard. Push on the accelerator to get the engine RPMs
up (and thus power), by spinning up the torque converter. This is kinda
like those brake starts you used to do from a traffic light with Dad's old
Galaxie 500. (Oh sure, like you never did it?!?) Now s-l-o-w-l-y lift
pressure off of the brake until the vehicle and trailer just start to
move. Then KEEP YOUR BRAKE FOOT IN THIS POSITION UNTIL YOU GET MOVING
WELL UP THE RAMP. Modulate your speed with the brake foot. Leave the
accelerator foot pretty far or all the way down. The brakes are helping
to minimize wheel spin! Taa Daa... Poor man's traction control!
---end repost---
But my brother, cutc...@infomail.infonet.com, reminded me that there is
still another method:
---
YOU FORGOT THE OTHER METHOD...
RUN AROUND THE BOAT RAMP CUSSING AND SWEARING...
BLAME THE ENTIRE MESS ON EITHER YOUR FATHER OR BROTHER...
FOUL A STERN LINE ON THE TRAILER AND RIP OFF A BRAKE LIGHT...
REPEAT LINES 1 and 2
CUSS FATHER UNDER BREATH FOR BEING TOO CHEAP TO BUY/LEASE FORD 4-WHEEL DRIVE
TURBO DIESAL...
TRY TO SIMULATE TRACTION CONTROL, WHILE PUSHING WITH BOAT, WHILE HAVING FAT
MAN (OR SEVERAL BOYS) JUMP UP AND DOWN IN THE TAIL GATE OF TRUCK.
---
Then of course, there are other things to do once the boat's out:
---
BOAT REMOVAL FOLLOW UP PROCEDURES:
KNOW SOMEONE WHO DOES NICE FIBERGLASS WORK FOR NOT A LOT OF MONEY.
(NEED TO FIX FRONT OF BOAT BEFORE NEXT TRIP)
FIX TRAILER BRAKE LIGHT
FIX TRAILER WHEEL BEARING COVER
FIX TRAILER
FIX ENGINE SPEEDOMETER OPENING
FIX LIVE BAIT WELL
FIX POWER STEERING (SIMULATED HYDROLIC POWER STEERING)
FIX ELCTRONICS
DRAIN SALT WATER FROM FUEL TANKS
BUY $200 WORTH OF FUEL (BOAT ONLY)
BUY $ 35 WORTH OF FUEL (CAR ONLY)
REPLACE $75 WORTH OF BEER CONSUMED ON TRIP
REPLACE $ .50 WORTH OF FOOD CONSUMED ON TRIP
REPLACE $35 WORTH OF TACKLE LOST/USED ON TRIP
WASH DOWN BOAT
WASH DOWN TRAILER
DRY BOAT
WAX BOAT
LUBRICATE BOAT, TRAILER, ENGINE
PAY STORAGE FEE
PURCHASE EXPENSIVE STATE OF THE ART FISHING TACKLE
(SPECIALY DESIGNED TO CATCH FISHERMERN)
REMIND SELF THAT THIS IS FUN,
AND
DO IT ALL AGAIN THE NEXT TIME THE GULF OF MEXICO IS WEATHER PERMITTING...
REMEMBERING TO RELEASE THE FISH TO KEEP THE ECO-NAZIS HAPPY.
---
---Steve
--------
Steve Cutchen If we always do what we've always done,
scut...@phoenix.net we'll always get what we've always got...
Tom Cook
offers on the items below please fill out this sheet and
then EMAIL IT BACK TO "TO...@IX.NETCOM.COM".
- Trucks - Hunting - Fishing - Auto Racing - GOOD FOOD -
_________________________________________________________
NAME:
ADDRESS:
CITY:
STATE:
ZIP:
PHONE:
AGE:
(opional)
INCOME:
_________________________________________________________
Thank you
SmoothG
>
>jst...@azstarnet.com (Jerry Steele) wrote:
>
>>In article <4b438j$2...@urchin.bga.com> r...@bga.com (ref) writes:
>>>From: r...@bga.com (ref)
>>>Subject: The Physics of Boat Ramps
>>>Date: 18 Dec 1995 10:01:23 -0600
>
>Put a shit load of weight in the bed of the truck. This will help you
get more traction. As far as tires go, try to get a soft compound
tire. They will wear faster, but give more traction.
The Electrical Engineering Mack Daddy
SmoothG
Zilbandy
>>Ron Morgan
>>r...@bga.com
>Get in the boat, start it up, and use it to push the truck up.
>Now, let's see who takes me seriously.
I suppose if you had a big enough prop, that would work. That's how
airplanes used to do it.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Barry Burnett (Zilbandy)
Tucson, Arizona USA
z...@azstarnet.com
Windows 95!... from the same people who brought you EDLIN!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jerry Steele
>From: z...@azstarnet.com (Zilbandy)
>Subject: Re: The Physics of Boat Ramps
>Date: Wed, 20 Dec 1995 05:19:23 GMT
>jst...@azstarnet.com (Jerry Steele) wrote:
>>>Ron Morgan
>>>r...@bga.com
If it's snowing, should I put chains on the prop?
pa...@kahuna.nrl.navy.mil
mentioned....
You can get a dual rear wheel conversion kit for almost all mini and full size
pickups and 'burbs. They are listed in al issues of Four Wheeler mag. If
needed, I can get a phone from one of my back issues.
Since I have a 4x4 dually I "hope" i won't need any of the other tricks that
have been posted.
-Greg
Andy Champ
: My jeep has mushy rear springs and a short wheelbase, so I don't run with much
: tongue weight. You can usually run much more tongue weight on a real truck like
: yours. 300 or 400 lbs of tongue weight, if you are not already running that
: much, could do a lot for your traction problems. Check with the truck
: manufacturer to see what they recommend.
It occurrs to me to point out that for those of us with front wheel drive
tongue weight will make things WORSE!!
Andy
me...@cars3.uchicago.edu
>You might want to try a "bigger gear ratio" maybe something like 4.11 or
>4.56 in your rear end.
>
I don't use any gears in my rear end :)
Mati Meron | "When you argue with a fool,
me...@cars3.uchicago.edu | chances are he is doing just the same"
Rod Mc Innis
: The idea is to kinda simulate what anti-lock brakes do to help create an
: anti-slip traction control. When you get ready to pull out, keep your
: foot on the brake, hard. Push on the accelerator to get the engine RPMs
: up (and thus power), by spinning up the torque converter. This is kinda
: like those brake starts you used to do from a traffic light with Dad's old
: Galaxie 500. (Oh sure, like you never did it?!?) Now s-l-o-w-l-y lift
: pressure off of the brake until the vehicle and trailer just start to
: move. Then KEEP YOUR BRAKE FOOT IN THIS POSITION UNTIL YOU GET MOVING
: WELL UP THE RAMP. Modulate your speed with the brake foot. Leave the
: accelerator foot pretty far or all the way down. The brakes are helping
: to minimize wheel spin! Taa Daa... Poor man's traction control!
That's funny, this was exactly the technique I used to use when I
*wanted* the rear wheels to spin. You know, like when you were trying
to show off at the stop sign by lighting up the tires, without really
going anywhere? (all you people who are too young to have taken your
parents V8, heavy metal muscle car out on a date probably have no idea
what we are talking about.....)
By stepping on the brake, you make all four wheels resist turning.
When you step down on the gas, you make just the rear wheels want to
turn. Since the front wheels get a lot more of the braking power in
the first place, you can find a happy medium where the rear wheels
will break loose and start to spin (provided you have enough
horsepower) while the front brakes hold you still.
I fail to see how this helps you get up a wet launch ramp.
The basic technique I have used is once you get it moving, keep it
moving.
So there are several tricks on getting the rig moving. One trick is
to back the rig a little bit into the water, and then start
accelerting up the ramp while the boat is still floating. If your
trailer guides the boat into the proper spot without manual help, this
can work. Otherwise, this can create major problems.
Another way that I have used is to have someone in the boat, running
the engine. With the prop pushing a bit, you can get a good start.
Once the rig starts up the ramp, the boat person shuts off the engine.
Of course, this relies on a trailer rig that allows the prop to
operate while on the trailer. Not so good for some inboards.
The suggestion of letting air out of the tires is a good one. Works
for all forms of getting stuck: sand, snow, mud, etc. As you let air
out, the tire bulges and flattens where it hits the ground. The
difference between 25PSI and 32 PSI in traction is incredible. If you
are desparate, you can keep going down. A nearly flat tire can have
great traction, just don't drive on it too far.
Rod McInnis
TheMuskyDude
out of a boat ramp quickly shouldn't be at the launch. Here in the
midwest it is a complete joke. I (and all my fishing buddies) can
launch and be out of the way in under two minutes. That's why you
have a four wheel drive vehichle, have your tie downs off when you hit
the launch, have your drain plug in, get the boat off (or on) and get
out of the way. You see so many people who don't do it right, for
instance crank their tin boat on the trailer, it's ridiculous. There
is boat launch etiquite the same as fishing. Boat launches should be
monitored for improper usage, and violaters ticketed. If you don't
have the proper vehichle to use the launch you shouldn't use the launch.
I can't tell you how many hours of fishing have been wasted over
the years, just from something as simple as launching a boat.
My .02
Vince
Mark Crafts
Not really. Wet weather traction is basically "resistance to
hydroplaning" which isn't the problem here.
What you want Ron, is to get as much rubber touching the ground as
possible. That's why lowering the tire pressure works. The problem is
that wet-weather traction tires (and this includes truck tires and most
other knobby tires) have wider gaps to channel the water through which
means less rubber on the ground.
Go buy regular old passenger car tires for your truck. Unless you
regularly go offroad, the only differences you'll notice are a nicer
ride, cheaper tires, and easier boat extraction.
Mark
--
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
Mark Crafts Melbourne FL
mcr...@digital.net
"You only live once, but if you do it right, once is enough."
Jay Meeker
<suggestions deleted>
>These are all great suggestions, but people who can't get in and
>out of a boat ramp quickly shouldn't be at the launch. Here in the
>midwest it is a complete joke. I (and all my fishing buddies) can
>launch and be out of the way in under two minutes. That's why you
>have a four wheel drive vehichle, have your tie downs off when you hit
>the launch, have your drain plug in, get the boat off (or on) and get
>out of the way. You see so many people who don't do it right, for
>instance crank their tin boat on the trailer, it's ridiculous. There
>is boat launch etiquite the same as fishing. Boat launches should be
>monitored for improper usage, and violaters ticketed. If you don't
>have the proper vehichle to use the launch you shouldn't use the launch.
>I can't tell you how many hours of fishing have been wasted over
>the years, just from something as simple as launching a boat.
You're right Vince, I agree...to a point. EVERYBODY has to start some-
where, sometime with what they can *afford*. I myself am very lucky to
have found a used boat/motor/trailer that fit my needs very well but
my mule is a little short of hp. I'll be upgrading asaIcai (as soon
as I can afford it), but what I have is adequate for now.
As far as boat ramp etiquite, us (I have been boating for YEARS) old
pro's need to show a little patience to the newbie's. Remember, you
were there once too.
BTW (to those newbies), if you haven't taken a boating safety course
you should sign up NOW. I did (after 20-some years) and found I had
forgotten a few things and learned some new ones besides!
Safe boating to all!
And remember; Skip the drink, Skipper!
Jay
--
I'd rather be chasing walleye's...at Tenmile Lake!
Jason Paul Flores
one I use. I have a half-ton extended cab short bed GMC. plenty of power
with a limited slip diff. I pull a 3800+ boat trailer with no problem out
of the water. When ever I get to spinning I simply through two old towels
that I keep in the boat under the wheels and traction is mine.
Jim Dincau
>
> Conditions: a standard half-ton truck, attempting to pull a 3,000
> pound fishing boat up a fairly steep concrete launch ramp. The
> boat is on a 4-wheel trailer in good condition. The truck is,
> of course, rear-wheel drive, and has more than enough horsepower.
>
bumper. Keeps the rear wheels away from the water and up on the dry
part of the ramp, It's really helpful on ramps with a small slope
where you have to actually get the truck tires in the water.
D. Fortner
: Steve Das <sd...@sat.net> wrote:
:
: Not really. Wet weather traction is basically "resistance to
: What you want Ron, is to get as much rubber touching the ground as
: possible. That's why lowering the tire pressure works. The problem is
: that wet-weather traction tires (and this includes truck tires and most
: other knobby tires) have wider gaps to channel the water through which
: means less rubber on the ground.
: Go buy regular old passenger car tires for your truck. Unless you
: regularly go offroad, the only differences you'll notice are a nicer
: ride, cheaper tires, and easier boat extraction.
Err . . . not exactly, an all terrain tread has sharper edges on the
tread and a better ability to "bite through" (so to speak) the slime on
the ramp. I'm a big fan of the B.F. Goodrich All Terrain T/A, they (and
other tires of that type) do a LOT better on a slick ramp than highway
passager tires, not to mention a stiffer sidewall which greatly aids in
stability while trailering a heavy load.
Dave Fortner
for...@ddi.digital.net
pa...@kahuna.nrl.navy.mil
Terain. They have better wet traction than Goodyear Wranglers. I haven't
tried the Brigstone Dessert Dualler. Mud tires don't have as good a bite
on hard surfaces as they have smaller actual rubber contact.
In the "tricks" catagory....if your already on wet pavement, but the tires
are still relatively dry, water them down with a hose for 10-15 minutes.
Rubber is hydro-scopic and is much softer when wet, (wear on a wet road is
10 times as great as with a dry tire) so you will get better bite. This is
an old dirt-trackers trick for "cutting" tires to the track conditions. If
you soak the tire first you can easily contour the tread blocks with a razor
blade. On a dry tire it's nearly impossible without a special grooving
iron. You can easily see the change in the rubber texture once the tire has
soaked long enough, the pores are visably opened.
-Greg
>
Jim Kesterson
>
>Conditions: a standard half-ton truck, attempting to pull a 3,000
>pound fishing boat up a fairly steep concrete launch ramp. The
>boat is on a 4-wheel trailer in good condition. The truck is,
>of course, rear-wheel drive, and has more than enough horsepower.
>
>other boats that were just pulled out.
>
>My truck can just BARELY pull the boat up the ramp under these
>conditions. If it's dry, no problem, but when the ramp is wet,
>the tires slip and spin, sometimes even smoking. It's a very,
>very marginal situation. Last night, I came very close to being
>stranded at a deserted ramp after dark; I could *not* get that
>boat up that ramp, and finally made it up after creeping about an
>inch at a time, before the tires would slip. God only knows what
>kind of wear this produced on my transmission.
>
>Question: what kind of tire tread design would provide the *most*
>friction? Knobby, off-road type, or a smoother "pavement" type?
>Remember, by the way, that this is extremely low-speed operation,
>just barely turning, in fact, so concepts like "hydroplaning"
>probably wouldn't apply here. We're talking about pulling a load
>up a wet concrete surface.
>
>How about it, you guys? I need to buy new tires for my truck in
>another couple of months, and I'd appreciate some input. In addition,
>I think it'd make an interesting discussion topic, as well.
>
>Ron Morgan
>r...@bga.com
>
>
I'd be kind of leary of letting air out the back tires. Especially if you are
going to have to travel awhile before you can air them back up.
As for tires, All Terrains will be better than mud tires. There is more
surface area on an all terrain than a mud tire and therefore more contact
with the pavement. All seasons may be even better yet, although I've
never looked into them for use on a truck.
The extra weight with water is a pretty slick idea. And a limited slip
rearend would be the single most biggest improvement to it you could
make.
As for suggestions, try putting it into 1st gear and only giving it enough
gas to move. A little wheel spin may occur but is not necessarily a bad
thing. As for the hotter the tire gets the stickier it will become. Alittle is the
key word. You don't want to spin them so bad you get billowing clouds of
white smoke. Actually from your vantage point in the drivers seat, if you
can see smoke you are probably spinning them too much.
Just my one penny's worth.
-Jim K.
JerryO
From one of the previous replies, why won't snow tire chains work?
Mathew A. Mondro
Boy did you hit the nail on the head! where is the thought process when someone
is trying to launch or retrieve a 22 ft boat with a 2wd ranger or fwd passenger
car? I just dont get it. How many times i have waited for people who undo the
tie downs after they reach the bottom of the ramp or feel they need to put them
on as soon as the trailer tires touch land, if the ramp is crowded get the fuck
out of the way and do your cover and other related shit in the parking lot!
My favorite is the lazy ass who gets to the dock before you and walks slowly to his car and ties up the ramp for like ten minutes, not to mention the fact that it
takes him 10 tries at backing up the trailer correctly.
The boat launch is EXACTLY that, a launch, not a cooler clean out area, not an
arrange the car area, not a boat wipe off spot, and not someplace to dicuss your
day out. 2 minutes is adequite if youve planned your outing at all.
Matt
(Enjoying Winter)
joe.henderson
writes:
>You might want to try a "bigger gear ratio" maybe something like 4.11 or 4.56 >in your rear end.
This could be bad advice! If the problem is lack of power, then yes,
taller gears would help. If slippery conditions are the problem, the
gear change would make it worse. The truck would tend to break traction
easier. In fact, my Astro Van has a feature where you can start out in
second gear (yes, on an automatic) by shifting into second before pulling
away. This eases the power to the wheels instead of giving it full power.
Joe in NC, boatowner
steep ramps - done 'em: 95 Astro Van, 200 HP 4.3L, locking diff., 3.45
gears
pa...@kahuna.nrl.navy.mil
Chains should never be used on "dry" (no ice or snow) surfaces. They are
terrible for the ramp, will wear extremely quickly, and can (after just a
little wear) be thrown off the tire damaging the vehicle and bystanders.
Russ Crisp
>Ron Morgan
>r...@bga.com
Take a look at the Michelin LTX series. I got a set and I really like
them.
Regards,
rc
msta...@qualcomm.com
Being new to this string I wondered which solution you were going to try.
There was a lot of mention of tire types, gear ratios, etc, they may all
help but I wondered why weight was not discussed in more detail. I live
across the river from a boating resort and camp ground, and have seen
many ramps throughout the delta. I thought I would attempt to steer the
conversation towards the boat weight on the hitch especially on steep
ramps/low tide/ wet pavement. With enough hitch weight, any gear
ratio/tire tread/resonable horse power will pull most trailor sized boats
up the ramp.
Unfortunately, most boaters adjust the trailor balance on flat/level
ground for driving conditions which hurts them on the ramp. Adjust it on
the ramp if you can but it doesn't have to ba that heavy. I suggest
heaver driving configurations (move weight towards vehicle) so that it
has enough weight for the ramp. If the front boat attachment hook cannot
be moved having people in the front of the boat while on the ramp can
help(or in the back of the vehicle).
Another alternitive is to have two trailor tongues, a longer one to move
the weight back while driving and a short one while going up and down the
ramp. You may have to have this made, make sure you have a trailor jack.
You may see this in use in larger trailors that have a sliding tongue
that has a quick release pin that can be removed, the vehicle rolled back
slightly and the pin inserted again.
It doesn't sound like you have horse power problems nor tire tread
problems, try the above and let me know what you think before installing
new gears/tires/etc or before buying a new tow vehicle.
Best of luck,
marty
msta...@qualcomm.com
Mark Crafts
>Err . . . not exactly, an all terrain tread has sharper edges on the
>tread and a better ability to "bite through" (so to speak) the slime on
>the ramp. I'm a big fan of the B.F. Goodrich All Terrain T/A, they (and
>other tires of that type) do a LOT better on a slick ramp than highway
>passager tires, not to mention a stiffer sidewall which greatly aids in
>stability while trailering a heavy load.
Possibly, if there's that much slime. Ron's problem was that the ramp
was wet however, and I maintain that the more rubber on the ground the
better. Most of the ramps I use don't have much of a problem with slime
and normally I don't even need to drop into 4WD...
John Kennett
<huge snip>
>out of the way. You see so many people who don't do it right, for
>instance crank their tin boat on the trailer, it's ridiculous. There
>is boat launch etiquite the same as fishing. Boat launches should be
>monitored for improper usage, and violaters ticketed. If you don't
>have the proper vehichle to use the launch you shouldn't use the launch.
>I can't tell you how many hours of fishing have been wasted over
>the years, just from something as simple as launching a boat.
>My .02
>Vince
What do you reckon should be listed as boat launch etiquette? If we
can list it out, perhaps it would stop people having to learn the hard
way!
John
Rex
>My favorite is the lazy ass who gets to the dock before you and walks slowly to his car and ties up the ramp for like ten minutes, not to mention the fact that it
>takes him 10 tries at backing up the trailer correctly.
My favorite is the Husband & Wife team where the wife stands on the
dock and does absolutely nothing to help out.
My wife always backs the trailer. Hell, she can back it better than I
can. I jump in the boat, her in the truck and away we go. She backs
it in, I back the boat off and were done in a matter of minutes.
I've had a lot of guys come up to me and ask "How in the hell do you
get your wife to do that".
She has even jumped into someone else's truck and backed their rig in
when they had no idea what the hell they were doing. You wouldn't
believe the ribbing that fellow gets from his fishing buddies when my
wife backs his boat in.
I admit, I'm very lucky!
TheMuskyDude
How about a few already mentioned, tie downs off the boat, the proper
vehichle to launch, launch isn't the place you decide to clean your boat
and/or cooler, drive boat onto the trailer instead of cranking. Know
how to actually back a trailered boat in, and my personal favorite
calling someone on a cell phone and blocking the launch. Do I need to
continue? I'm sure other people can tell plenty of other horror
stories.
Oh by the way Merry Xmas.
Vince
Steve Cutchen
> >These are all great suggestions, but people who can't get in and
> >out of a boat ramp quickly shouldn't be at the launch. Here in the
> >midwest it is a complete joke. I (and all my fishing buddies) can
> >launch and be out of the way in under two minutes.
<snip>
Ya, been there... terribly frustrating to be at a crowded ramp having to
hold position in the current and wind... can't even get to the dock, while
some poor fool gums up the works. But, as long as YOU are not the one in
line, some of these ramp follies can be hillarious.
My brother and I got up one morning to go offshore (Freeport, Texas) only
to find the wind up pretty bad. Well, Hell, we had nothing better to do,
so we decided to go ahead and pull down to Freeport anyway. Praying for
Divine intervention, I guess. Got down there and the Coast Guard's 15
knot flag is stiff as a starched shirt.
We decided to continue on to our boat ramp, open a can of sardines for
breakfast (only the ones in Tabasco will do, ya know) fire up the radio
and see how folks were doing trying to break the jetties. There were a
surprising number of empty trailers... Well, seas were 5-7, and most
folks only poked their heads out before calling it a day and heading back
in. We spent the morning watching folks recover at the ramp. Man what a
circus. And not helped one bit by the wind, which was blowwing abeam of
boats trying to drive on. Maybe we didn't wet any bait that morning, but
we were thoroughly entertained!
---Steve
--------
Steve Cutchen If we always do what we've always done,
scut...@phoenix.net we'll always get what we've always got...
Shel Belinkoff
nomenclature for what is a typical, spring-loaded, clutch pack limited
slip differential.
Shel Belinkoff
beli...@netcom.com
_________________
=================
Sam (sa...@ix.netcom.com) wrote:
: Ron I had the same 'problem' with my old truck ('91 Dakota with
: limited slip). I would put up a slippery ramp and one tire would spin
: (no posi!)... I helped the situation by putting all of the crap in the
Gil Meacham
>From one of the previous replies, why won't snow tire chains work?
Besides tearing up the ramp, I think you'll find that chains have very little
traction on a hard surface they cannot dig down into. Soft tires with many
edges (like the new blizzak by bridgestone) will work much better on wet
cement.
acss...@acs.eku.edu
I can't get the wife to drive the truck at all if the boat is hooked up.
But she can load and unload the boat with the best of 'em.
Dudley Cornman
Systems Programmer
Academic Computing Services - EKU
ACSS...@ACS.EKU.EDU
********************************************************************
*** When it comes to boats... ***
*** I'd rather have a new boat than a used boat... ***
*** I'd rather have a Baja than a Bayliner... ***
*** I'd rather have a used Bayliner than no boat at all... ***
********************************************************************
acss...@acs.eku.edu
> What do you reckon should be listed as boat launch etiquette? If we
> can list it out, perhaps it would stop people having to learn the hard
> way!
Problem is, the people that may need it the most, probably can't spell
Internet, let alone use it.
For starters...
The ramp is for launching and retreiving only.
It is not for loading unloading suplies, working on the boat or trailer,
learning to back a trailer, etc. These tasks should be done in a staging
area away from the ramp, or at home, or at other appropriate locations.
It is not a parking space for boat or truck/trailer while dad does all
the driving/loading and the rest of the family sits by like helpless dim
wits. Moms and sons and daughters... thou shalt learn to load/unload the
boat or handle the truck/trailer or both! Dads... thou shalt teach moms
and daughters and sons to do these tasks! No sexual bias intended, if
appropriate for your family, reverse the roles of mom and dad above.
An exception can be made for any person that is alone at the ramp.
Launching by yourself is a bitch, but still doable in a reasonable
amount of time.
Pandion
scut...@phoenix.net says...
>
>TheMuskyDude <Vincent.R...@aasc.com> writes:
>
>> >These are all great suggestions, but people who can't get in and
>> >out of a boat ramp quickly shouldn't be at the launch. Here in the
>> >midwest it is a complete joke. I (and all my fishing buddies) can
>> >launch and be out of the way in under two minutes.
><snip>
I can remember the first couple of time..a nightmare but I didnt have
anyone like you waiting ..they might have laugh at me ,gave me some
advise but did understand... you should learn some patience and relax
thats what we are all out there to do..include catching fish...RELAX
Steve Cutchen
> In article <scutchen-221...@dial61.phoenix.net>,
> scut...@phoenix.net says...
> >
> >TheMuskyDude <Vincent.R...@aasc.com> writes:
> >
> >> >These are all great suggestions, but people who can't get in and
> >> >out of a boat ramp quickly shouldn't be at the launch. Here in the
> >> >midwest it is a complete joke. I (and all my fishing buddies) can
> >> >launch and be out of the way in under two minutes.
> ><snip>
> >Glad to hear YOU did it perfectly the first couple of times..Flame!
> I can remember the first couple of time..a nightmare but I didnt have
> anyone like you waiting ..they might have laugh at me ,gave me some
> advise but did understand... you should learn some patience and relax
> thats what we are all out there to do..include catching fish...RELAX
Uh... don't ya just hate it when people get their attributions mixed up?
NONE of these quotes are mine. Please be more careful.
TheMuskyDude
> scut...@phoenix.net says...
> >
> >TheMuskyDude <Vincent.R...@aasc.com> writes:
> >
> >> >These are all great suggestions, but people who can't get in and
> >> >out of a boat ramp quickly shouldn't be at the launch. Here in the
> >> >midwest it is a complete joke. I (and all my fishing buddies) can
> >> >launch and be out of the way in under two minutes.
> ><snip>
> >Glad to hear YOU did it perfectly the first couple of times..Flame!
> I can remember the first couple of time..a nightmare but I didnt have
> anyone like you waiting ..they might have laugh at me ,gave me some
> advise but did understand... you should learn some patience and relax
> thats what we are all out there to do..include catching fish...RELAX
I guess I'll have one final post on the subject. You know people
could actually practice (a novel concept) backing a rig up in a
parking lot with cones before they clog up the launch.
Vince
Sam
>> gear change would make it worse. The truck would tend to break traction
>> easier. In fact, my Astro Van has a feature where you can start out
in
>> second gear (yes, on an automatic) by shifting into second before
pulling
>
>I beleive the Astros use a 700R4 tranny, same as my S-Jimmy. I know if
I
>start my S-Jimmy in 2 gear, it starts in 1 gear and then changes to 2
>gear when the speed is right. What years was this option offered?
>
I believe only FORD has the feature of starting out in 2nd
gear...my '75, '76, & '88 E250's will start in 2nd. My friend's F-250
(460) & F-150 (302) with OD will start in second too.
...Sam
Mark J. Scango
> >> gear change would make it worse. The truck would tend to break traction
> >> easier. In fact, my Astro Van has a feature where you can start out
> in
> >> second gear (yes, on an automatic) by shifting into second before
> pulling
------clip
>
> I believe only FORD has the feature of starting out in 2nd
> gear...my '75, '76, & '88 E250's will start in 2nd. My friend's F-250
> (460) & F-150 (302) with OD will start in second too.
>
>
> ...Sam
I believe you're wrong, Sam. So does my '95 CHEVY..., and so does my third
cousins Blazer,who just happens to be twice removed on my mothers side.
(That's my cousin, not his blazer, by the way) ;-D
Just joking. But Chevy does, too. A nice feature in the snow belt.
--
Mark J. Scango mark...@mail.microserve.net
mark...@proshop.microserve.com
"With free advice, you get what you pay for"
David McRae
>
>Traction is a function of friction. Friction is related to mass, not
>surface area (tire size.) I would vote for lime ( or sand on the ground),
<Rest Deleted>
Friction = mass * coefficient of friction
The coefficient of friction is a function of many things: type of materials,
temperature, contact area, last meal eaten [just kidding :-) ]. Deflating the
tires, using larger tires or using a better tread pattern will all increase the
coefficient of friction, thus giving better traction. Note that by increasing mass
will also increase friction, but it is easier to deflate tires than go hunt for junk to
throw in the truck.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
David McRae (mc...@math.uab.edu)
Department of Mathematics
University of Alabama at Birmingham
http://www.math.uab.edu/home/mcrae/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C3TX
surface area (tire size.) I would vote for lime ( or sand on the ground),
Good luck
Steve Cutchen
> > We spent the morning watching folks recover at the ramp. Man what a
> > circus. And not helped one bit by the wind, which was blowing abeam of
> > boats trying to drive on. Maybe we didn't wet any bait that morning, but
> > we were thoroughly entertained!
Dudley Cornman, acss...@acs.eku.edu replied:
> Of course, between laughs, you did what you could to help out... right?
Actually, we did help folks out. Nothing major. Most folks do just
fine. We were mainly holding lines for folks, helping to direct (boat)
traffic, holding folks off of each other. And swapping stories about how
bad the seas were...
But there were some real amazing cases, so we were not just Good
Samaritans. Like the guy who was missing a roller on his trailer. It was
the type where there are several roller sets, in an H pattern, with the
pivot in ther center of the H. He was missing the aft inside roller and
needed someone to hold it against the pivot until the boat caught the
other three. Else he's punch a hole in the hull with the bare end of the
H.
Andy Dingley
>Friction is related to mass, not surface area (tire size.)
Friction is only independent of surface area in school textbooks. In
the real world (and this includes school physics labs), it depends on
area.
Neither is it true to say that bigger areas give more friction (in all
cases). All you _can_ say with any certainty is that the real world
situation is far more complex than simple tribology. For off-road
tyres, the amount of grip depends less on the friction available
between tyre and surface and more on factors like contact pressure
being high enough to change the characteristics of the surface (i.e.
squeezing the water out down to the dry tarmac) or tread chunkiness
being enough to generate a force between tyre and surface at the
macroscopic level.
--
Andy Dingley din...@codesmth.demon.co.uk
The Internet has given us all mountains of information at our fingertips.
...and all most people want to do is pick their noses with it.
Susan Dannenberg
remaining unchanged--mass, surface area, surface materials, etc--that
going to a relatively narrower tire would increase the coefficient of
friction because doing so will increase the pressure per square inch on
the (remaining) contact surfaces. (It is easier to scratch a piece of
glass with a thumb tack than with the flat of a putty knife.)
For this reason, I have always believed that narrow deep tread mud and
snow tires are better for cutting through and pulling a vehicle through
mud and snow than wide floatation tires that leave you slopping about on
top of the mud and snow*. Mightn't the same be true for ramps? And if so
doesn't deflating the tires have the opposite effect?
*(unless you are going for the snow shoe effect by using wide tires to
keep you from breaking through the snow. At one time--maybe
still--caterpiller tracks were manufactured for 4x4s that bolted on like
wheels. In profile they looked like enormous triangles and effectively
converted the vehicle into a snow cat. BTW, anyone out there know any
more about these?)
--David
Bill C.
a bit so it is less likely to drag in the snow. There is les snow to push
out of the way because of the narrower profile. I don't usually launch or
retrieve in snow drifts.
I think some of us may missed a disticntion between coefficient of
friction ( a mathematical term ) and "traction". They are certainly
related. If we reduce the width of that tire for use in snow drifts to
the width of a razor blade...
Bill
Rod Mc Innis
: re: coeffecient of friction: I always thought that all other variables
: going to a relatively narrower tire would increase the coefficient of
: friction because doing so will increase the pressure per square inch on
: the (remaining) contact surfaces. (It is easier to scratch a piece of
: glass with a thumb tack than with the flat of a putty knife.)
No, the coeffecient of friction is a constant between two materials.
It is also a generally useless constant in real life, as you are rarely
dealing with a situation where it applies.
As the contact area decreases, the PSI increases. Increase it
enough, and you will have enough force to break the surface tension of
a material, ie, scratch it.
: For this reason, I have always believed that narrow deep tread mud and
: snow tires are better for cutting through and pulling a vehicle through
: mud and snow than wide floatation tires that leave you slopping about on
: top of the mud and snow*. Mightn't the same be true for ramps? And if so
: doesn't deflating the tires have the opposite effect?
If there is firm ground underneath, the tall narrow tire will sink
through the mud and contact it.
What really comes into play with a tire against a roadway is not the
coeffecient of friction, but shear strength. The road is *not* a
smooth surface when discussing coeffecient of friction. The rubber of
the tire meshes with the courseness of the roadway. In order for the
tire to slip, either the roadway needs to tear, or the rubber needs to
tear.
Water tends to fill the tiny holes, reducing the amount of
penetration of the rubber. Thus, with less interlocking, it is far
easier to tear the rubber.
Adding weight will provided added pressure to force the water out of
the little holes, providing more shear area. Going to a wider
"footprint", by either using a wider tire or delflating the tires you
got, will spread the load over a larger road surface, allowing more
rubber to engage the available "tiny holes".
Using something like sand to replace the water in the little holes
will also improve traction, as the sand grains will wedge themselves
into the holes, where the water will just "flow".
Rod McInnis
Bruce Holms
>
>
> A CJ owner came to the rescue and attempted to pull the Chevelle out,
> but the weight of the Chevelle actually pulled the CJ towards the water.
> Then a 4X4 truck, with wench appeared and wenched the Chevelle, trailer,
> and boat to safety. The interior was soaked.
>
Aren't WENCHES great!? ;-)
--
Bruce Holms
bho...@itchy.nafb.trw.com
http://www.geopages.com/SunsetStrip/1082/
acss...@acs.eku.edu
>>surface area (tire size.) I would vote for lime ( or sand on the ground),
Please tell me more...
Take two tires identical in every way, except one is 6 inches wide and
one is 12 inches wide. On a hard wet surface (like a boat ramp) the
wider tire will usually spin first. If surface area has nothing to do
with friction (as it applies to this discussion), then friction has
noting to do with pulling a boat up a ramp.
Bob Immler
About 30 years ago my father had a friend that ordered a new ski boat, a
new trailer, and an SS396 Chevelle to tow it.
Those Chevelles came with a special hood with twin "hood scoops." But
when the car arrived, the battery in the car above it in the transporter
had leaked onto the hood. A new hood was ordered, painted and installed.
So it was time to take the boat out on the first
"adventure/"
My dad's friend started backing the boat and trailer down the ramp, but
the ramp was slick, and steep and the 400+ hp engine didn't help much at
this point and the trailer just kept going deeper and deeper into the
water. The more power was applied, the farther in the car slipped. Water
began entering the passenger compartment.
A CJ owner came to the rescue and attempted to pull the Chevelle out,
but the weight of the Chevelle actually pulled the CJ towards the water.
Then a 4X4 truck, with wench appeared and wenched the Chevelle, trailer,
and boat to safety. The interior was soaked.
The car was towed to a gas station and the engine, trans, and rear end
were drained and then refilled. The car started and ran well. The only
thing that didn't work was the speedometer, so it was taken back to have
that fixed under the warranty.
The service man called and said the car was ready, but he had a question
to ask. "This may sound stupid, but did you wash your car's interior
with a hose?"
"Of course I didn't do that." was the honest answer.
The guy said that was funny, because there was water in the speedometer
housing.
Nevertheless, the car was ready, but when the guy went down to pick it
up, it was missing from the lot. The service manager couldn't believe
the guy was so incompetent that he couldn't find his own car and walked
out onto the lot himself.
The Chevelle had been stolen.
When it was recovered the fancy, factory wheels were missing.
Bob Immler
Joseph Siddall
>Bob Immler wrote:
>>
>>
>> A CJ owner came to the rescue and attempted to pull the Chevelle out,
>> but the weight of the Chevelle actually pulled the CJ towards the water.
>> Then a 4X4 truck, with wench appeared and wenched the Chevelle, trailer,
>> and boat to safety. The interior was soaked.
>>
>
>
>
I wish my wench was that strong. I hate yardwork.
Joe
acss...@acs.eku.edu
>>> gear change would make it worse. The truck would tend to break traction
>>> easier.
This isn't necessarily true... especially for a standard tranny. The
lower gear ratio can allow you to start much smoother and use less
power, whereas a high ratio might require you to rev up and dump the
clutch (especially on under powered trucks on steep ramps).
For a test borrow any 4 wheel drive with manual front hubs and high/low
transfer case. First try towing a heavy boat (as defined by the capacity
of the truck) up a ramp. Then back it right back in and do it again in 4
wheel low range (hubs in the free position). Then tell me which is
better.
Rod Mc Innis
: Traction is a function of friction. Friction is related to mass, not
: surface area (tire size.) I would vote for lime ( or sand on the ground),
: Good luck
BZZZZZT! Wrong!
This is the basic answer that one arrives at had having taken just the
first year physics class, and not the class on practicle engineering.
Did you ever wonder why race cars use really wide tires?
If you live in a world that actually has frictionless pulleys,
springs that don't heat when they bend, air that doesn't influence
falling objects, and perfectly hard smooth surfaces, then what you
say would be true.
It is approximately true for for a train running on steel tracks.
It is far from true for rubber tires running on asphalt.
For a non-smooth surface, the rubber of the tire meshes with the
course, uneven roadway. What you now have is shear strength coming
into the equation. "Burning rubber" is the result of exceeding the
shear strength and tearing rubber from the tire.
When the surface is wet, the water will fill the very small recesses
of the road, preventing the rubber from fully meshing with the road.
This reduces the amount of tire subjected to the shear force, making
the slip much more likely. On dirt or gravel, the shear strength of
the roadway is generally less than that of the tire, and thus your
traction is less.
Rod McInnis
Clint Olsen
Rod Mc Innis <rmci...@adobe.com> wrote:
>C3TX (c3...@aol.com) wrote:
>: Traction is a function of friction. Friction is related to mass, not
>: surface area (tire size.) I would vote for lime ( or sand on the ground),
>: or greater weight over the back wheels---have someone sit in the bed.
>
>: Good luck
>
>BZZZZZT! Wrong!
Am I the only person who finds this behavior truly annoying? :)
-Clint
MARSHALL DUDLEY
-> BZZZZZT! Wrong!
->
->
-> This is the basic answer that one arrives at had having taken just the
-> first year physics class, and not the class on practicle engineering.
-> Did you ever wonder why race cars use really wide tires?
No, I know why. First the wider tire has more surface area so it can dissipate
heat quicker and not melt. A melting tire not only looses material at an
unacceptable rate, but it also looses traction. Secondly they make the tires
out of very very soft rubber for better traction, but this causes a very high
wear rate. By making the tire wider, it wears slower (more material). They
leave the tread off for the same reason, to get more material in there that is
going to wear off. And lastly the tires are tougher, if they hit something,
there is more rubber, more suface area, and more volume of air inside to absorb
the energy without busting the tire. However, for the most part the traction
does not change vs width unless the track is wet. Then the wide tire has much
LOWER traction than a standard tire of the same composition due to
hydroplaning.
Marshall
Pete Young
> Then a 4X4 truck, with wench appeared and wenched the Chevelle, trailer,
^^^^^
Somebody tell me where I can get one of these please!
--
____________________________________________________________________
Pete Young pyo...@srd.bt.co.uk Phone +44 1473 640885
"Just another crouton, floating on the bouillabaisse of life"
Jim Carr
>
>-> This is the basic answer that one arrives at had having taken just the
>-> first year physics class, and not the class on practicle engineering.
>-> Did you ever wonder why race cars use really wide tires?
mdu...@brbbs.brbbs.com writes:
>
>No, I know why. First the wider tire has more surface area so it can dissipate
>heat quicker and not melt. ...
... and a few other misconceptions.
For example, the rubber compound is matched to the car and conditions
so the tire is at the optimum temperature regardless of what size it is.
Ever do any racing? The wider tire sticks better, other things equal.
I got my first set of autocross tires from a road racer who had to run
in the stock 185-60 size rather than the 205-55 favored by autocrossers.
Two were rather worn, and I corded them after a few months. To help
manage my budget, I replaced them with 205-55 after talking to the folks
at BFG about the effects this might have on vehicle dynamics and how to
adjust to it and/or take advantage of it.
I put them on the back for two reasons. I tend to make two mistakes.
I sometimes lock up the brakes by not trailing enough as I turn in, so
better to have the older tires in the front where they will get torn
up instead of the expensive new ones. Although the car naturally tends
to understeer, I have a tendency to get into oversteer (spin) by mis-
managing the throttle in a slalom, and wider tires in back are supposed
to counteract that by increasing understeer.
Do they ever. The 205-55 is built specifically for the Miata so it has
been molded to the same circumference as the 185-60 stock tire. I run
it at the same pressure. There are some differences due to the sidewall,
but the BFG R1 has such a stiff sidewall you can't tell it is flat, so
this should be a minor effect. The only difference is that the tire is
about an inch wider so the footprint is wider and shorter. It has
*much* more traction than the tire it replaced.
The shape of the contact patch affects tire traction. Effects are even
more dramatic when you want to get up to the 3g limit of drag tires,
where you must maximize the contact area to minimize the force that
must be exerted by each little rubber molecule on the track.
--
James A. Carr <j...@scri.fsu.edu> | If you haven't been to Two Egg,
http://www.scri.fsu.edu/~jac/ | you haven't been to Florida.
Supercomputer Computations Res. Inst. |
Florida State, Tallahassee FL 32306 | -- Holder of Past Knowledge
Steve Cutchen
ols...@kodiak.ee.washington.edu (Clint Olsen) wrote:
BZZZZZT! Wrong!
I find it annoying, too!
derrick_weeks
>>>Traction is a function of friction. Friction is related to mass, not
>>>surface area (tire size.) I would vote for lime ( or sand on the ground),
>
>Please tell me more...
>
>Take two tires identical in every way, except one is 6 inches wide and
>one is 12 inches wide. On a hard wet surface (like a boat ramp) the
>wider tire will usually spin first. If surface area has nothing to do
>with friction (as it applies to this discussion), then friction has
>noting to do with pulling a boat up a ramp.
>
>
I agree that surface area has much to do with friction, but I think
that you have it backwards.
I must disagree with your assertion that the 6 inch tire will spin
before the 12 inch tire regardless of the type of surface. The
wider tire spreads the force over a larger area than the narrow
tire thereby reducing its tendency to break traction (spin). As you
probably can tell, I am no physicist, but I can think of a few
supporting examples: drag racer reduce spin with wide tires, to
increase traction 4 wheel drive vehicle will reduce tire pressure to
get more tire on the ground.
C. Wayne Parker
>In article <4crpii$c...@enquirer.mv.us.adobe.com>,
>Rod Mc Innis <rmci...@adobe.com> wrote:
>>C3TX (c3...@aol.com) wrote:
>>: surface area (tire size.) I would vote for lime ( or sand on the ground),
>>
>>: Good luck
>>
>>BZZZZZT! Wrong!
>
>Am I the only person who finds this behavior truly annoying? :)
>
>-Clint
No, you're not the only person. I thought it should have been spelled
BAAAAANT! Don't you just hate those spelling errors? The answer
following the BZZZZZT was, however, correct and justified.
--
C.W. Parker
Osborn Triffy Estevam Desa
Friction has everything to do with tire size - I studied it in a course on
Vehicle Dynamics.
To put it in a laymans perspective. Look at F-1 cars - they have wide tires for
better traction - they are are also smooth and if the course is wet - the race
may be called off as the smooth tires are deadly on wet roads (hydroplaning)
--
'''
(0 0)
*****************o00****(_)**********************************************
* *
* Osborn T Desa *
* ============= *
* email: o...@iastate.edu *
* *
* Address: *
* -------- *
* Office: Home: *
* 2043 Black Engineering Westgate 205A *
* Ames IA 50011 Ames IA 50012 *
Michael Sierchio
> This is the basic answer that one arrives at had having taken just the
>first year physics class, and not the class on practicle engineering.
>Did you ever wonder why race cars use really wide tires?
Well, the 1st yr. Physics model only applies to a tire whose wheel
is locked up -- then all of the laws of friction apply, and the
dynamic coefficient of friction rules. It then doesn't matter
what widthe the tire, just the compound.
When a tire is ROLLING, we aren't talking about friction at all --
not the same kind, anyway.
--
--------
Michael Sierchio mailto:ku...@dnai.com
http://www.dnai.com/~kudzu/
Gerald Luiz
I don't know if anyone has mentioned this or not but what we are really
interested in is how many g's can be exerted, i.e. move the vehicle. Friction
and mass are important but don't tell the full story. If we only use friction,
we could never get higher than 1 g but race cars pull many more than that. So
it is correct to say (as Rod has) that the shearing between the rubber and
surface accounts for something. The friction coef. will be constant for two
materials or constant enough to not make a large difference compared to the
shearing effect. Also, for a given vehicle, the contact area will be the
_same_ for any width tires at the same pressure; the contact patch shape
changes. Race cars use wide tires because it results in a _wider_ contact patch
with allows greater shear effects and lateral acceleration from friction. The
wider tires actually generate more heat (more rolling resistance) but the
surface area of the tire (i.e. diameter) counters this. Someone mentioned about
tires for autocrossing(?) and noticed a great handling improvement from wider
tires.
For our situation about going straight, we would like to have a _long_ contact
patch. At the same psi, we would prefer a narrow tire. This allows a greater
logitudial length for the shearing effect. Lowering tire pressure increases
the length of the patch more than the width of the patch. At low speeds,
hydroplaning is not a factor so the tread is not critical...long as there is
someplace for the water to go, i.e. some tread, not slicks. Raising psi is
good to get the tires to bite through snow, etc. if there is good stuff
underneath (smaller contact patch with greater pressure at the patch. F1 cars
want lateral accel so reduced pressure does not help. Plus the lower pressure
results in higher rolling resistance leading to slower cars, higher tire temp,
etc. Drag racers want a lower pressure to get this longer patch but still have
to go fast. They actuall spin the tires resulting in kinetic friction effects.
For drag racing, they want a large contact patch and it is easier to make it
wider than longer.
Rod Mc Innis
Please disregard the last half of my last post, regarding the
accelertion down the race track. I kind of left out a rather
significant factor, as I ran the calculation based on a mile instead
of the much shorter track......
Rod McInnis
Also, I have just noticed that this discussion is being cross
posted to a lot more newsgroups than I had intended. Sorry.
Coby Hughey
In article <4cufps$3...@news.iastate.edu>, o...@iastate.edu spouts...
>
>
>Friction has everything to do with tire size - I studied it in a course on
>Vehicle Dynamics.
You are getting friction and traction confused. Traction includes the
component of friction, not vice versa.
>To put it in a laymans perspective. Look at F-1 cars - they have wide tires
for
>better traction - they are are also smooth and if the course is wet - the
race
>may be called off as the smooth tires are deadly on wet roads (hydroplaning)
>--
>
>
> '''
> (0 0)
>*****************o00****(_)**********************************************
>* *
>* Osborn T Desa *
>* ============= *
>* email: o...@iastate.edu *
>* *
>* Address: *
>* -------- *
>* Office: Home: *
>* 2043 Black Engineering Westgate 205A *
>* Ames IA 50011 Ames IA 50012 *
--
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Coby Hughey :Motorcycles
aka Snakeman :4x4's
Colorado :Snakes
Herpetological:Computers
Society :and anything I
:haven't tried yet
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
MARSHALL DUDLEY
I wouldn't be so sure of that. He claims that on a slick surface like a boat
ramp more area in contact will increase traction. I don't believe it, so I
tried an experiment yesterday in my front yard. Since our yard is covered with
snow now, I walked up and down my hill several times on the sides of my shoes,
so that I presented a narrow "width". No problem. Then I tried it with the
sole of my shoe, and every time I slid to the bottom of the hill. The
difference was unmistakable, the wider contact area has much much less
resistance to slipping.
Marshall
Jim Carr
>
> .... If we only use friction,
>we could never get higher than 1 g but race cars pull many more than that.
The first part is not true.
The coefficient of friction between rubber and some surfaces, for
example, asphalt with a rubber coating, is around 4-5 according to
the CRC. The carbon added to give street tires long life reduces
this to a much smaller number in the 0.9 territory, but you can buy
tires (treadwear rating allegedly 050, but more like 010) with a
compound that exceeds 1.2 if you don't mind the wear rate. Drag
racers could not exceed 3 g at launch if not for the rubber compound
they use and the rubber-coated concrete they launch from since they
must get a static coefficient of 3 or more to do that.
> ... The friction coef. will be constant for two
>materials or constant enough to not make a large difference compared to the
>shearing effect.
But it is the shearing effect that makes the coefficient of friction a
variable rather than a constant when you operate over a wide range of
conditions. Otherwise, what you write about size and shape of the
contact patch fits my experience.
Steve Cutchen
> Rent a slip in the marina and sit at the dock laughing at all the trucks
> stuck pulling boats out of the water...I do
And have to scrape and paint the bottom every year? Or are you in
straps... :-)