Which is more flat resistant?
Ken Bessler
700x25 road slick?
The reason I'm asking is while I've had 1 flat in the last 100 miles
on the road bike, my 12 year old son has had 4 in the last 5 miles,
despite my cautions to "stay on the pavement". His tubes are
starting to look like patch city. The flats are always caused by
tumbleweed thorns.
Ken
Ken Bessler
"Ken Bessler" <kg...@yahoo.com> wrote in message
news:cLqcnbTNtr7...@comcast.com...
> Which is more flat resistant - a 24x1.195 MTB knobby tire or a
> 700x25 road slick?
>
Sorry that's a 24x1.95, not 1.195...D'oh!
Pete Biggs
> Which is more flat resistant - a 24x1.195 MTB knobby tire or a
> 700x25 road slick?
Kobbies tend to be simply because there is more rubber to penetrate.
Other factors like compound hardness and kevlar belts are less important.
> The reason I'm asking is while I've had 1 flat in the last 100 miles
> on the road bike, my 12 year old son has had 4 in the last 5 miles,
> despite my cautions to "stay on the pavement". His tubes are
> starting to look like patch city. The flats are always caused by
> tumbleweed thorns.
He's still riding over more thorns than you are!
You may be able to find him some tyres with deeper knobs - although they
won't be so efficient and comfortable as slicks on the pavement. Newer
and better tyres may help anyway if existing ones are well worn cheap
ones.
~PB
Rick Onanian
> Which is more flat resistant - a 24x1.195 MTB knobby tire or a
> 700x25 road slick?
More data is required; a general comparison would
probably be worthless.
I'd expect a MTB tire to be tougher, but many 700x25
road slicks are kevlar-belted, and many 24" MTB tires
are really cheap.
> The reason I'm asking is while I've had 1 flat in the last 100 miles
> on the road bike, my 12 year old son has had 4 in the last 5 miles,
> despite my cautions to "stay on the pavement". His tubes are
> starting to look like patch city. The flats are always caused by
> tumbleweed thorns.
Is he right against the edge of the road, and you
ride a few feet out?
I'd bet he has cheap tires and you have good ones.
> Ken
--
Rick Onanian
Mike Mullen
larger contact patch so there is less weight on anything sharp you run over
will not be pressed as hard into the rubber. I've had really good luck with
fat slicks from a flat perspective. I think sometimes the knobs of a knobby
can help lever sharp items into the tread but I'm not familiar with the
problems of tumbleweed thorns and whether this is an issue.
But given identical widths and carcass construction I would expect a slick
to get less flats than a knobby. In your example I would expect the narrow
slick to have more flats because it is only half as wide as the knobby.
Mike Mullen
Ken Bessler
"Rick Onanian" <spam...@cox.net> wrote in message
news:oprvahu4...@news.east.cox.net...
> On Wed, 10 Sep 2003 06:56:00 -0600, Ken Bessler <kg...@yahoo.com> wrote:
> > Which is more flat resistant - a 24x1.195 MTB knobby tire or a
> > 700x25 road slick?
>
> More data is required; a general comparison would
> probably be worthless.
>
> I'd expect a MTB tire to be tougher, but many 700x25
> road slicks are kevlar-belted, and many 24" MTB tires
> are really cheap.
>
>
> ride a few feet out?
>
> I'd bet he has cheap tires and you have good ones.
>
> > Ken
> --
> Rick Onanian
I have Discovery Kevlar CyclePro 700x25 tires, he
has the stock 24x1.95 MTB tires that came from
Wal-Mart where I bought the bike. Also, his tubes
are suspect - I replaced the front tube (it exploded)
with a LBS bought heavy duty thorn resistant one
and now all the flats are in the rear stock tube.....
Thanks for the tips/advice!
Ken
Alex Rodriguez
>Which is more flat resistant - a 24x1.195 MTB knobby tire or a
>700x25 road slick?
Too many variables. How much air in the tires? How thick is the tread
on the tires?
>The reason I'm asking is while I've had 1 flat in the last 100 miles
>on the road bike, my 12 year old son has had 4 in the last 5 miles,
>despite my cautions to "stay on the pavement". His tubes are
>starting to look like patch city. The flats are always caused by
>tumbleweed thorns.
You need to teach him to recognize the thorns and ride around them.
-----------------
Alex __O
_-\<,_
(_)/ (_)
Ken Bessler
"Alex Rodriguez" <ad...@columbia.edu> wrote in message
news:bjnkik$npl$2...@newsmaster.cc.columbia.edu...
Better yet I'm going to start taking the repair costs out
of *his* income......
I must say I am getting a lot of experience repairing flats....
LOL
Ken
jobst....@stanfordalumni.org
"They" are puncture vine thorns (goatheads) aka Tribulus Terrestris:
http://www.or.blm.gov/Prineville/weed/puncture.htm
http://tinyurl.com/d0xo
Unless your son is picking up all his goatheads only ON the knobs, he
would have as many flats. I think you are riding along a different
route than he. Get to know how the plant looks and avoid it. Just
as with poison oak, those who suffer most from it have no idea how the
plant looks. Other riders aren't plagued by this enough to mention.
Just keep your eyes open.
Puncture vine grows only on barren soil and will not compete with
roadside grasses.
http://draco.acs.uci.edu/rbfaq/FAQ/9.34.html
Jobst Brandt
jobst....@stanfordalumni.org
Peter Cole
In the case of something that's guaranteed to cause a flat, like a tack (or
thorn, I guess), the bigger the "target", the greater the probability.
R15757
Goathead thorns.
Tribulus thorns laugh at "thorn resistant" tubes, kevlar belts, slime tubes,
etc. That sh** is worthless. Sometimes the knobbies of an MTB tire are big
enough that thorns stuck in them don't reach tube. But the thorns as you know
eventually get stuck through the thin part of the tire.
Only cure for goatheads is to ride where others have ridden or walked before.
Your son gets the thorns because he hauls off across a vacant lot somewhere. If
he stays on the pavement, or even on the well-worn dirt paths, he will get
about 90% less thorn flats. Figure out what the plant looks like. Shouldn't be
too hard. Then you'll know what you're up against. It's all over the durn
place. But the beauty of the goathead thorn is that it goes many more places
than just where it grew up.
Good thing you're getting some flat fixing practice. In goathead country,
you'll need it. Don't forget to carefully run your fingers all around the
inside of the tire after you think you've got all the thorns out, just to be
sure.
Robert
welcome to goathead country
Werehatrack
> Don't forget to carefully run your fingers all around the
>inside of the tire after you think you've got all the thorns out, just to be
>sure.
I prefer to check using either a cotton ball or a pair of discarded
nylons; the damn thorns are sometimes still a trifle sharper than I
want to sacrifice a finger on, but they'll snag and pull on either of
the things mentioned. (The latter in particular, but that's a hard
thing to justify having in the spares bag.)
At present, to my *intense* relief, it appears that puncture vine
remains absent from this area. I'm pretty sure that it was the same
nasty beast we had in parts of the Miami area some forty years ago,
though. The pictures looked way too familiar. Those spines would go
right through a cheap tennis shoe's sole. I went a long time without
running into it, until I had to pry some out of a pair of sandals a
couple of times on my last visit to the left coast. (That's where I
became acquainted with the cotton ball or other highly snaggable fiber
trick.)
--
My email address is antispammed;
pull WEEDS if replying via e-mail.
Yes, I have a killfile. If I don't respond to something,
it's also possible that I'm busy.
Peter Cole
In the case of something that's guaranteed to cause a flat, like a tack (or
A Muzi
news:e5rvlv0sp8g2lpt9c...@4ax.com...
> On 11 Sep 2003 02:08:32 GMT, r15...@aol.com (R15757) may have said:
>
> > Don't forget to carefully run your fingers all around the
> >inside of the tire after you think you've got all the thorns out, just to
be
> >sure.
>
> I prefer to check using either a cotton ball or a pair of discarded
> nylons; the damn thorns are sometimes still a trifle sharper than I
> want to sacrifice a finger on, but they'll snag and pull on either of
> the things mentioned. (The latter in particular, but that's a hard
> thing to justify having in the spares bag.)
>
> At present, to my *intense* relief, it appears that puncture vine
> remains absent from this area. I'm pretty sure that it was the same
> nasty beast we had in parts of the Miami area some forty years ago,
> though. The pictures looked way too familiar. Those spines would go
> right through a cheap tennis shoe's sole. I went a long time without
> running into it, until I had to pry some out of a pair of sandals a
> couple of times on my last visit to the left coast. (That's where I
> became acquainted with the cotton ball or other highly snaggable fiber
> trick.)
Myth. Having run my fingers inside literally many thousands of tires,
often with nicely mounted glass shards, staples, wire, nails and evey
imaginable penetrating object, I cannot recall ever having cut my finger
while wiping the inside of a tire. It may be theoreticallypossible but it
is unknown in the industry. Cotton ball indeed.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
David Damerell
>Myth. Having run my fingers inside literally many thousands of tires,
>often with nicely mounted glass shards, staples, wire, nails and evey
>imaginable penetrating object, I cannot recall ever having cut my finger
>while wiping the inside of a tire.
I have once, on a flint. However, I don't think it's worth buggering about
with cotton balls to prevent one trivial injury in many years of riding.
--
David Damerell <dame...@chiark.greenend.org.uk> Kill the tomato!
Dave Lehnen
>
> Myth. Having run my fingers inside literally many thousands of tires,
> often with nicely mounted glass shards, staples, wire, nails and evey
> imaginable penetrating object, I cannot recall ever having cut my finger
> while wiping the inside of a tire. It may be theoreticallypossible but it
> is unknown in the industry. Cotton ball indeed.
> --
Rare but not a complete myth. I've never cut my own, but a friend
last year cut his finger enough to bleed profusely, on a glass
shard. He was rushing the job, trying not to keep the group waiting
too long. If you use reasonable caution, low speed and light finger
pressure, not even the sharpest debris will cut deep enough to draw
any blood.
Dave Lehnen
jobst....@stanfordalumni.org
>>> I prefer to check using either a cotton ball or a pair of
>>> discarded nylons; the damn thorns are sometimes still a trifle
>>> sharper than I want to sacrifice a finger on, but they'll snag and
>>> pull on either of the things mentioned. (The latter in
>>> particular, but that's a hard thing to justify having in the
>>> spares bag.)
>> Myth. Having run my fingers inside literally many thousands of
>> tires, often with nicely mounted glass shards, staples, wire, nails
>> and every imaginable penetrating object, I cannot recall ever
>> having cut my finger while wiping the inside of a tire. It may be
>> theoretically possible but it is unknown in the industry. Cotton
>> ball indeed.
I'll second that!
> Rare but not a complete myth. I've never cut my own, but a friend
> last year cut his finger enough to bleed profusely, on a glass
> shard. He was rushing the job, trying not to keep the group waiting
> too long. If you use reasonable caution, low speed and light finger
> pressure, not even the sharpest debris will cut deep enough to draw
> any blood.
Oh the bloody horror of it. This sort of story and "it happened to a
friend..." is what propagates this myth. With intent to get cut,
even the inner edge of the tire bead can be a hazard while running the
thumb around the inside of the tire. It is the thumb with which this
exercise is best performed, it having a large enough surface and
roundness to cover the area of interest inside the tire.
Jobst Brandt
jobst....@stanfordalumni.org
Brent Olson
I got a wire from a steel belted car tire in my rear wheel. Running
my fingers around the inside, the wire split the tip of my index
finger. I wasn't wearing gloves. I fixed the tire and left some
blood all over the tire during the repair.
David Damerell
[cutting fingers on debris inside tyres]
>Oh the bloody horror of it. This sort of story and "it happened to a
>friend..." is what propagates this myth.
It didn't happen to a friend, it happened to me. That doesn't mean the
resulting injury - a tiny nick and a drop of blood - was worth worrying
about, mind...
Werehatrack
<dame...@chiark.greenend.org.uk> may have said:
><jobst....@stanfordalumni.org> wrote:
>[cutting fingers on debris inside tyres]
>>Oh the bloody horror of it. This sort of story and "it happened to a
>>friend..." is what propagates this myth.
>
>It didn't happen to a friend, it happened to me. That doesn't mean the
>resulting injury - a tiny nick and a drop of blood - was worth worrying
>about, mind...
Mine was worse; the small scar on my finger is still visible
thirty-odd years after I first got cut that way. I got a lot more
careful after that, but still collected the odd snag or scrape, and
then fairly recently someone who lives in the land of cholla spines
showed me the other trick, although it wasn't explicitly for tires in
that case. If the materials are at hand, what's the harm in using
them? But hey, if anybody doesn't want to use that technique, they're
free to ignore the suggestion, because that's all it was.
Werehatrack
may have said:
>I got a wire from a steel belted car tire in my rear wheel. Running
>my fingers around the inside, the wire split the tip of my index
>finger. I wasn't wearing gloves. I fixed the tire and left some
>blood all over the tire during the repair.
Car tires, of course, are almost always steel belted, but bike tires
aren't, so that's not a hazard here.
jobst....@stanfordalumni.org
>> I got a wire from a steel belted car tire in my rear wheel.
>> Running my fingers around the inside, the wire split the tip of my
>> index finger. I wasn't wearing gloves. I fixed the tire and left
>> some blood all over the tire during the repair.
> Car tires, of course, are almost always steel belted, but bike tires
> aren't, so that's not a hazard here.
"Michelin wires" are common debris on roads from worn through car
tires. They can be picked up by bicycle tires, mainly rear tires
although I have found them in front tires on a couple of occasions.
Being tiny, the braille method is the only way to find them, since
they do not protrude from the tread.
Jobst Brandt
jobst....@stanfordalumni.org
Werehatrack
I had thought he was speaking of a broken wire on the interior of a
car tire; sorry. (That, by the way, is far from unknown as a hazard
for car tire people.)
Short pieces of sharp steel wire are too familiar to me; I used to use
a lot of lockwire.
Chris Zacho The Wheelman
through anything. Kevlar, Tuffy's Thorn"proof" tubes, possibly all three
inj combination.
This is really not a fair competition. :-3)
May you have the wind at your back.
And a really low gear for the hills!
Chris
Chris'Z Corner
"The Website for the Common Bicyclist":
http://www.geocities.com/czcorner
Carl Fogel
Flat tire threads rarely include much data, probably because few
riders pedal the same route day after day, year after year. My
riding habits may be dull enough to be pertinent.
Since 1986, I've ridden the same route nine days out of ten. It's
just over 15 miles and takes me about 48 minutes, at an average
of just under 20 mph. I live in Pueblo, Colorado, on the bluffs
above the Arkansas River.
My first 6 miles run through the cottonwoods along the river on a
bicycle path. I can't remember half a dozen flats here.
Six miles up the path is a two-mile wide dam. I turn onto a paved
road and ride up a long prairie slope to the top of the bluffs
about 400 feet above the river according to the USGS map.
Most of my flats occur on the 5-mile round trip up and down from
the river to the top of the bluffs. One major cause is road
debris, such as glass, nails, tacks, staples, and fish-hooks.
(I've never found a cactus needle in a flat tire, probably
because the needles aren't shed and lie flat on the road.)
The other major cause of my flats is quarter-inch stickers, the
puncture vine briars shaped like caltrops.
Back along the other side of the river, I pedal past a gravel
pit, so I also get flats from tiny sharp-edged rock chips that
resemble dark glass.
In 1997, 1998, and 1999, I rode an old Schwinn touring bike with
thick-walled thorn-resistant tubes, Mr. Tuffy protector strips,
and 27-1/4" tires.
year rides miles rear front total
---- ----- ----- ---- ---- ---
1997 319 4785 2 1 3
1998 330 4950 8 0 8
1999 349 5235 11 1 12
--- ---- ---- --- --
998 14970 21 2 23
I averaged one flat every 650 miles and one front flat to 10 rear
flats.
In 2000, I bought a used 1998 Schwinn LeTour, partly because it
was a better bike and partly because most wheels and tires are
700c. I also switched from Mr. Tuffy protector strips and thorn-
resistant tubes to Slime tubes (with green sealant and white
clogging fibers), having read that that protector strips increase
rolling resistance noticeably.
My switch was arguably disastrous.
year rides miles rear front total
--- --- --- --- --- ---
2000 349 5235 18 15 33
2001 339 5085 16 13 29
2002 343 5145 36 17 53
--- ---- -- --- ---
1031 15465 70 45 115
I averaged one flat every 134 miles and suffered one front flat
for every two rear flats. The 700c tires and Slime tubes went
flat five times as often during a thousand rides in three years
on the same route.
It seems unlikely that the huge increase in flats was due to any
change in my riding skill or habits, so I reluctantly conclude
that the thorn-resistant tubes and plastic strips offer far more
protection than sealant and normal tubes where stickers and road
debris are a problem.
Recent experience suggests that riding habits can reduce flats,
though not in the way commonly suggested in these threads. Given
thousand of stickers per mile lurking amidst sand, pebbles,
gravel, cracks, and pitted road surfaces, it is unlikely that
riders can spot and swerve around all these tiny stickers at 25
mph to 40 mph downhill while paying attention to other vehicles,
intersections, and scenery. In some areas, you might as well try
to ride between rain drops as to avoid every sticker.
I changed my riding habits at the end of September, 2002. During
the worst drought in Pueblo's history, I had already had 45
flats, more than one per week. Stickers tend to be worse in dry
years, possibly because they colonize areas where other plants
have died, possibly because the general withering allows the wind
to spread the stickers more easily.
I stopped riding on the six-foot shoulder of the road, crossed
the rumble strip, and began riding on the white line in the
extreme right side of the traffic lane, where there's less debris
and fewer stickers. In the last three months of 2002, I had only
8 more flats. I wasn't spotting and avoiding any stickers, just
riding on a cleaner surface.
For much of 2003, riding away from the shoulder worked well.
Through August 17th this year, I had only 10 flats in 217 rides
and 3,255 miles, only one flat every 325 miles.
Unfortunately, I had 7 flats in the next ten days. Although
puncture vine may flower year-round in warmer climates, Pueblo's
worst season is August through September. Nothing flowers here in
the winter.
As many riders have argued, avoiding obvious road hazards reduces
flats. But it also helps to live where there are fewer stickers.
On a route prone to flats, thick-walled thorn-resistant tubes and
plastic strips seem to be markedly superior to Slime sealant, but
are likely to suffer more from rolling resistance.
Perhaps someone will post some data or calculations comparing the
rolling resistance of plastic strips versus the internal drag
caused by Slime.
It's worth noting the argument that Slime tubes are unsafe
because slippery, sealant-covered flat tires may cause loss of
control. Most of my flats occur on routes so undemanding that
light aircraft can land on the road, so I haven't had this
problem. However, I've had Slime tubes go soft so slowly that I
haven't noticed and then had trouble when a half-mile straight
ended in a sharp corner.
Dave Lehnen
> Dave Lehnen writes:
>>Rare but not a complete myth. I've never cut my own, but a friend
>>last year cut his finger enough to bleed profusely, on a glass
>>shard. He was rushing the job, trying not to keep the group waiting
>>too long. If you use reasonable caution, low speed and light finger
>>pressure, not even the sharpest debris will cut deep enough to draw
>>any blood.
>
>
> Oh the bloody horror of it. This sort of story and "it happened to a
> friend..." is what propagates this myth. With intent to get cut,
> even the inner edge of the tire bead can be a hazard while running the
> thumb around the inside of the tire. It is the thumb with which this
> exercise is best performed, it having a large enough surface and
> roundness to cover the area of interest inside the tire.
>
> Jobst Brandt
> jobst....@stanfordalumni.org
Wow, I thought I was right there when it happened, but apparently I
wasn't, since Jobst has labelled this and the other reported
incidents mythical. Didn't say he bled to death by the side of the
road, just that he cut his finger fairly badly and wouldn't have if
he'd been more careful.
Dave Lehnen
R15757
<< It seems unlikely that the huge increase in flats was due to any
change in my riding skill or habits, so I reluctantly conclude
that the thorn-resistant tubes and plastic strips offer far more
protection than sealant and normal tubes where stickers and road
debris are a problem.
>>
Thank you Carl for posting this data. Your results are intriguing due to the
commonly held notion that goathead thorns (the caltrops you mention) can
conquer any thorn-resistant tire, tube, or kevlar belt. As written, your data
is not complete enough to undermine this assumption. What we really need to
know is: how many goathead flats did you have before the change, and how many
after. A detailed breakdown of the types of flats--goathead, glass, tack,
whatever--would be most helpful.
I see you had many front flats 2000-2002. The ratio front : rear is about 2 :
3, as opposed to 1 : 10 1997-99. To me, all those front flats say goathead,
unless...another important question is--how many pinch flats have you had and
did you include them in the posted data?
One must also take into account that tribulus growth seems to vary from year to
year. If your route got inundated with tribulus in 2000, that alone could
explain the difference.
Thanks again Carl,
Robert
also in goathead country
Carl Fogel
Regrettably, I can only speculate about the causes of many
of my flats because the culprit does not remain in the tire.
I entertain, for example, dark suspicions about Russian
olive trees and their inch-long thorns, but have never found
one in my tire. True, I saw no other likely suspects in the
area, but I couldn't prove what punched the horrible hole in
my sidewall.
Sometimes the thorn of a sticker remains in the tire or I
see the sticker still stuck into my sidewall, but sometimes
the sticker punctures the tire and is then torn off intact
the next time that the tire turns. The tiny puncture
suggests a sticker, but it could be something else. Other
riders have complained about flats caused by wires so tiny
that they're hard to see and must be located by running a
finger along the inside of the tire, but I routinely check
my flat tires by feel and haven't had such a problem yet.
I suspect that stickers cause most of my slow leak front
flats. They tend to attack front tires instead of rear tires
because their thorns are already poised to impale the first
thing that runs over them. The front tire may even protect
the rear tire by sweeping many stickers aside.
Rear flats are more common and dramatic. I suspect that road
debris attacks rear tires more often than front tires
because most debris lies flat on the road until the front
tire rolls over it. I've never suffered an abrupt rear flat
while toiling up the long slope on my daily ride at only 10
mph, probably because my slow-rolling front tire throws up
less debris and because the debris lands and is lying flat
again when my slow-rolling rear tire arrives. It's coming
back down the same slope at 25 mph to 40 mph that I hear an
abrupt whoosh-whoosh-whoosh as the Slime sprays out a large
hole in my rear tire.
As for "pinch" flats, there was only one and it was dubious.
Some people "pinch" tubes when replacing them by squeezing
the tube so hard against the rim with a tire lever that the
rubber splits. This is almost impossible if you use your
fingers instead of tire lever, which doesn't require gorilla
paws. Unlike motorcycle tires, most bicycle tires are too
flimsy to resist proper tire-changing technique.
The other kind of "pinch" flat occurs when a tire hits
something so hard that it squeezes the inner tube against
the rim and cuts it. Low tire pressure makes this much more
likely, but I inflate my tires to 120 psi. In 2001, I had a
flat that might have been an impact puncture, judging by my
experience with impact punctures in motorcycle competition,
but later it occurred to me that an unnoticed slow leak
might have guaranteed an impact puncture when I hit a piece
of gravel.
As far as I can tell, my records of flat tires reflect no
sudden flourishing of stickers in the Pueblo area, much less
along my route. Not much has changed where I ride since
1986. The stickers have been a problem since I began riding
bicycles here as a child in 1963. In town, stickers are
rarely a problem. In fact, I bicycled through my high school
years without a single flat tire. But outside the city, the
lawns vanish and the stickers prevail.
What my records show is a fairly abrupt five-fold increase
in flats when I switched to Slime sealant from Mr. Tuffy
plastic protector strips and thick-wall thorn-resistant
tubes. Given two thousand rides, six years, and thirty
thousand miles over the same 15-mile route with the same
rider, it's hard not to conclude that Slime offers far less
protection from flats.
None of this addresses integral Kevlar belts, which many
riders consider useless. Jobst Brandt offers a good
argument, namely that Kevlar belts are really meshes, so
thorns and nails poke right through them like needless going
through steel wool. Solid plastic protector strips, on the
other hand, seem to offer considerable resistance.
R15757
<snip>
<< None of this addresses integral Kevlar belts, which many
riders consider useless. Jobst Brandt offers a good
argument, namely that Kevlar belts are really meshes, so
thorns and nails poke right through them like needless going
through steel wool. Solid plastic protector strips, on the
other hand, seem to offer considerable resistance.
>>
Thanks again Carl. I am a freak and find this very interesting. Since I've been
in Denver, I estimate 70% of my flats have been thorn-related; about 25% glass;
and 5% other, including random foreign objects and pinches. I have never used
the plastic strips.
Robert