Building an adult trike
Dave Johnson
haven't found a used (or new) one within budget. I'd like to try
building one. I can braze,and I think I can handle the frame
construction, However, I'm not so sure about the drivetrain. Before I
go through a bunch of experimentation, I'd like to learn from the
experience of anyone else who's tried this
Will single wheel drive work?
How about a solid axle, with no freewheel or differential?
Separate freewheels for each drive wheel? I think I could manage this
with BMX freewheels.
Something else entirely?
Sheldon Brown
> My mother in law is interested in an adult trike, but so far, I
> haven't found a used (or new) one within budget. I'd like to try
> building one. I can braze,and I think I can handle the frame
> construction, However, I'm not so sure about the drivetrain. Before I
> go through a bunch of experimentation, I'd like to learn from the
> experience of anyone else who's tried this
>
> Will single wheel drive work?
Yes, for light duty, low speeds.
> How about a solid axle, with no freewheel or differential?
Nope.
> Separate freewheels for each drive wheel?
Possible, but this would greatly add to the complexity of the design.
Left wheel drive is the usual way to go in the abscence of a
differential, and affordable differentials are no longer to be had.
You might be able to find to find a conversion kit that would work.
Note that with a trike, you can put the bottom bracket considerably
lower than with a bike, since it doesn't need cornering clearance.
Trikes are generally a major hemorrhoid, not recommended if theres'a any
possibility of her riding a bike. They're amazingly cumbersome and
awkward, also generally more dangerous than bikes.
Sheldon "Not Talking About Recumbent Tadpoles" Brown
+----------------------------------------------------+
| A little inaccuracy sometimes saves tons of |
| explanation. --H.H.Munro ("Saki")(1870-1916) |
+----------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com
Bruce Lange
In college I worked on a project building an adult trike, delta style. It
didn't have a differential per se, but the rear wheel hubs had needle
bearings that would engage (and be driven by) the axle, but which could also
allow the wheel to "freewheel" faster than the axle, allowing the outer
wheel to properly track through a turn. We found this preferable to strict
one-wheel drive. With one wheel drive, your legs can really tell that it's
only the one wheel doing the driving, and right turns feel a lot different
from left turns.
The rear hubs were a simple design, with standard needle bearings
pressed-in. We used a solid rear axle, but made a special piece to attach a
freewheel to it (the axle ran right through the freewheel). I don't remember
what that thing looked like. Sure helps to have access to a machine shop.
I've also seen true differential units on tricycles at Sears. They might be
able to order you just the differential or axle unit. Two-wheel drive will
definitely take more effort to build, but I think it's worth it. We have the
technology. :)
Check with the HPV/recumbent crowd; lots of trike enthusiasts there, and
lot's of people who build their own HPVs.
http://www.ihpva.org/ is a great place to start. Has lot's of trike designs
in the Builder's Corner.
Good luck with your project,
-Bruce-
"Dave Johnson" <djohns...@spamblocked.com> wrote in message
news:dqi67vg1qbqer1av3...@4ax.com...
M-Gineering import & framebouw
something along the lines of :
http://www.freewiel.nl/uk/uk/producten/trike.html
makes more sense to me
--
Marten
A Muzi
I've built a lot of custom vehicles ( mostly for disabled children) and
find that just buying a trike rear end assembly from Trailmate is very cost
effective. I get the subframe with bearings and shafts in primer and the
buy their hubs.
http://www.yellowjersey.org/photosfromthepast/trikjn95.jpg
http://www.yellowjersey.org/photosfromthepast/trikturq.jpg
And yes, one wheel drive is standard for that sort of thing.
Write me if you do not have a local Trailmate dealer.
--
Andrew Muzi
http://www.yellowjersey.org
Open every day since 1 April 1971
Steve Palincsar
> Trikes are generally a major hemorrhoid, not recommended if theres'a any
> possibility of her riding a bike. They're amazingly cumbersome and
> awkward, also generally more dangerous than bikes.
Here's what Aedan Mcghie, a very happy owner of a George Longstaff
tricycle has to say on the subject:
<http://ourworld.compuserve.com/homepages/triker/technique.html>
<quote>
If you ride a trike for any length of time you are going to get very fed
up with people asking "Can't you ride a bike?". The best (but risky) way
to stop this is to let them have a shot. Generally within a few feet they
will panic and jump off or stay on and turn turtle. Then you can get a
photo like the one above showing the underside of a trike.
They assume that because, left to itself, a trike will stand up that it is
easy to ride. It is a completly different experience from riding a bike.
The UK Tricycle Association Gazette had an article about learning to ride
a trike last year. They said that it took time to learn and would never be
mastered, the trike always has a surprise waiting for you.
Riding in a straight line is the first challenge. A trike will try to run
off down the camber of the road. On a bike you steer the way you are
falling to correct the problem. If you do that on a trike it just makes
things worse. You have to dissconect what you feel like you are doing and
focus on what really is happening. It's OK for a trike to sit at an angle.
If there is any camber on the road then there is nothing you can do
anyway, it will sit at whatever angle the road is at. If the angle starts
to get steep then steer a little up the camber. Trust your trike to look
after itself and things will become fine. Fight it and you are heading for
a fall.
Once you have mastered the straight line you are faced with a corner. On a
bike you steer with you weight and balance with the steering. A trike is
just the opposite. You steer with the steering and keep it upright with
your weight. Using the handlebars to steer takes a bit of getting used to.
At first I was worried that the latteral loading on a wirespoke wheel
would cause it to taco. You have to apply much more force to the steering
than you do with a bike. When you figure out how to steer you then have to
worry about falling over. If you sit on the saddle then sooner or later
you are going to meet a bend which causes your centre of gravity to move
outside the triangle of the wheels. When that happens you will roll. To
avoid this you should move your weight to the inside of the bend. The
tighter or faster the curve the further out you should move. It works the
same way as a motorcycle side car team.
Inspite of the above my trike is my mount of choice. This is not only
because if its safety but mainly...
BECAUSE IT"S FUN!
</quote>
Here's what he says about one wheel drive vs two wheel drive:
<quote>
Trikes can be one wheel drive or two wheel drive (OWD or TWD).
One Wheel Drive is simpler to do and is lighter. Generally the wheel
nearest the kerb is the driven wheel as this tends to push the machine up
the camber of the road and makes life a bit easier. On ice or snow a one
wheel drive trike will move at a slight angle to the direction of travel.
Lifting a wheel off the ground is easy to do and if it is your driven
wheel which is off the ground then life can seem empty and meaningless.
Some trikes have been fitted with car style differentials but, as anyone
who has ever driven on snow is aware, car diffs send the power to the
faster wheel. This can be the one on the outside of the curve, the one
with less grip on the road... or the one up in the air.
Longstaff two wheel drive uses a double freewheel block which sends the
drive to the wheel with most grip, generally this is the one on the
ground. It can be difficult to understand how this works, the easiest way
is to think that the faster wheel is freewheeling.
The only problem I have found with this system is that when doing very
tight turns, in it's own length, the inside wheel can slip a little.
The rear axle runs on sealed bearings, one at each end of each half shaft.
The rear wheels are held on in the same way as a crank is attached to a
bottom bracket except the axle is six sided rather than four.
</quote>
McGhie owns a George Longstaff tricycle with two wheel drive.
<http://ourworld.compuserve.com/homepages/triker/axle.JPG> is a picture of
the differential.
I have a Longstaff frame (bicycle, not trike) and I can attest to the
craftsmanship of this builder. His trikes are said to be the best
available, and if one is serious about an English Racing Tricycle, his are
the trikes to get.
Dave Johnson
found a used (or new) one within budget. I'd like to try building one.
I can braze,and I think I can handle the frame construction, However,
I'm not so sure about the drivetrain. Before I go through a bunch of
experimentation, I'd like to learn from the experience of anyone else
who's tried this
Will single wheel drive work?
How about a solid axle, with no freewheel or differential?
Separate freewheels for each drive wheel? I think I could manage this
with BMX freewheels.
Something else entirely?
--
If love is blind, why is lingerie so popular?
Dave Johnson
>Dave Johnson wrote:
>> Will single wheel drive work?
>
>Yes, for light duty, low speeds.
>
..which this would be.
>> Separate freewheels for each drive wheel?
>
>Possible, but this would greatly add to the complexity of the design.
Seems like this would be almost exactly twice as hard as single wheel
drive. Shouldn't I be able to reverse a BMX freewheel for the opposite
side? Isn't that what the wrong-side-drive BMX bikes do?
>
>Note that with a trike, you can put the bottom bracket considerably
>lower than with a bike, since it doesn't need cornering clearance.
>
I was planning on that.
>Trikes are generally a major hemorrhoid, not recommended if theres'a any
>possibility of her riding a bike. They're amazingly cumbersome and
>awkward, also generally more dangerous than bikes.
I don't disagree, but there's no realistic chance of getting her on a
bike.
--
Ignorance killed the cat.
Curiosity was framed.
David L. Johnson
> Will single wheel drive work?
Proabably the best option.
>
> How about a solid axle, with no freewheel or differential?
That will corner strangely, with one wheel skidding. Remember that a
trike will be subjected to a lot of weird things like slow sharp turns.
>
> Separate freewheels for each drive wheel? I think I could manage this
> with BMX freewheels.
That would be a mess. And unless one of the chains would be
outside the right wheel, one of the freewheels will have to be backwards,
or attached in some weird way. Your MIL will not notice any significant
difference between single-wheel drive and this set-up unless she likes to
go through a lot of mud.
I would suggest using an extra shaft so the drive chain can
be in a normal position, driving the shaft which then connects to a
fixed cog and second chain to the left rear wheel. That would keep most
of the components available off-the-shelf, such as the hubs. Probably
you'd need some sort of wheelchair axles, which might or might not be
compatible with a standard hub. You could even set up the
half-shaft with a derailleur and muti-gear freewheel.
--
David L. Johnson
__o | Accept risk. Accept responsibility. Put a lawyer out of
_`\(,_ | business.
(_)/ (_) |
Bikefixr
as well, if at all. The brazing is the eay part. Most adult trikes stink.
Period. Too heavy, limited choises, beyond-bad positioning, flex and wobble.
The English take a quality mountain bike and add a trike conversion kit. Bob
Jackson makes a sweet one as do a few others. These are real high kits-sealed
bearings, support struts, freewheeld, derailleured etc....They use a single
wheel drive as using a dual wheel offers no real advantage for the people that
ride these. It's been done, but it's a LOT of work to derive a differential to
allow for cornering. The kits usually sell in the $500-750 range, install in a
bout 2 hrs, and nothing is permamanent. Take it off and revert the bike to orig
spec. I sold them in my shop for years-mostly to elderly people that wereafraid
of falling or to people with neurological/physical deficits that wanted to ride
but coudn't ride a std bike or the terrible adult trikes.
Jeff Wills
>
> I've built a lot of custom vehicles ( mostly for disabled children) and
> find that just buying a trike rear end assembly from Trailmate is very cost
> effective. I get the subframe with bearings and shafts in primer and the
> buy their hubs.
>
> http://www.yellowjersey.org/photosfromthepast/trikjn95.jpg
> http://www.yellowjersey.org/photosfromthepast/trikturq.jpg
>
> And yes, one wheel drive is standard for that sort of thing.
> Write me if you do not have a local Trailmate dealer.
As Andy said, there are conversion kits for modifying standard diamond
frames. These used to be (long ago) available from Schwinn dealers.
You might want to ask the local Goodwill people where all their bikes
go to- generally they're sent to the bigger warehouses instead of the
smaller Goodwill stores (at least that's how it works here in
Portland). A *real* find would be a Schwinn Town & Country
three-wheeler- this had a three-speed hub driving a true differential
on the rear axle. I don't think they've been made for 20 years- but
they were damn sturdy.
If "Mom" wants something really exotic, she should contact Pat Franz
at Terracycle. He built a carbon-fiber trike for a balance-challanged
Special Olympics rider: http://www.terracycle.com/cftrike.htm
Jeff
nospam@attbi.com Jay
http://www.justtwobikes.com/trike.htm
Jay
"Dave Johnson" <djohns...@spamblocked.com> wrote in message
news:t8jv6v0on75p2juue...@4ax.com...
Bluto
> Sheldon Brown wrote,
>
> >> Separate freewheels for each drive wheel?
> >
> >Possible, but this would greatly add to the complexity of the design.
>
> Seems like this would be almost exactly twice as hard as single wheel
> drive. Shouldn't I be able to reverse a BMX freewheel for the opposite
> side? Isn't that what the wrong-side-drive BMX bikes do?
Left side drive BMX bikes use special left-side, left-hand-threaded
freewheels and hubs. If you want to "wrong-side" a freewheel I'd
suggest using one of those.
At the speeds within which a conventional "delta" trike is competent,
single-wheel drive does work pretty well.
You could use a trike conversion kit like this
http://www.megalowrider.com/Item/F9901.htm on a bicycle frame. This
one is intended for 20" wheels, but it does not appear that there is
anything to prevent its use with larger rims laced to appropriate
hubs. And as Sheldon pointed out, a trike BB need not be nearly as
high as a bike's, so 20 inch rear wheels might work just fine. It's
not like you're apt to screw up the handling, after all-- not
significantly worse than "normal" anyway.
Some Schwinn trikes came with sub-frames that used an ordinary pair of
bike wheels, the "rear" being used to drive the assembly. If you
could find one of those, it would allow the use of freely available
parts for both wheels and main frame.
Folks who fear falling from bikes and favor trikes for that reason are
apt to give up on trikes as well before too long. Trikes really are
treacherous, ill-tempered beasts by comparison, which will soon
confirm any weenie rider's suspicion that cycling is a terribly
hazardous undertaking.
Chalo Colina