About mid September I started to ride my 20" Schwinn on our mountain bike
trails up here in north Jersey just for kicks. After some
adjustment/practice I was able to move around on mild up/down hill terrain
without pitching off too much. The challenge of maneuvering through
irregular terrain, rocks, roots, mud, cants and logs was something I found
interesting. It's also a damn good workout! As a mountain biker, I always
enjoyed technical riding more than fast downhill stuff. Muni riding
offered yet another dimension in riding technical. Plus people look at you
in the parking lot in disbelief. There faces painted with, "He's not
really going in the woods on that thing." It's all part of the fun of a
muni ride. With the proper skill, a unicycle is a very capable player in
the woods. In all sports, aside from good technique, having the correct
equipment is important in helping one achieve proper performance. I
figured the 20" wheel was just a bit too small for off-road riding. Common
sense tells one that a larger wheel diameter will travel faster and roll
over irregular terrain more easily. The two popular rim sizes larger than
20", in bicycle stuff, are 24" and 26". I chose 26" because of the large
variety of mountain bike tires and rims available. I would have loved to
outfit my SemCycle XL or Schwinn with a Michelin wildgripper hot S tire
and hit the trails. Unfortunately, its wasn't going to be that easy. The
wildgripper hot S is 2.1" wide. The SemCycle XL with its tubular fork does
not have the clearance for a 2.1" wide tire. Also the SemCycle crank arm
length (mine is 5") is too short. Given the way the SemCycle fork is made
it didn't make any sense to attempt a modification either. I started to
look around for a professionally made mountain unicycle (muni for short)
and came up with Pashley and DM. After reading items on the NG it seemed
that a new Pashley muni would need a different rim, tire, seat and
possibly a hub to set it up for comfortable off-road riding. Perhaps these
opinions of the Pashley are falsehoods. Never having owned or riden the
Pashley muni I couldn't say fact or fiction. I sent an e-mail to DM and
didn't receive much in the way of useful information back so I decided to
build my own custom muni. On Monday 11/1/99 I drove to Frank's Bike Shop
in New York City and purchased a Schwinn 24" unicycle (about $160.00). It
was a 2-1/2 hour round trip because Canel St. was a zoo due to ongoing
road construction. The Schwinn is made in Taiwan but its symmetrical
chrome plated steel frame design allowed for the type of modifications I
needed. For those not familiar with the Schwinn frame, it's made from two
identical stampings facing one another. It's held together with one bolt
passing through a frame rail, seat post and out through the other frame
rail. In other words, the frame rails sandwich the seat post. Once the
bolt is tightened the assembly is very strong. SImple. The bearings are
pressed into holes in the frame rail (interference fit). Snap rings fitted
in left and right grooves in the bearings provide additional support.
Schwinn's hub is 3-1/4" wide mounted in an inside frame opening of 3-3/4".
Just perfect. I removed the cranks arms and pulled the frame rails with
bearings off the axle. I took some measurements and found the two rails to
differ no more than several thousands of an inch in any dimension. Very
good accuracy for inexpensive parts. To accomodate the 26" rim and tire I
increased the length of the frame rails by 2-1/2". This was done by
cutting each rail 6" up from the bottom with a jig saw. Rough cut frame
segments (4 total) were squared and trued in a milling maching to preserve
accuracy. Two clearance holes were then bored (8 total) in each frame
segment to allow 1/4-20 SS button head cap screws to be used for rejoining
the frame segments. Using 6061-T6 1/2" aluminum two risers were machined
to increase the length of the fork providing room for the 26" rim/tire.
Each riser was drilled and tapped (8 places total) to allow assembly with
previously mentioned screws. Frame rails were then reassembled. The hub
was taken to a bike shop and fitted with a Mavic D321 disc rim (36 spoke).
The D321 is wide enough to accept a 3.0 tire if desired. It's also one
damn tought rim. The rim was fitted with the hot S 2.1" tire. The muni was
reassembled with 6.5" alloy crank arms and
9/16" Shimano BMX type pedals (the ones with little screws in them). The
Viscount seat was replaced with the old style Schwinn seat. A 12" inner tube
was added under the seat cover for that air ride that’s so comfortable. I’ve
been riding/falling the muni for two weeks now. Crank arms needed to be
retightened after the first time out but have since stayed tight. Same deal
with the pedals. They tend to loosen up after riding backwards alot. Overall
the munifications yielded a nice looking setup which rides pretty well too.
I’ve been hopping alot and riding off ledges/rocks to the tune of about 8-10"
and the hub, rim and spokes seem to be holding up except for a little clicking
when force is applied to a left rear pedal. Maybe just the spokes moving on
one another. The 26" tire sure is sweet. We’ll see what happens as time goes
by. Perhaps I’ll break before the equipment does. My last ride left my left
shin with a ding or two. Gotta love it! I look forward to someone coming out
with a good muni that’s ready to go out of the box. Building your own is very
time consuming but can be fun if you enjoy making things as I have over the
years. Next up I’ll be adding a disc brake. Once I get the hub designed I’ll
be on the down hill. <grin> Look for a part 2 covering that saga.
At 02:09 PM 11/23/99 GMT, Scott Bridgman wrote: >>From Muniac Manor - Building a Muni (Part 1) >On Monday 11/1/99 I drove to Frank’s Bike Shop in New York City and purchased a >Schwinn 24" unicycle (about $160.00)
Nice write-up on the Schwinn conversion. For your next project, why not take the
unused rim, tire, cranks, and pedals, and build an ultimate wheel?
I broke the axle on my Schwinn 24" early this summer and I wasn’t even MUni
riding, just learning how to hop. I’d be interested to hear how well your
Schwinn axle holds up with some good MUni abuse.
-Rick
> > About mid September I started to ride my 20" Schwinn on our mountain bike > trails up here in north Jersey just for kicks. After some > adjustment/practice I was able to move around on mild up/down hill terrain > without pitching off too much. The challenge of maneuvering through > irregular terrain, rocks, roots, mud, cants and logs was something I found > interesting. It’s also a damn good workout! As a mountain biker, I always > enjoyed technical riding more than fast downhill stuff. Muni riding > offered yet another dimension in riding technical. Plus people look at you > in the parking lot in disbelief. There faces painted with, "He’s not > really going in the woods on that thing." It’s all part of the fun of a > muni ride. With the proper skill, a unicycle is a very capable player in > the woods. In all sports, aside from good technique, having the correct > equipment is important in helping one achieve proper performance. I > figured the 20" wheel was just a bit too small for off-road riding. Common > sense tells one that a larger wheel diameter will travel faster and roll > over irregular terrain more easily. The two popular rim sizes larger than > 20", in bicycle stuff, are 24" and 26". I chose 26" because of the large > variety of mountain bike tires and rims available. I would have loved to > outfit my SemCycle XL or Schwinn with a Michelin wildgripper hot S tire > and hit the trails. Unfortunately, its wasn’t going to be that easy. The > wildgripper hot S is 2.1" wide. The SemCycle XL with its tubular fork does > not have the clearance for a 2.1" wide tire. Also the SemCycle crank arm > length (mine is 5") is too short. Given the way the SemCycle fork is made > it didn’t make any sense to attempt a modification either. I started to > look around for a professionally made mountain unicycle (muni for short) > and came up with Pashley and DM. After reading items on the NG it seemed > that a new Pashley muni would need a different rim, tire, seat and > possibly a hub to set it up for comfortable off-road riding. Perhaps these > opinions of the Pashley are falsehoods. Never having owned or riden the > Pashley muni I couldn’t say fact or fiction. I sent an e-mail to DM and > didn’t receive much in the way of useful information back so I decided to > build my own custom muni. On Monday 11/1/99 I drove to Frank’s Bike Shop > in New York City and purchased a Schwinn 24" unicycle (about $160.00). It > was a 2-1/2 hour round trip because Canel St. was a zoo due to ongoing > road construction. The Schwinn is made in Taiwan but its symmetrical > chrome plated steel frame design allowed for the type of modifications I > needed. For those not familiar with the Schwinn frame, it’s made from two > identical stampings facing one another. It’s held together with one bolt > passing through a frame rail, seat post and out through the other frame > rail. In other words, the frame rails sandwich the seat post. Once the > bolt is tightened the assembly is very strong. SImple. The bearings are > pressed into holes in the frame rail (interference fit). Snap rings fitted > in left and right grooves in the bearings provide additional support. > Schwinn’s hub is 3-1/4" wide mounted in an inside frame opening of 3-3/4". > Just perfect. I removed the cranks arms and pulled the frame rails with > bearings off the axle. I took some measurements and found the two rails to > differ no more than several thousands of an inch in any dimension. Very > good accuracy for inexpensive parts. To accomodate the 26" rim and tire I > increased the length of the frame rails by 2-1/2". This was done by > cutting each rail 6" up from the bottom with a jig saw. Rough cut frame > segments (4 total) were squared and trued in a milling maching to preserve > accuracy. Two clearance holes were then bored (8 total) in each frame > segment to allow 1/4-20 SS button head cap screws to be used for rejoining > the frame segments. Using 6061-T6 1/2" aluminum two risers were machined > to increase the length of the fork providing room for the 26" rim/tire. > Each riser was drilled and tapped (8 places total) to allow assembly with > previously mentioned screws. Frame rails were then reassembled. The hub > was taken to a bike shop and fitted with a Mavic D321 disc rim (36 spoke). > The D321 is wide enough to accept a 3.0 tire if desired. It’s also one > damn tought rim. The rim was fitted with the hot S 2.1" tire. The muni was > reassembled with 6.5" alloy crank arms and >9/16" Shimano BMX type pedals (the ones with little screws in them). The > Viscount seat was replaced with the old style Schwinn seat. A 12" inner tube > was added under the seat cover for that air ride that’s so comfortable. I’ve > been riding/falling the muni for two weeks now. Crank arms needed to be > retightened after the first time out but have since stayed tight. Same deal > with the pedals. They tend to loosen up after riding backwards alot. Overall > the munifications yielded a nice looking setup which rides pretty well too. > I’ve been hopping alot and riding off ledges/rocks to the tune of about > 8-10" and the hub, rim and spokes seem to be holding up except for a little > clicking when force is applied to a left rear pedal. Maybe just the spokes > moving on one another. The 26" tire sure is sweet. We’ll see what happens as > time goes by. Perhaps I’ll break before the equipment does. My last ride > left my left shin with a ding or two. Gotta love it! I look forward to > someone coming out with a good muni that’s ready to go out of the box. > Building your own is very time consuming but can be fun if you enjoy making > things as I have over the years. Next up I’ll be adding a disc brake. Once I > get the hub designed I’ll be on the down hill. <grin> Look for a part 2 > covering that saga. > >“The Muniac” Scott Bridgman scott@enduco.com > >
> I would have loved to outfit my SemCycle XL or Schwinn with a Michelin > wildgripper hot S tire and hit the trails. Unfortunately, its wasn’t going to > be that easy.
Scott, have you seen the new Semcycle Deluxe Muni that www.unicyclesource.com is
selling? Looks like a really good unit. They also sell the Pashley & the DMATU.