Best crank size for 12" sem

Best crank size for 12" sem

Post by Nyc.. » Fri, 08 Jun 2001 00:51:24


My 5 yr old just started learning on a 12" sem which came with 4" cranks from
unicycle.com.  (John - it's great).

They lower pedal is 1/2 inch from the ground when the cranks are vertical,
meaning, he can't lean right or left.  I think this is hindering him a bit in
the learning process.

For this wheel size and age, these cranks are LONG.  I can ride his 12" in a
straight line, but to turn I cannot lean, but instead must do a standstill,
then rotate my body along a vertical axis.  (Talk about circus clowns!) Of
course for a beginner, this is impossible.

When my son attempts to ride, a pedal will hit the ground and knock him off
balance.    He doesn't want anyone holding his hands, he just wants to get on
it and keep trying.  I'm sure his persistence will pay off, but I'm wondering
if he might be better off with 3 or 3.5 inch cranks (assuming they are
available).

Anyone else out there have kids riding the 12" sem?

Joe

 
 
 

Best crank size for 12" sem

Post by John Hoote » Fri, 08 Jun 2001 07:03:58

My Scout troop has a 12" Sem. We have the same problem, although a few of the
guys can turn by leaning. They seem to do it by straightening up the wheel when
the inside pedal is down. It isn't smooth it's:
turn-straight-turn-straight-turn, but it also isn't squaring to direction you
want to go and then jerking the uni around . Of course we only use the 12" uni
for fooling around, and not for learning to ride on. I have taught younger kids
to ride on a 16" uni without this particular problem. Could your son fit on a
16" uni?

As I recall the 12" Sem XL came with 110mm cranks (about 4.3") which I replaces
with 102mm cranks (4") that I got from Unicycle Source.  I'm sure the 8mm
difference helps. You might want to check the length carefully and switch to
102's if they are 110. At Unicon X many of the Japanese freestyle riders rode
20" Miyatas with tiny cranks, I think they were 98mm or something like that. The
short cranks helped with spins and really smooth one foot skills, etc. I checked
with John Drummond, he didn't have any. He said he would look into getting some.
I'm sure they would help.

John Hooten

Quote:

> My 5 yr old just started learning on a 12" sem which came with 4" cranks from
> unicycle.com.  (John - it's great).

> They lower pedal is 1/2 inch from the ground when the cranks are vertical,
> meaning, he can't lean right or left.  I think this is hindering him a bit in
> the learning process.

> For this wheel size and age, these cranks are LONG.  I can ride his 12" in a
> straight line, but to turn I cannot lean, but instead must do a standstill,
> then rotate my body along a vertical axis.  (Talk about circus clowns!) Of
> course for a beginner, this is impossible.

> When my son attempts to ride, a pedal will hit the ground and knock him off
> balance.    He doesn't want anyone holding his hands, he just wants to get on
> it and keep trying.  I'm sure his persistence will pay off, but I'm wondering
> if he might be better off with 3 or 3.5 inch cranks (assuming they are
> available).

> Anyone else out there have kids riding the 12" sem?

> Joe


 
 
 

Best crank size for 12" sem

Post by John Fo » Fri, 08 Jun 2001 06:36:26

Quote:
> My 5 yr old just started learning on a 12" sem which came
> with 4" cranks from unicycle.com.  (John - it's great).

I think 4" is pretty long for a 12" wheel. I don't know how long the cranks
are on my own 12" unicycle, but they must be shorter. The pedals still hit
the ground when I turn, but I know there's at least 1" clearance *after* I
sit on the uni and the tire compresses.

Quote:
> meaning, he can't lean right or left.  I think this is
> hindering him a bit in the learning process.

It may not be too bad for learning to ride forward, but it is if it keeps
knocking him off. Regardless of rider size/weight, I think you want shorter
cranks.

Quote:
> a standstill, then rotate my body along a vertical
> axis.  (Talk about circus clowns!) Of
> course for a beginner, this is impossible.

Actually beginners usually turn using action-reaction in a relatively
clownlike motion (flailing). But still you need enough pedal clearance to
lean.

My 12" was made by Tom Miller from a disassembled, high-end children's bike.
This gave me a decent rim with adjustable spokes, a real three piece
cottered crankset (Tom had to make the hub), and some juvenile pedals. The
little pedals are narrower than ***-sized pedals, so they increase the
lean angle before they touch the ground. You could try getting some smaller
(narrower) pedals as a temporary fix. But the closer your pedal is to the
ground in the first place, the less difference this will make.

Since this is a low-stress unicycle (even an *** probably won't be doing
curbs on it), if you can't find shorter cranks you can probably get them cut
and welded back together. I'm sure they will last the lifetime of the cycle
unless your son grows up to be Dan Heaton or Adam Rysnar...  :-)

Stay on top,
John Foss, the Uni-Cyclone

www.unicycling.com

"Someone who thinks logically is a nice contrast to the real world."

 
 
 

Best crank size for 12" sem

Post by dingema » Fri, 08 Jun 2001 07:42:57

Quote:
> My 5 yr old just started learning on a 12" sem which came with 4" cranks from
> unicycle.com.  (John - it's great).

> They lower pedal is 1/2 inch from the ground when the cranks are vertical,
> meaning, he can't lean right or left.  I think this is hindering him a bit in
> the learning process.

> For this wheel size and age, these cranks are LONG.  I can ride his 12" in a
> straight line, but to turn I cannot lean, but instead must do a standstill,
> then rotate my body along a vertical axis.  (Talk about circus clowns!) Of
> course for a beginner, this is impossible.

> When my son attempts to ride, a pedal will hit the ground and knock him off
> balance.    He doesn't want anyone holding his hands, he just wants to get on
> it and keep trying.  I'm sure his persistence will pay off, but I'm wondering
> if he might be better off with 3 or 3.5 inch cranks (assuming they are
> available).

> Anyone else out there have kids riding the 12" sem?

    Recently somebody in the twin cities made a 12" to fit a very small little
girl.  My dad made some 3" cranks for it.  I think they seemed to work ok from
what I could see(I wasnt allowed to ride it).

    -Max A. Dingemans

 
 
 

Best crank size for 12" sem

Post by Klaas B » Sat, 09 Jun 2001 06:37:57


Quote:
>I think 4" is pretty long for a 12" wheel. I don't know how long the cranks
>are on my own 12" unicycle, but they must be shorter. The pedals still hit
>the ground when I turn, but I know there's at least 1" clearance *after* I
>sit on the uni and the tire compresses.

Your *-ing out the word "after" makes me wonder how much clearance
there would be *during* your sitting on the uni.

Quote:
>"Someone who thinks logically is a nice contrast to the real world."

I'll take that as a compliment today :-)

Klaas Bil
--
"To trigger/fool/saturate/overload Echelon, the following has been picked automagically from a database:"
"crack, USS Harry S. Truman, FBI"

 
 
 

Best crank size for 12" sem

Post by John Hoote » Tue, 07 Aug 2001 13:48:38

Joe,

You can get 102 mm cranks from Unicyclesource that will give you more clearance.
Many freestyle riders in Japan ride with 98 mm cranks. These would be even
better. A few weeks back Andy  Cotter posted a link to a japanese site where you
can buy 98's. I seem to remember that he bent the 127's he bought there, but I
doubt your 5 year old will have that problem.

John Hooten

Quote:

> My 5 yr old just started learning on a 12" sem which came with 4" cranks from
> unicycle.com.  (John - it's great).

> They lower pedal is 1/2 inch from the ground when the cranks are vertical,
> meaning, he can't lean right or left.  I think this is hindering him a bit in
> the learning process.

> For this wheel size and age, these cranks are LONG.  I can ride his 12" in a
> straight line, but to turn I cannot lean, but instead must do a standstill,
> then rotate my body along a vertical axis.  (Talk about circus clowns!) Of
> course for a beginner, this is impossible.

> When my son attempts to ride, a pedal will hit the ground and knock him off
> balance.    He doesn't want anyone holding his hands, he just wants to get on
> it and keep trying.  I'm sure his persistence will pay off, but I'm wondering
> if he might be better off with 3 or 3.5 inch cranks (assuming they are
> available).

> Anyone else out there have kids riding the 12" sem?

> Joe

 
 
 

Best crank size for 12" sem

Post by Gilb » Tue, 07 Aug 2001 14:55:08

102 mm are 4", which is what he already has. At the MYS site, they
sell both steel and aluminum 89 mm (3.5") cranks, which are their
shortest cranks.

That's at: http://www.mys-co.com/cgibin/cgibin/shop.cgi?gcode=928

  > You can get 102 mm cranks from Unicyclesource that will give you more
  > clearance.

--
Posted via the Unicyclist Community - http://unicyclist.com/forums