Crank Length on a Trials Muni



A

Allen Wittman

Guest
I've pretty much decided that I'm going to order a KH 24" once
unicycle.com restocks. I want to get into trials and (to a lesser
extent) muni, while having something fast enough to use for everyday
travel. If I wasn't planning on doing heavy trials, I'd just invest in
several, "weaker" unis--one for light trials, one for commuting, etc.
However, since this is the case, I think I'd rather spend the extra
dough to get something that I won't destroy anytime soon.

Anyway, as you all know, I have two choices in crank length: 140 and 170
mm. I live in Illinois, so the muni prospects are pretty sad and, since
I can't really afford another unicycle, I'd like to have something
that's at least a little quick for commuting around campus. I really
wish I didn't have to make this choice. I really, really wish I could
just afford a top-of-the-line unicycle for each and every occasion.
I'll keep wishing and you all can read on...

I guess the real question is, "do you guys think 140 mm cranks will be
good for keeping a 24" wheel under control when doing trials, or do you
think that I should go for the 170s and just deal with a slower
commute?"

Vote in the poll or leave your thoughts here or both. Also, any
suggestions on other equipment options will be appreciated.

Thanks in advance.

Also, while you're all here, have any of you heard about new options as
far as KH crank lengths go? I read a post Kris made back in June (I
think) about working on 155s or something, but I never saw anything else
about it. I tried e-mailing him with no response. I think I'll try
that again too.


--
Allen Wittman - Funny Like A Funeral
------------------------------------------------------------------------
Allen Wittman's Profile: http://www.unicyclist.com/profile/5171
View this thread: http://www.unicyclist.com/thread/31548
 
I just don't like 170s they are much too long for my taste. It seems
that commuting and trials are the main things this uni is going to be
used for, and as such 140s should work well. There might be some times
you wish you had a bit more torque, but if you get the 170s there will
be many more times you wished you had more speed.

But you don't have to listen to me.
Daniel


--
daino149 - How's it going, Texas?

there ain't enough body armor in the country for me to try that. -- Ken
on the mtbr forum in reference to MUni
------------------------------------------------------------------------
daino149's Profile: http://www.unicyclist.com/profile/933
View this thread: http://www.unicyclist.com/thread/31548
 
I like the longer cranks. Its ashame you can't pick something in
between. I have 160's on my muni, which I use mainly for trials. they
provide decent torque, and are helpful while Muni-ing. Sure I'm a little
slower, but i can just leave 2 minutes earlier or whatever. It doesn't
work out to be that much of a speed difference in my opinion. I tried
Frank from HOW's 135's on a 24 and the speed was there but not much
more. I don't think the tradeoff of speed for control is worth it.

You may run into problems when doing trials with the wheel rolling too
much. Then again, you may not. But I recommend the 170's. Or see if you
can try someone's out first.


--
TheObieOne3226 - Extreme Halfb*ker

Yeah. Shut up kid!

-The Thnikkaman
------------------------------------------------------------------------
TheObieOne3226's Profile: http://www.unicyclist.com/profile/4851
View this thread: http://www.unicyclist.com/thread/31548
 
I guess I'm going to end up having to go with the 170s.

Working with the physics of everything, it seems that 140s on a 24"
would require more than 44% more force than on a 20" with the same
cranks. While I was hoping 140s might be overkill for a 20" trials uni,
140s on a 24" are comparable to 97s on a 20", so I really don't think
those will fly at all.

170s, on the other hand are at least 18.6% more force, which is about
equivalent to 118 mm cranks on a 20" wheel.

I suppose the real moral is to not do trials on a 24" and that I'm an
idiot for wanting to do it.

Also, if someone wants to critique my calculations, please do. I just
simply used the relation of the radius to the moment of inertia of the
wheel. I completely ignored the effects of the wheel gaining mass or
becoming more "hooplike" as the rim and tire get heavier with larger
radius, thus driving the moment of inertia up even more.

Even so, I'm going to see if any of my friends have some shorter cranks
on their 24s and feel things out for myself. My brain hurts.


--
Allen Wittman - Funny Like A Funeral
------------------------------------------------------------------------
Allen Wittman's Profile: http://www.unicyclist.com/profile/5171
View this thread: http://www.unicyclist.com/thread/31548
 
Wrong. Doing trials on a 24" works great. as long as you've never been
spoiled by doing the same trials on a 19". Sure, you may not be able to
just quite as high, or as long (due to the extra wieght, getting tired
and all), and if you're just out thre for the fun. With 170's a 24" has
more than enough leverage to keep the wheel in place. I cant say I'v
ever used 140's on mine, but for trials I rode strictly my 24" with
170's for over a year, almost two infact. I dont think I ever had any
less fun than if I had a 19. If anything I had more, becuase I found it
easier to ride to a given riding location with the 24. And even with
170's I found it to be faster than walking.

However, now I'v fallen victum to having enough money for a second cycle
for trials. Sure it's nice, but I woudlnt say I necisarily have more fun
on it.

Goodluck with whatever you end up getting.


--
Max_Dingemans - Hey Look, who's that?

BLAH!
------------------------------------------------------------------------
Max_Dingemans's Profile: http://www.unicyclist.com/profile/1981
View this thread: http://www.unicyclist.com/thread/31548
 
Max_Dingemans wrote:
> *Wrong.*


I guess I was being a bit dramatic when I said I'd be an idiot to do it.
The point I was trying to make was that, for strict trials, a 20" (or
smaller) tire would almost definitely be a better choice, given the lost
mechanical advantage and extra weight that comes with a bigger wheel.

And, as you said, I'm making the choice to go 24" because of the speed
that I travel at right now on my 20". I'd much rather sacrifice a bit
of maneuverability for more speed.


--
Allen Wittman - Funny Like A Funeral
------------------------------------------------------------------------
Allen Wittman's Profile: http://www.unicyclist.com/profile/5171
View this thread: http://www.unicyclist.com/thread/31548
 
On Sun, 4 Apr 2004 21:25:39 -0500, "Allen Wittman" wrote:

>Working with the physics of everything, it seems that 140s on a 24"
>would require more than 44% more force than on a 20" with the same
>cranks. While I was hoping 140s might be overkill for a 20" trials uni,
>140s on a 24" are comparable to 97s on a 20", so I really don't think
>those will fly at all.

I have no expert advice for trials crank length, but it seems you have
your calculation wrong. The difference between 24" and 20" is not that
dramatic. 140's on a 24 require 20% more force than on a 20". They are
comparable to 117 mm on a 20" which doesn't seem too bad (although
shortish).

Klaas Bil - Newsgroup Addict
--
I think profile should make some stronger 145mm cranks - Ryan Atkins
 
I have one 170's they are fine not as fast as 145 but i feel much more
in control plus on steep down hills ur legs are not spinning like a
chicken's wings when it's tryin 2 fly.
Ben


--
thinuniking - muni person.(muddy)

My girlfriend's mum calls me circus boy!
------------------------------------------------------------------------
thinuniking's Profile: http://www.unicyclist.com/profile/4294
View this thread: http://www.unicyclist.com/thread/31548
 
I myself would get the 170s, but then again, I commute 2.1 miles to
school each day on an Onza 19" with 140mm cranks. You'll want the 170s
for both muni and trials. When doing any natural trials, you won't be
able to hop seat out on slight slopes because your foot pressure will be
too imbalanced if you do trials on the 140s. Also, it's a biznatch to
stop a muni on a hill while rolling 140s. Theys tend to kill technical
downhills, and force you to fly through them and hope you don't crash. I
used to ride 158s, and I found myself wishing for 170s many times.

But now, I've finally found a profile wheel for sale, and I'm able to
convert my current muni wheel into a nice light duty fireball equipped
street/trials/commuter uni. I also hear the fireball's great for
gliding. i have a 19incher, so the trials on my 24 will be just light
stuff that I do for kicks on the commute home.


--
gerblefranklin - Trials Unicyclist

Don't you think it's a cruel irony that acting like a G.I. Joe in the
army can get you a Medal, while playing with one can get you thrown out?
------------------------------------------------------------------------
gerblefranklin's Profile: http://www.unicyclist.com/profile/4295
View this thread: http://www.unicyclist.com/thread/31548
 
The subject line is misleading. You want crank length advice for Trials,
but it's a KH24 and you plan to also ride distances on it. Considering
the wheel size (and weight), the 140s are probably too short. They're
great for cruising and getting you from A to B, but will be pretty weak
for any hard cranking.

I used 140s for years on my "regular" 24" wheels when I rode trails with
them. In other words, 24 x 1.75. A 3" tire on a 24" wheel is essentially
a 26" wheel, so those cranks will probably be too short to have any fun
on rough terrain, especially when added to the weight of a Gazz or
similar tire.


--
johnfoss - Home of the Garage Page

John Foss, the Uni-Cyclone
"jfoss" at "unicycling.com"
www.unicycling.com

"Hey, could I have some of that spinach? I need to get this pork rind
taste out of my mouth." -- Ryan Atkins to Kris Holm, on the way back
from Moab after sampling some of my pork rinds. They grossed out the
whole van!
------------------------------------------------------------------------
johnfoss's Profile: http://www.unicyclist.com/profile/832
View this thread: http://www.unicyclist.com/thread/31548
 
You must log in or register to reply here.
Top Bottom Back