I’ve only read the first page so far, but I was planning on trying this setup when I get or build my MUni. Did I hear word of 40mm ISIS bearings coming out soon or did I just dream that?
I was powering up some of those hills at RTL with 102s, so I don’t think I’ll have too much of a problem with 137 on a 24.
Finally someone sees the advantages to short cranks for downhill muni! I have been telling people that Short cranks are great for quite a long time but most people think I’m just nuts. I used 110’s on my 24" for a race once and I found that it made some things way easier.
I really want to get a brake so that I can really experience the full potential of a short crank build.
I have the option of sticking with 170s on my 24" or getting 140s. I think I’ll stick to 170’s because I don’t have the money to get a brake ATM and I think my riding suits long cranks anyway. But I agree that for downhills something shorter would be nice, even without the brake. It depends how fast you wanna go also. On real steep technical downhills 170s seem great because there’s just so much control.
I don’t think either shorter or longer cranks is correct answer. We are all experiments of one; that is we all have to figure out what set up works best for us. There are a lot of factors involved some of which include fitness, skill level and just the type of terrain one typically rides. Being a long distance runner it seemed natural to me to spin a lot and so I’ve had no trouble doing some long Muni rides i.e. well over 20 miles on my KH24 with 150mm cranks. The whole spinning pace is really like my running pace so it all works out. On the other hand I’ve been riding my 36er more and more this summer because it is too hot and oppressively humid here in Alabama. With the 36er I agree that the shorter cranks are the way to go. I know it is difficult to try lots of crank/wheel combinations because it can get expensive real quick! If you afford a better uni or munu with square taper crankset, like I started out with, then trying different crank setups is not nearly so expensive as trying all the different ISIS combinations!
James, Qu-ax is coming out with 89mm ISIS (acording to Rodger) no 40mm yet.
The last time I read one of these crank length threads was 3 or 4 years ago when I was trying to figure out what to build my MUni with. I decided to go with 170’s. I actually think it was back when Andrew Carter started riding and he had to start with shorter cranks than he had originally wanted.
After 12 months of seldom riding MUni, I have started riding again and in the last week have gone back to some technical MUNi.
My style has changed a lot from those early days. I now ride using less strength, but more efficiency.
After going down a mild descent today with the 170’s I was out of my seat and the crank length revolutions seemed huge. I do this because of knee issues, so out of saddle down hill helps out the knees. This ride today, really made me want to consider downsizing to a shorter crank, especially after reading this thread.
It makes me want to play around with the crank length with my parts bin and my old thrasher MUni with an old 4 taper Suzue hub. Hmmmmm.
Better yet, Kris could donate one of his 24" Munis with the 137 mm cranks with brake to a raffle for the upcoming California MUni weekend just to keep the discussion going.
At CMW Santa Barbara a few years ago, Tom Holub won the KH MUni with 150cranks. Last year in Santa Cruz at CMW, I had trouble climbing with 170’s and was blown away by Tom as he very efficiently climbed up past me on his 150’s as I walked along up the hill.
Cheers.
Although Tom is a pretty strong rider, so I’d guess he’d go past a lot of 170mm riders.
By the way, the knees thing - I know it isn’t the same for everyone, but I find I get way less knee hurty on short cranks. Especially on things like long not too steep descents, where you spin out, and the brake doesn’t get used much. Well worth having a play with. Assuming you have a brake already, which is the first thing to do for knees.
Joe
I just switched my trials 137mm to my muni.
Its faster and smoother i can tell already its going to be awesome on the trails.
I wonder if my balance on the skinnys will inprove.
since the cranks are a bit shorter
can wait to test it out
wes
You’ll have to pry my 170s from my stiff, broken knees. 
Important to keep in mind
There are two things to keep in mind when using shorter cranks that have not been stressed enough here.
Climbing steep hills with rocks, gravel, sand or just unsmooth surfaces is totaly different than climbing steep asphalt or even smothly packed dirt hills. You need to have much more “instant” control over the pedals. Longer cranks give you this. So depending upon the terrain you ride you might preffer longer or shorter cranks.
If you are doing steep downhill then the shorter the cranks the more you are going to depend upon good breaks.
Unicorn
Just got back from a couple of days of hard technical riding in Vancouver and Squamish. The first day was on my KH24 with 137’s and a brake. The 2nd day was on a borrowed KH24 with 165’s and no brake, so I had a good chance to compare the two. It was actually the first time in 2 years that I’ve ridden a 24" with longer than 150’s.
My impression is that there are some good reasons to use shorter cranks for all-around riding, mainly to do with smoothness. But specifically for technical downhill on rough, irregular terrain- I don’t think it’s easier. For me, I felt about the same in terms of comfort until I reach the limit of my ability to use the brake to replace the loss of torque with shorter cranks.
As terrain gets steeper, it felt like it took more and more concentration to have the same level of instant braking control with a brake, that you get with your feet. Beyond some steepness threshold, when I started to have to really work my way down a slope with drops to steep terrain and I wanted to instantly stop and where a fall might be uncomfortable, it felt really good to have the control of longer cranks.
It feels like it’s a good goal to try to get better at the brake until it can really replace foot-braking in all situations with shorter cranks, but for sure it is a learned skill.
Kris
well i tryed my 137’s on a start of a trail. 150 to 137 i felt a big differnce in the lost on torque. it even felt like little bit more work to ride on the flat trail. but went alot faster on the road of course.
well heres a little clip of riding 137,s i thought i was going to be awesome riding them but i still suck lol. I think the music went good.
i think i need more torque for the skinnys. its hard to get moving the problem might be because i weight to much too lol.
happy riding to all
wes
http://www.youtube.com/watch?v=Za_Rgu_CI_M
Hey Kris when are we going to see some new riding clips form you? any thing would be awesome!!!
Kris’s Imput
Kris your last post on this thread was really interesting. I would be interested in also hearing about your impressions for steep uphill climbs with both of the setups.
Thanks,
Unicorn
For uphill riding, I found that:
-Riding uphill on narrow logs can be easier with longer cranks, even though longer cranks can sometimes wobble more, because it is easier to balance when you aren’t pushing as hard and when you don’t necessarily have to reach down and hold the handle.
-I find long steep climbs as easy with 137’s as with longer cranks, but only since I got more used to pushing 110’s up a hill on a 36’er.
-Long, gentle to moderate climbs feel easier on the 137’s.
-Jumping and rotating the cranks 180 degrees in a tight spot to get back to your dominant foot position feels easier on 137’s.
-Seat-in-front hops are harder to land and take off from off-angle surfaces.
-Situations where you might hit your pedals are noticeably less.
Kris
Kris’ post above about comparing the 137s with the 165s agrees with my perceptions on this issue. What a lot of people have been leaving out of the equation in their posts is the brake part. The shorter the cranks, the more important a brake is for downhill control.
I have a Wilder, which cannot have a brake without a frame rebuild. So most of my MUni experience is brakeless. I started out with 170s, which provide a lot of leverage but reduced speed and increased pedal hits. Then I got a pair of 145s which made long rides much more enjoyable, but took away my confidence on anything technical downhill. They were too short to have fun with (without a brake) on my “strong” MUni. I have other MUnis that can be used for less-technical riding. So for Moab this year, I got a pair of 160s. Still a little long, but much more control on the technicals and steeps. Again, all of this is without a brake.
Also they worked well for me in the killer uphill race at Unicon where I medaled, even though I stopped to take a break without realizing I was less than 3 meters from the finish line!
So factor in the brake. Also, factor in the terrain people are talking about. This is really hard to compare if you haven’t seen where a person rides. I’ve been to the Vancouver North Shore and Santa Cruz (where stuff can be steep and crazy-hard). Also I’ve seen enough pictures of the LA-area trails to know they’re in a similar league. For people in other areas your trails might just not be as hard. Beyond that, there’s no accounting for taste. Do what works for you, but keep the experiences of others in mind as trying new things may open up new worlds for you.
Example: I borrowed a 36" unicycle to race at Unicon (Thanks Roger and John!). It had 125s on it, which about killed me in the 10k race, which was dead flat. I needed something shorter for the Marathon (42k). I had the opportunity to buy a pair of 102s for a reasonable price, and I did even though I’d never tried them on a 36. The Marathon course wasn’t quite as flat as the 10k, but all the hills were mellow. The 102s worked great! I got a silver medal in the “old guys” group with a time of 1:48 which really impressed me. Don’t be afraid to try new things.
Thanks for the input Kris and John
I really enjoyed reading the last posts very informative and they make sense.
Thanks. Also great to see that you are back to riding off road since your injury Kris!
Unicorn
Sorry to resurrect an old thread, but …
I swapped out my KH24’s 165s for a nice new set of 140s (it’s the 05-06 hub) earlier this week, and took my first muni ride on it today. I’ve been riding my KH29 with 150s for quite a while now (though I had some 165s on the 29er for a bit, too), and I wanted something on my 24 that felt closer to the way the 29er feels. I figured that 29er + 150s and 24/Gazz + 140 would be a decent match.
I gotta say, I really dig this setup. I was somewhat, but not horribly, slower than when I’m on the 29er, but not nearly as slow as I’d been with the 165s. I had noticeably less knee pain with the smaller circles. I could climb everything I could previously climb with the 165s (which may say more about the hills I climb than anything else); what I noticed was that when I had to stand up and torque hard, the wheel wanted to spin faster/roll more easily, and so with what felt like the same effort I climbed faster than before.
And here’s what I’m thinking, too. A lot of the time, on hills that are steep for me, I’m out of the saddle, pushing about as hard as I can go so that I maintain momentum. I guess I’m not so great at regulating when it’s at the edge of my limits. Anyway, what I’m finding is that if I have 165s on, a lot of that effort just goes to waste, because I could probably get by with less effort (if I had the skills). So with these shorter cranks on the muni, that effort is still expended at about the same level, but with results that are better (speedier, more stable, less wobble).
So I’m a convert. Anyone need some older KH/Onza 165 cranks?
More oldie but goodie thread resurrection:
I was looking over what Kris discussed in his 2008 thread, really interesting to see how some folks can run downhills on short cranks. It seems like crank choice has a lot more to do with style than what is best, so for those who favor speed and roll technical stuf fast, short cranks are more freindly to their needs.
Then there’s the folks who take a more “calculated” approach, slower, prefer control over speed, this is likely the group who leans toward longer cranks. It may be the same for folks (like Kris) who choose a narrower tire (<2.5) over a wide tires, choosing speed over shock absorption.
I’m defintely in the group preferring long crank/fat tire combos, never have felt like spin rate was all that much of a consideration for my riding as I can make a bigger crank spin just fine 
Check out this thread:
[THREAD]83122[/THREAD]
Note that most riders use a crank that is 150mm or longer.
Resurrected again! (why start a new thread?)
Just wanted to say that I finally made a configuration change on my KH24" geared unicycle (KH/Schlumpf Hub) and swapped my 150mm cranks for a pair of 137mm cranks. While I’ve only done one test ride (7.1 miles of mixed road/ technical trails in ~1 hour) , I’m convinced this is the way to go for me.
My observations:
Shifting:
I guess I must have been having a harder time shifting than I gave myself credit for using the 150mm! I’ve got small feet (men’s 8.5) and while I’d been fairly successful shifting, it would take several crank revolutions for a good shift. With the slightly smaller 137mm cranks, I was able to quickly up/down shift! Amazing! I can totally see myself being able to quickly up/down shift as the trail terrain dictates rather than reserving shifting for roads vs. trail.
In high gear:
In low gear:
Anyhow I love this new configuration and am sorry I haven’t tried it before! Overall the ride seems very similar to what I had on my 26" with 150mm cranks (until I sold that uni recently! ). While I’d love to be able to afford to upgrade to a geared KH26, it probably isn’t going to happen for a while, and why the rush? I like my KH24 set up and I just put on a brand new Nokian Gazzoloddi 24x3 tire so I’m good for a long time!
I’m also ridding 137mm on my 24" KH, but that’s mostly for street… But when I have tha chance for riding MUni (which is like only at the danish championships :P) I ride them too Before I sometimes rode 125 to get more speed, but it actually didn’t seem to be that good… For me 137mm is a oerfect length for 24" wheel (but I use 90mm if I’m riding tours on the road)