First impression of shorter cranks on 36er

OK, so I had my LBS guy swap the cranks on my Radial 360 from the stock (steel) 150s to some alum. alloy 125s (Quax from UDC). The reason I had him do it was I lacked the tool and know-how to do it myself. Now that he showed me how and sold me the tool, I’ll be doing it myself from now on.


I took the 36er for a quick trip around the block when I got home (it’s dark and I haven’t had time for a proper ride.) This was my first time riding anything with less than 150s, and may I just say -

I am superhuman! I’m Spaceman Spiff! I own the universe! Wow. With barely a twitch I can break the sound barrier.

I got home 10 minutes before I left! It’s truly amazing the difference these make!!


I went from a friend’s 24" DX with 150s to a 29er with 125s, so I had a similar experience, but gained more speed. Quite the feeling, as he said :smiley:

my experience is with shorter cranks, you have plenty of power for accelerating and climbing; the loss of torque is not a problem for these situations. however, when stopping or slowing down, shorter cranks make it MUCH harder.

It seems that the change in power should be symmetric, but for me it wasn’t at all. In my opinion, the ideal setup would be the shortest cranks you can find and a brake.

So true, when I bought my coker it came with 150mm cranks. It was my first time ever owning cranks larger than 125mm and it felt sooooo slow. I actualy felt it was a bit slower than my 29er with 125mm cranks because my legs had to move so far. The second I got home I tossed on some 125 mm cranks from another unicycle I wasn’t using anymore and the difference was awesome. I now love my coker despite its weight although I can’t wait to someday get an airfoil rim and SS spokes.

Howdy to all. Thought it was time to join in the fun after many months of reading and enjoying all the posts. Great group you’ve got here.

Funny you should go that route with shorter cranks, Steveyo, I just swapped out 125’s for 150’s on my 29’r this evening. Could use more torque on the big hills on muni rides. I just got in my Nimbus 36" last week and can’t see going shorter than the stock 150’s just yet, perhaps someday. A cautionary note: keep an eye on the aluminum cranks. I hear the potential for stripping them on a 36" is pretty high.

SWEETNESS this excites me a lot (: Because I have 150s on my coker, I’ve also tried it with 170s, but very soon (tonight) I’m going to buy 125s, and now, I’m EXCITED!!

I ride my friends coker with 110s. I couldnt imagine wanting anything longer than 114s.

I agree; I can get up the hills I need to on my 29er with 125s, but slowing down when flying down the same hills is difficult and feels very dangerous. I haven’t tried a brake on a uni, so I don’t know how that is.

All true…lots more speed opportunities. Pay closer attention to the road…it develops a Napoleon Syndrome. Little bumps trying to get all big and take you down.

I love riding my 36er with 127mm cranks. They suit my riding and my short legs. Not quite so easy on the uphill 3 miles that I ride but both times I’ve ridden up it on the shorter cranks the wind has been strong and against me so that has made it more difficult.

I just got back from my first 10-miler (10.77 miles according to my cycle computer) on my 36er with the new 125mm cranks. I’m still getting used to free-mounting the thing, as it’s a bit harder to get the wheel moving with less leverage. I did, however, make all the uphills, and I wasn’t sure I’d be able to with the shorter cranks.

In very windy conditions, my average speed was 10.55 mph even though a big chunk of the ride (the most wide open part) was against a stiff headwind which kept me below around 8 mph for about 3 miles. The with-the-wind portions were all on wooded, more sheltered roads so I didn’t get as much tailwind benefits.

I think if there was only moderate wind I could shoot for an average above 12 mph. Not god-like, I know, but I’ve never averaged 12 for an hour or more.

The most major difference I noticed is with the shorter cranks the higher speeds feel much more stable. With the 150s even 14 mph felt a bit scary and wobbly, but the 125s make 14 feel totally mellow and sustainable. To that end, without scaring myself too badly, I hit a new personal high speed of 17.52 mph during the ride! Woo-hoo!

:astonished: :astonished: :astonished:

OK, that does it. I’m putting shorter cranks on mine.

I’m glad your enjoying your new cranks. Your post regarding your quest for the perfect size crank inspired me to order a pair of 114mm Qu-ax 1’s myself. I haven’t installed them yet since I’ve been doing more Muni riding.

Something you may be interested in is an easy way to switch from one crank length to another. A company named Full Speed Ahead (FSA), as well as a couple other companies, sells a one-key release system for cranks. When installed, with nothing more than an allen wrench you can spin off one set of cranks and install another. Very cool! The only catch is that to keep this as simple and ‘tool-less’ as possible you’ll need a pair of pedals on each set of cranks. Check out your local bike shop for the part.

Can you find them online?

Re: new 114s
You’re gonna love’em.

Is this some space-time perturbation? Aren’t you going to write this tomorrow? Those must be fast cranks.

125’s for my coker were my favorite uni buy I’ve ever made.

(was or were?)


I wrote it today, but I didn’t do the ride until two days from now, next Thursday.

how fast are you guys pedaling? I can easily turn 105rpm on my bicycle for an hour or more. On the uni, I’m much slower.

I have 125s on my 29er (well, 28er) and I’ve hit over 180 rpm, which took me to 15.2 mph.

Distance of this ride: 10.77 miles = 682,387 inches
Wheel rollout (approx) 110 inches
Number of wheel revs: 6203
RPM = 6203 revs/61 minutes = approx 101 rpm


The shorter cranks allow ones feet to move slower and in smaller circles, and so it’s easier to maintain high rpms, if the power is there. On flat or downhill, no problem. Uphill or upwind, a bit slower, no doubt.

During my brief moment at 17.52 mph: 168 rpm, but literally for only a second or two. With longer cranks, the pedal speed can literally throw ones feet off the pedals, but since the pedals are closer to the center of rotation, the pedals are travelling around more slowly (same rpm, just closer to the center). Of course, I was concentrating on only one thing at that moment, and that was NOT coming off the pedals.