switching long cranks

Unicycles and Equipment
1

I’ve noticed that on a lot of the impressive vid clips I’ve downloaded e.g. Kris Holm and gbarnes’ stair one, the Muni’s have long cranks(I’m not sure if they’re 170mm or 175mm)

Currently I’m using 150’s on a 24x3" which I’m happy with as they’re good for getting a decent speed with; but I’m getting the urge to try some 175’s to see how much better control I can get.

I was wondering, how feasible is it to be switching the cranks on a regular basis i.e. to get my left crank stable on a new fitting has always involved grease, hammering and constant tightening over several days to get it stable.

2

I’m actually using 150’s on a 24x3" in the video you mentioned. That said, I’m in the process of building a new 24x3" with 170 mm profile cranks.

About your question, I personally can’t get excited about changing square taper cranks on a regular basis. I think you might find that when you go to 170s you won’t go back to 150s, but I have no real experience here. While I’m talking about stuff I have no experience with, 175 sounds pretty long on a 24x3", I’d stay with 170 or less.

3

Have you got a link you could give me for this video? I don’t think I’ve got it.

Thanks,
Andrew

4

http://www.unicyclist.com/gallery/isu_stairs

5

I wouldn’t switch cranks regularly on a standard square taper hub. It’s just too difficult to get the cranks tight again after changing them. If you’re using a square taper hub it would be best to just get two wheels (one wheel with short cranks and one wheel with long cranks) and swap wheels instead of cranks.

If you have splined cranks like Profile then swapping cranks would be OK. It’s easy to get splined cranks tight again so swapping cranks would be less error prone.

The 170mm crank length got to be the standard by the California muni guys and other early west coast muni riders (like George Peck and Kris Holm) who ride in steep terrain. If you have ever been on the trails around Santa Cruz you’ll understand why the preference is for long cranks. If your trails aren’t steep and technical like Santa Cruz then shorter cranks might be better. It also depends on the style of your riding. Some people have a style where they just keep on spinning the cranks no matter what and shorter cranks are better for them. Other people have a style that is more suited to long cranks. It all depends on your terrain and your style of riding.

I ride with 170’s on my 24x3 muni because that crank length suits my riding style and my local terrain. But I’m getting a second wheel built up for my muni that is going to have 160’s so I can play with some slightly shorter cranks.

6

Re: switching long cranks

In article <onewheeldave.n1kto@timelimit.unicyclist.com>,
onewheeldave <onewheeldave.n1kto@timelimit.unicyclist.com> wrote:
)
)I’ve noticed that on a lot of the impressive vid clips I’ve downloaded
)e.g. Kris Holm and gbarnes’ stair one, the Muni’s have long cranks(I’m
)not sure if they’re 170mm or 175mm)

Most are 170mm. I would not go with 175mm–even at 170mm I get pedal
hits causing UPD’s.
-Tom

7

I know that many people would disagree with me, and you should also bear in mind I’m small and light (5’7" approx. and about 140 - 145 pounds), but…

I have experimented with various cranks and wheel sizes: cranks from 89mm to 170mm, and wheels from 20 - 28 and Coker. I’ve ridden many of these combinations ‘off road’.

Personally, I find 170s are no fun at all.

They are excellent for lowering you down a steep hill without losing control or popping your knees.

They are OK for slogging up a smooth but steep hill.

They are appreciably slower than 150s, and steering is less precise. On obstacles, what you gain in ‘max torque’, you often lose in momentum.

Think of engines and gears. changing the length of the cranks is not simply the same as changing gears, becasue it is actually changing the characteristics of the ‘engine’. Each rider has a best crank length for speed, a best crank length for torque, and a best crank length for general use. If you go far outside this range, you just make your engine less efficient.

Better, then, to tune the engine with the RIGHT length of crank, then adjust the gearing by choosing an appropriate wheel size.

For me (a skinny midget, I’ll grant you, but with a certain puckish charm) I’d far rather ride all day on a 24 with 150s than a 26 with 170s, even though the 2he ratios are broadly the same, and the bigger wheel has more ‘stomp’.

Put it his way: I gave my 170s away to a stranger, I hated them that much. (the 170s, not the stranger.)

8

Yeah I think thats a good point, I do feel that I have a lot of control with the 150’s and that I can go as fast as I need to do.

It’s good to know that the stairs were done with 150’s; today I rode into town to have a go on the town hall steps- they’re very well designed cos they get wider towards the bottom. This means that you can roll onto them at any point i.e. onto a bit with one step, then a bit with three steps etc and build up to the whole thing.

I’m still on two and a half, and I think it could be some time b4 I’m diong the whole lot.

9

I’m running 160s and they work at wonderfully for MUni and trials.