I’d really like a set of splined 150mm cranks for my 24" MUni. I reckon this is the perfect length for a 24" muni - fast enough for cross country riding but long enough for control on stunts and drops. At the moment the DM ATU crankset seems the only option, and an expensive one. It appears that Profile doesn’t make 150mm cranks, leaving me with shorter and longer choices.
There are 145mm Profiles and 140mm Onzas and KHs which would be too short, I reckon. On the longer side there are 160mm Profiles and 165mm Onzas. I plan on riding stunts and doing reasonable sized drops so I don’t think 145s or 140s would afford enough leverage/control to land these easily. On the other hand 160s or 165s would, but they’d be painfully slow for general trail riding.
I guess what I’d like to know is does anyone ride fairly hardcore offroad including drops and structures on a 24x3" with 145mm Profile cranks? Is this length OK for such riding?
This is really a job for Mike Fule, however I’ll give it a go.
Like you Ithink 150mm is a nice compromise for muni.
Mathematically speaking 145’s are a mere 1/30 shorter than 150’s, I really can’t imagine you’ll feel much difference.
I’ve found going from 150’s on a 24" to 125’s on a 29-er to be a big difference. however that’s a change in both crank length and wheel size. Putting 125’s instead of 150’s on my muni was easy to get used to, it meant less control but then again it’s a 1/5 change.
Lets assume however that the 1/30 shortening is significant; in that case you should still go with the 145’s as the other option- 160’s is a 1/15 increase i.e. twice as large a difference as the 145’s.
Wow, that’s amazing…people know my muni setup! Tony, you’ve ridden my muni. Did you really find it all that different to your muni with 152’s (or whatever they were)? I’ve done biggish drops (like that one at Canberra) and didn’t even think about my crank length…it just wasn’t an issue for me. In fact, you did that drop and the bigger one. I find my muni pretty good for hill climbing as well because you keep your momentum and generally ride in a smoother fashion. I think you should go for 145’s. I honestly think that it’s the perfect setup (at least for me) with the brake the I will soon have (yes!). I think if the crank length is not an issue when descending No. 9 without a brake then it’s a good length.
I agree with Andrew. The shorter cranks definitely make for a smoother ride, and the momentum is awesome for getting up steep hills. Not only do you climb up stuff that is just as steep, but you get up there faster. There are only a few occasions on which I would prefer to have a few more millimeters than 145mm, but mostly a brake would do instead, for steep downhills. On landing big drops longer cranks might help, you really need to try for yourself. Come down to New Plymouth Tony, and you can have a go at some big drops with 145mm cranks, as soon as I get my MUni back from the damn police who hijacked it and are holding it for ransom (for a second time). If I’d have known you wanted to experiment with them you could’ve tried during the Juggling Festival weekend.
In simple terms of arithmetic, some of these differences are negligible.
If you take 150 as a ‘bench mark’ then:
145mm = 3.3% shorter
140mm = 6.7% shorter
160mm = 6.7% longer.
Of course, the difference between the shortest and longest on your list is significant: 160mm is 20mm longer than 140. 160mm is around 14% longer than 140mm.
So, if your ideal would be around 150mm, you will be choosing between very slightly shorter and faster, or very slightly longer and torquier. It’s a fine tuning thing, and there will be few circumstances in which you really notice the distance.
The longer cranks will give you a touch more torque when slogging up hills, or when doing slow and controlled descents. The shorter cranks will give you a touch more speed, so you will be able to rush short slopes.
Longer cranks might be slightly more likely to snap or bend on a drop because of the longer leverage. I have no experience of drops.
The maths isn’t everything, though. There’s an ergonomic factor to consider: what size fits your legs best? I know many MUniists like 170mm cranks. I just couldn’t get on with them, and I’d rather use 150s and walk a bit more.
Whatever size you buy between 140 and 160 will feel like the “right” size as soon as you’ve used them for a while. Remember that every unicycle is a compromise. Part of the fun is getting the compromise right; part of the fun is making the most of it.
You’re right, Mike, it is a compromise choosing crank length. I guess if I get Profiles I’ll be able to swap them with the 145s on my trials uni, and changing crank length won’t be a big deal.
Andrew, you’re probably right too. You seemed to do No 9 without probs (without a brake either) so 145s will probably be fine. I could get 160s, try em out then swap to 145s just to see what they’re like…
I actually planned on getting both 145mm and 170mm cranks (I didn’t know 160’s were available at the time) for my muni to be able to change them when I needed…at one stage. Now I personally don’t want longer cranks but of course it is all subjective.
As soon as I get my brake I’m heading to ‘Jelly Baby’ to do that steep bit again, then to that one fell off on (that I got on video) in the picnic area, then a new track that you unfortunately missed. Gecko and I rode this new track and almost made it cleanly down a really steep bit but it was combined with heaps of ruts…plus it was raining!
I’ve attached a picture of two of the main things I can’t wait to try out with a brake. I want to try to pick some of the other lines to the left and right of you in the top one and you haven’t see nthe bottom place but it will be great fun.
I know that’s no really related too much to your thread and I’m sorry, but I just started thinking about how good my muni will soon be and I got carried away…you know how it is.
