What crank length for 36er?

I use 137s on my geared 36. If I was ungeared, I’d use 125s. I find 150s to be too big if I’m looking for speed (and I’m dreadfully slow anyway).

I used 137s for the first seven months of owning my 36. Since then (four months ago) I switched to 127s. I ride almost exclusively on the road.

The 137s were pretty good but I find the 127s much more comfortable for long distance spinning. My average speed has increased too, but it’s hard to say whether that’s because of the cranks or just experience. It does depend what kind of riding you do though. Since you mentioned using 100mm cranks I’m guessing you’re riding on the road.

I don’t notice much difference in control between 127s and 137s for road riding. I do find mounting with the 127s a bit frustrating sometimes, particularly partway through a long ride when I’m getting tired. The 137s were significantly easier to mount with. Again, if you’re already used to short cranks then that probably won’t be a problem for you.

At one point I experimented with 117s for about a week, but struggled a lot with mounting and so switched back to longer cranks (for now).

A few months back I tried removing my handlebar and using 150mm cranks. Mounting was very easy and I had greatly increased confidence on rough ground. I wouldn’t want to ride 150s on the road though.

There are days when I dream about a Schlumpf 36er with 150mm cranks - easy mounting, fast on the road and usable offroad too. That’s probably not going to happen for a while though, if at all.

A bit off topic, but i have a 36" and ride it with 100 mm on the flat and 127-150 mm on hills. I do not have a 29" but often wondered if this would have been a better choice for hills or off road. Perhaps a 29" is more manageable. I do have a 26" for muni but find that this is on the small side for combined road-muni stuff.

I have a 29er as my primary muni and ride it primarily on singletrack, but also in the rough stuff. 140s on the 29er are really good and allow you to tackle technical terrain, but it’s also really fun on 125s to fly though sections and keep up with bikes. A couple of features I can’t tackle yet with the short cranks, so I usually stick with 140s. I ride 125s on the 36 because I can still get up those 17% grades, and it’s still quick enough to cruise distances. The 110s are massive fun, and very fast, but 125s suit my needs quite well for commuting and adventuring around town.

I haven’t gotten the opportunity yet, but after riding the 32 a little on-road, I think it would be a great singletrack wheel. I have yet to get out on the trail with it. It IS technically my fiance’s road wheel. O:-)

I bought my 36er with 145mm cranks, and almost immediately put 125mm’s on it - the 145’s felt far too long and gangly. I’ve stuck with 125 since - I’ve not found a hill I can’t climb with them and I don’t really do 36er muni. I’ve considered going shorter but to be honest the 125’s feel absolutely fine.

I’m only just getting into the big wheel thing, so I have 165s on my Oracle for now. I commuted to work on it the other night and was surprised how long it took, 9 miles was just under an hour. If I’m doing that again I think I will have to swap out to shorter cranks, either the 137s or maybe 150s as an in-between step.

Thanks for the input everybody!

What’s wrong with 90mm? they seam really nice to me. :wink:

I reckon I probably couldn’t even push a 36er wheel round with 90mm cranks, and even if I could, any hills would just have to be walked. They obviously work amazingly for you though, Mr. 18mph average over 40-something miles at the 100-mile record attempt :smiley:

How did you get into running such short cranks though? Did you just stick at 125/137mm like the rest of us, then decide to go for a huge jump? Or did you work your way down through the sizes until you stopped being able to turn the wheel?

The forces involved are not that different from riding a bike. The problem is balance and that just comes with time.