[Schlumpf Questions] Crank Length

Sorry for the multiple posts on related subjects, but I figured people using the search facility in the future might find things easier.

This is a question for Schlumpf owners only really, as normal crank length theory doesn’t always follow with these things. But what length of crank do you find works best for you (and what wheel size do you use?), and why?

My 29" Schlumpf came with 150mm cranks, and I find these very long and unweildly in low gear, but generally about right in high gear. On my everyday 29er I have 110s, and I used 125s on my 36". If I was to change to, say, 140s, is there a particular type you’d recommend with regard to Q-factor (so I can still click the button) and button-end thickness? Or any that you know don’t work?


Qu-ax 125s work, Tony Melton has them on his. I’ve got prowheel 150s on mine. I’ve got some 125s (that I’m raring to put on but can’t damn it), which I think are official schlumpf ones.

I think, but I might be wrong, that you’re not supposed to put steel cranks on the hub.

There are also official schlumpf aluminium ones available in most lengths, although I think they’re just rebadged cheap aluminium cranks, (one of mine snapped while I was just riding along), probably not worth paying extra money for.


I liked the 150s that Roger Davies has on his Schlumpf 36". I consider that the minimum size I would feel comfortable with in the high gear (54" equivalent). Maybe I could get used to 140mm in time, but I don’t think it would be very safe, especially on hills!