Kris Holm 36" Schlumpf, 165mm Cranks & Magura Hydraulic Rim Brakes

I have not used KH cranks with my Schlumpf. Also, I initially installed my Schlumpf into a 19" trials unicycle. Between a riding style that involved pivoting, the narrow cranks, and my tendency to hug the cranks with my feet, I was getting tons of accidental shifts as a beginner. Also, I attempted many shifts when I was barely moving, causing a pretty ugly freewheeling result. But, for anyone using the recommended KH cranks, those problems probably won’t happen.

Both. It’s really not that hard to shift unintentionally on either one. I’ve figured out ways to avoid it. If my speed and balance is within an adaptable cadence I’ll usually salvage the shift without a upd or dismount.

Once I mastered smooth short crank shifts, when riding longer crank my shifting is more jerky. For me, force/leverage/foot travel distance are harder to anticipate as crank length increases above 137mm.

Instead of pushing through the upshift I’ll switch to pausing in the upshift.

For me, if I have the strength necessary, all the crank length/gear ratio charts are just theoretical garbage. Just learn the skills to ride at any speed, stand on the pedals when necessary and get with it. Let heart rate and fitness govern your speed.


I have so much trouble shifting it intentionally it’s hard for me imagine switching it accidently. As for speed, fitness isn’t limiting my speed it’s mental for me. Going over 25km/hr on ungeared is very sketchy for me and I’m kind of intentionally limiting my speed on the guni to an extent for similar reasons. Now that I’ve had a fall on this one I’m going to be more cautious for a little while. I’m hoping with a more flexible handlebar that I’ll get this week will make it a bit more comfortable and manageable. I’ve had a few rides with the 150’s now and it feels much better then 165’s. As I’m pedaling much smoother in both ungeared and geared. I do have the option to go to 125mm but I think I’ll try 137mm if I feel 150’s are too long.

elpuebloUNIdo could you mount in high gear on a 19"? Is it viable or better off in low gear for mounting? Freewheeling sounds nasty especially if it happens at speed.

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I never put any time into learning to mount in high gear. The few times I tried it were awkward. And a few of those times, I reflexively hopped to maintain balance, sometimes causing an accidental downshift and a UPD. I use long cranks, and I am pretty heavy. I decided it is not a good thing to hop on my Schlumpf. I have a history of crank bolts getting loose on the Schlumpf, so I’m not going to be hopping on it.

I rationalized not learning to mount the G19 in high gear by telling myself it was a good thing to learn to shift. So, I mount in low gear, shift up, ride, shift down, then dismount.

I had a blast with the G19. Then I had a mishap. One of the tiny plugs holding the shift button got stripped (this is after I was so careful, using the torque tool to tighten it) and I damaged the unit trying to get it off. The hub was sent back to Florian for service, and when it returned, I put it into a 26" wheel. I am not comfortable riding at “full out” cadence / speed on the G26 in high gear. Maybe I’ll go back to the G19 one day.

I feel this thread needs an update. I’ve had my geared 36" for a year now and I feel I’ve made significant progress in that time. Since I first started I’ve progressed from 165mm cranks to 150mm which I used for over 10 months. Now I’m running 125mm for a little over a month now and I feel I’ve really started to make some real progress on these short cranks.

Initially it was a huge struggle to use high gear with short cranks and my heel position had also changed with the shorter cranks. Now my muscles have adapted to the shorter cranks as well as my shifting too. I’ve really been putting this unicycle through it’s paces on my daily commutes to work which are now almost 13km.

Just this week alone I’ve improved my times every day so far.


Today was my best run ever with an average moving speed of 18.5km/hr. Yesterday had my highest maximum speed ever at 33km/hr (20mph) which I managed on a downhill and on flats I can cruise at about 22km/hr. I’m much more comfortable then ever before riding at fast speeds where before I would feel very nervous.

It has also been a long time since I’ve had a serious UPD crash too so my confidence is higher then ever while riding lately.