Schlumpf hubs: general discussion.

you can also make a shift engage in that situation by using the brake (as long as its a rim brake). Apply it, then take the load out of your legs and the hub will then engage the shift. Learning to shift in all sorts of different terrains and situations is one of the challenging joys of riding a guni.


I understand the not shifting under load concept, hence I did what I did to shift it. My legs were probably lacking feeling from the cold and fatigue. I rode up the mountain for about 30 km in fairly cold weather (for Australia). I got to ride through the snow for a bit at the top before heading back down. Good practice for the upcoming snow ride here in Victoria next month. Hope to see you there Mark.

Fill me in on this snow ride as well, sounds interesting.

Did someone say snow ride? Details here

We should have something up on the front page of soon.

What a difference crank length makes. The last few weeks I’ve been tired while while riding. I’m thinking, “what the heck is wrong with me?” I’ve mostly been riding the Nimbus Oregon or my 2-speed. So today I’m riding the Schlumpf up a road that is not super steep, but it’s constant climbing for about 3 miles. 2/3 of the way up I get off pretty tired and swap my pedals to the 137s. I’ve been using 165s on this and the Nimbus. It’s amazing how much easier it was to finish the climb. The test came with high gear on the downhill using the 137s. It was a little weird at first but soon became very fun. When I got home I practiced shifting without the tumor-like creation stuck to my ankle because my feet could reach the buttons, and the ride was much smoother. I’m almost to the point where I can say I love this thing. It takes a lot more effort to shift to low gear. I don’t know why it’s harder to hit that button. I’m looking forward to tomorrow’s commute to school.

FS: 2011 Schlump ISIS Hub, NEW

I have a Schlump ISIS hub on order from Silva Cycles.

I ordered it in May 2011, it is currently in production, rumored to be ready for shipping.

If you are looking to buy a Schlump hub, this would be the fast track to getting one.

See thread here, send PM for details:

Here’s a comment FYI on riding the KH/Schlumpf hub in mud, and the shifter button, based on some experience with it:

If you ride a lot in mud/wet conditions, it’s possible for the hole in the shifter button to get clogged with mud. If you then push your allen key into the hole to loosen the set screw and remove the button, mud gets jammed at the bottom of the hex hole, increasing the chance of jamming/stripping the hex.

On a ride you can usually loosen the bolt by first cleaning the hole out with a very small hex but this still can still result in accumulation of packed mud at the bottom of the small hex hole.

Once home and perhaps also for regular maintenance, it’s a good idea to take the screw entirely out of the shifter button and remove any packed dirt. A safety pin + some WD40 works great.

If you ride regularly in mud, a commercially made plug for the hole or a second set screw threaded just flush with the face of the hole might be a good idea.


I have had to use the safety pin trick a couple of times which works quite well. I was wondering what I could use to plug the hole but still leave it easy to access, but decided I didn’t really need anything, so have left it as is.

Also, if backing out the screw is impaired by mud in the threads, just screw it the other direction, out the bottom, and clean the threads once it’s out.

After Klaas Bil noted in this post that action of the Schlumpf lever arm pressing forward on the frame could affect the ride feel, I started trying to pay attention to this possibility. This weekend I did a fairly epic ride on my Schlumpf 29er (four hours of mixed road and dirt, with steep climbs and descents, almost non-stop) which allowed me to try it out on a bunch of different terrain.

The result is that I notice the effect when my weight isn’t on the saddle. When I’m cruising in high gear sitting down, I don’t notice it at all. When I’m moving fairly quickly but am out of the saddle to get over a small rise, I notice it a little. When I’ve slowed down a lot and am trying to power over a hill without downshifting, I notice it a lot; I really have to fight the movement of the frame. This explains a number of UPDs I’ve had over the years in that situation, and why it seems so much harder than riding a Coker up the same climbs. (The gear is higher than a Coker, but the difficulty is greater than the difference in gearing).

I think it also explains why starting up in high gear seems more difficult than it should be; in addition to having to push the higher gear, you have to fight the uni’s tendency to push you forward of your balance point.

Yes - I think this is a noticeable effect at first, especially when accelerating from a slow speed while standing up. However, I also think it pretty much goes away once you become accustomed to the more vertically downwards pressure you have to place on the pedals while accelerating in 2nd gear, compared to first.

Tom - that sounds like a great ride!


It is pretty much the ride for which I built up the geared 29er. My house is about 6km from the bottom of the trail system; too long to think about riding there and back on a real MUni, but fine for the geared 29. Once I get there I can do some real MUni. This weekend’s route included the downhill race course from U Games, among other nice singletrack, and a climb that was rejected as the uphill race for U Games because it was too difficult. Looks like it was about 40km, about 400m of elevation differential from low to high point, perhaps 800m of total climbing, although I didn’t have a GPS.

Somewhat along the lines of Kris’s answer, I think you have to be a novice at Schlumpf riding to fully notice the effect. Once you’re more proficient, you correct for it automatically, and it becomes difficult to single out the effect from the other reactions that a unicycle has. Still, for me, a non-geared unicycle feels more “quiet” or “neutral” than a geared one.

I agree with this. Even though I now ride the geared uni with more confidence, it’s still a different kind of workout. It’s also mentally challenging the way my non-geared unis were when I was new. I like this additional challenge.

new stuff arrived

are they marvelous?

I have two hubs on the way as well :sunglasses:

You’re not building a bike, are you? :wink:

Or a 4 speed?

Another effect I just realized; this is probably why using the brake in high gear is so much more difficult. As your pedal pressure moves forward and back, the frame will want to move forward and back with it, which is what causes the feeling of back and forth over-compensation that I often experience.

Yes, I have experienced this effect a lot as well. It is particularily strong when going down a long slope on the geared 36er (in high gear) at high speeds when you have to worry a lot about the forces introduced by the brakes versus the forces introduced by the gearing when breaking by foot. It can get very hard not to lose control and feels pretty scary. Did that make any sense?