Schlumpf shifting techniques

I have quite a few miles under my belt on my KH Schlumpf Nimbus 36, with 150mm cranks. I’m fairly proficient at shifting now; I usually up or downshift with one or two tries, and I (generally) don’t loose speed.

Speeds at which I shift:

  • I tend to upshift at 8-10 mph; I prefer shifting at 10 mph, and that is the usual threshold of when I decide I should shift.
  • I tend to downshift at 8 mph; sometimes at 10 mph
  • Up shifting at slower speeds is possible, but generally not efficient. It is more efficient for me to rapidly get up to speed (10 mph) in 1-1 and then shift.
  • Down shifting at higher speeds is possible (say 12 mph), but is sketchy since your go from a very low cadence to a very high cadence.

Hardware notes:

  • Anything longer than 150’s would be hard for me to shift; I’m short, and my feet aren’t physically large enough. Larger cranks would require me to ride on my toes. If you have trouble shifting with 165’s, well, drop the crank size.
  • I tend to ride more on the balls of my feet now. I used to ride with my ankle situated over the pedal (safer for muni), but having my feet back slightly more helps with shifting.

Shifting techniques:

  1. Slowly move your heel towards the button. I rotate my foot about a vertical axis that goes through the ball of my foot. It also helps to slightly lean your foot in towards the unicycle/crank at a slight angle.
  2. You should start to “feel” the button, and hear a consistent “click click click” every time your heel rubs on it. Just feel it. Don’t shift yet.
  3. Get a feel for the cadence and the rate at which your rotating by hearing the “click click click”.
  4. On the beat, move your heel in slightly more with a little force…and then you shift!

I don’t always do the two middle steps, but when initially learning to shift, I discovered this technique was very helpful. I do sometimes use this technique when I know a ways before I want to shift; that way my body has a feel for the cadence, and I can easily shift right when I want to.

Also noted: being able to 1-foot will aide in your shifting, as it generally takes a light foot to shift.


You shift pretty much the same way I do! I always try to avoid the two middle steps, but end up inadvertently doing them anyway, just because I can’t hit the button as fast as I’d like :slight_smile:

I’m not shifting as well as Corbin, and at lower speeds, but I’ve gotten to be maybe 90% successful on upshifts and 60% successful on downshifts. For me it has been helpful to move the ball of my foot further away from the hub, so my heel contacts the button at more of an angle. I also do better when I rotate my foot outwards a little, so the bottom of my shoe is contacting the button.

It also helps to anticipate the shift by leaning forwards or backwards; lean forwards to upshift, backwards to downshift. Nearly 100% of the time when I fail to stay up after a shift it’s because I came off the front on a downshift, or came off the back on an upshift.

Shifting is fun

My favorite down-shifting technique is to slow down almost to a standstill and then reach down, as my right knee goes down, and press the shift button with my hand. I’ve practiced this in a gym a lot and it works quite reliably there – it’s harder to get it right outside, but it does work, and it feels kind of flashy and cool!

I actually find myself avoiding shifting a lot of times. If I’m starting on the flat or on a slight downhill then I’ll happily start in high gear. I just have a 29" wheel which makes that more practical. Or, sometimes I’ll ride up to a stop light, stop, shift down while I’m not riding, take off with the traffic, and then shift up.

The other reason I don’t shift down while riding very often is that I accidentally downshifted once. That was painful. Now I have the downshift button positioned in a bit farther which makes downshifting with my foot a bit more difficult, but it’s a reasonable tradeoff for the piece of mind.

The main thing I like about my 29" Schlumpf is that it is easy to get on (lower seat than a Coker) while letting me ride faster. I also like that it is so versatile because I can use it for trials or even some modest trick riding when it is in 1:1 mode. I thought that shifting on the fly would be the coolest feature but, while it is very cool, it is almost as useful just being able to shift very easiliy when off of the unicycle. Curious.

That’s pretty neat, I wondered if that was feasible.

Shifting is expensive. I think in terms of total elapsed time, for most short hills I’m probably better off trying to blast up in high gear, and losing some time once I run out of steam, rather than trying to downshift at the bottom and upshift at the top. Right now I always try to mount in low gear and upshift, and downshift before dismounting, just to get the practice, but I’m sure that in the race I’ll just mount in high gear, assuming flat terrain. It’s easier to mount in high gear than it is to shift.

Other things I forgot to mention:

  • The hub tends to shift when only under a light load; if you are putting a heavy load on the hub, it won’t shift. You have to “let up” a little before it will shift.

  • When I shift, I “sometimes” stop rotating my feet (ie: let up completely), and let the gear kick in, and then continue rotating. This all happens really fast, but I realized it is something I started doing. At other times…I keep spinning, and the gear shifts at less predictable times.


I’ve been riding on dirt/gravel bike paths lately, and shifting is much harder there. It has a lot to do with what you (Corbin) wrote about shifting under ‘load,’ I think, as well as the whole smoothness and balance issues. It doesn’t help that I got new sneakers. I’ve always been much more successful shifting up rather than down, but my methods are different for both. I ‘kick’ my left foot inward at the right moment so that my heel hits the button on upshifting. I lean my right ankle in and pivot my foot so that my ankle bone area is hitting the button for downshifting. It’s not painful.

Here are a few of my observations on shifting after having the guni for a few months. Note that I think the combination of shoe-size and crank-size have a big impact on shifting, and I have rather small feet (us size 8).

When I ride with 125’s I find it easiest to shift with my ankle (not heel). I started doing as David suggested, with my ankle bone. This never got reliable for me, and started to hurt. I tried my toe (on the upshift) but again couldn’t get consistent. I then got some hightop riding shoes and - whala - no problemo. I simply angle my ankle in and it shifts. Love it.

For muni I’ve changed to 150’s and am having more trouble shifting. My ankle and toe don’t come anywhere close to the button. I can hit it with my heel, but I have to shift my feet so that my big toe is basically right next to the crank arm. Then I have to give it a wack with my heel, the harder the better, merely rubbing it against the button (click, click, click) rarely gets me a shift. Unlike Tom, I find I need to put my big toe very close to the crank, my foot isn’t long enough to put it further out on the petal to get a better angle on the button.

I’m not real happy with having to adjust my feet to shift on 150’s but guess I’ll just get used to it. Its well worth it.


I’ve only started riding my Sclumpf 29" again after 2 1/2yrs.

I can pretty much shift each time…but it sometimes takes me about 2-5 revolutions, and still haven’t been able to do it at speed.

My technique

  • shift my feet close into the cranks (until rubbing on crank)
    -rub/tap the button with my heel

I’m using 125mm schlumpf cranks with a taper.

Has anyone had trouble with accidental shifts? Especially with straight cranks? There’s not much room between your heel and the button- especially if you ride with your feet very close to the cranks like I do. I’d be a bit nervous about using straight cranks on a Sclumpf hub.


After the shift

I’ve been thinking about what happens after the shift lately. Occasionally when shifting down I’ll click the knob, the hub will shift into ‘neutral’ and I’ll fall off. After pondering this for a while I think I know what is happening. The hub is always supposed to shift into the next gear within 30 degrees. However that is 30 degrees of the pedals moving relative to the hub. So, if you shift gears and then continue pedaling forward at just the right speed, or if you fall forwards at just the right speed, then you may not get back into gear until it’s too late.

I think the risk of this is increased if you shift at very low speeds, which I do when gearing down. I’ve tried down-shifting at slightly higher speeds and that seems to help. I think the other thing to do is to try to apply a bit of backforce after hitting the knob, just enough so that when it slips into neutral there will be no problem with the hub spinning 30 degrees relative to the pedals.

I did a 121 mile ride on Saturday (part of the Seattle to Portland ride) with many shifts on the flat and on hills, and every one worked perfectly. I didn’t always hit the knob the first time, but once I did the shift was smooth. It was so much easier to get on in low gear and then up-shift. It was a huge improvement over three years ago when I had to try to leap up onto my Coker with tired legs. I do love my geared 29".

I did one once at speed. An accidental down-shift that left me on the ground before I knew what had happened. At least I think it was an accidental down-shift. I couldn’t think of any other explanation. After this happened I adjusted the down-shift knob in a bit more to be safe. Accidental up-shifts don’t worry – and they never seem to happen.

Occasionally when doing a sharp corner I will accidentally shift, I guess because my feet get off center when turning. This tends to be at lower speed so it isn’t as much of a danger, but I’m trying to be more careful now and it hasn’t happened for a while.

I’ve never had an accidental shift with the 2nd gen hub. I had one or two a few yrs ago on Hub 1.

I’d also be nervous with those straight cranks.

I have never had accidental shifts, but I am also paranoid about that. What I do is screw in the left button more than the right button, so that it is harder to downshift. If the button is closer to the crank and not a lot is sticking out, then the chance of an accidental shift is decreased. This does, however, make my downshifts less successfull on average, but missing every other downshift is a lot better than accidentally shifting at 20mph. Plus, with the geared 29, I hardly find myself shifting anyway.

I used to do the rub method by angling my foot in and letting it rub the button as I pedaled, but I find it less consistent than my new method, which is hard to explain. I sort of angle my foot in and then twist my foot so my ankle moves out away from the crank and then (with my foot still angled) give the button a good kick with the inside of my heel/foot. This method seems to engage the gear a lot better than the rub method and it works great with both 125s and 150s. I guess it helps to have big feet when using a schlumpf with long cranks though, my riding shoes are 11.5 US.

I also do this.

Regarding downshifting, I’ve found that I’ve learned to shift my hips back ever so slightly as I downshift, kind of like I would if I were gliding or wheel walking. That way I don’t fall off the front waiting for the low gear to engage. Also, I shift with a heel kick going down, whereas I use a heel roll going up.

The other thing that I’ve found myself doing sometimes is shifting with the foot off of the pedal while the non-shifting foot rides one-footed for a fraction of the pedal stroke. I suspect this technique might be more useful when I switch to longer cranks. (I haven’t had a chance to try since RTL because my hub is being worked on.)

I’m still learning to ride a KH guni, not ready to try shifting. (The weather, a bad cold, and work have kept me off the beauty.) Unfortunately I have bad habit of dragging my heel on the crank arm, so I’m paranoid that I’m gonna accidentally shift the guni. On top of that I had managed to mess up the allen hole of the guni crank bolt in my new KH geared hub.

Since I didn’t know how long the wait would be to get a replacement guni crank bolt from schlumpf, I looked for a local solution. Turns out that by drilling a 1/4 inch hole lengthwise through a standard KH crank bolt, it could be used in place of the guni crank bolt. The 1/4 inch hole prevents the shift rod from being damaged. With the drilled bolt you can not mount the shift buttons, but that worked out well for me because; I didn’t want to shift on the fly yet, and it left no possibility of an accidental shift. Manual shifting can be done by pushing the shifter with a thin rod through the 1/4 inch crank hole.

Turns out I received the new guni crank bolt from schlumpf in 8 calendar days :slight_smile: Wow, So Fast!!! So the drilled standard KH bolt wasn’t all that necessary.

I only mention the drilling of the KH crank bolt in case it’s a handy solution for someone else. I am no expert on the working of a guni, so while it seems to me a working modification, I don’t know that it isn’t harmful to that ‘worth it’s weight in gold’ hub. I have used it for a very short distance of riding without any apparent damage. Also drilling the stainless steel KH crank bolt will likely ruin a couple drill bits. As for disabling the shifting, I expect that not installing the shift buttons with the special guni crank bolts (I have not tried that) would provide the same result.

Given that I messed up the allen hole in the guni bolt while tightening the cranks, I’m thinking it may good to use the drilled KH crank bolt to initially seat and tighten the cranks on. The drilled KH bolt uses a larger allen wrench size and I haven’t messed one of those up. Then when the cranks are on tight, replace the drilled bolt with the guni bolt.

I shift like Corbin. But I need 2-5 revolutions if I want to shift down. I think my left feet needs more training.
The speed ist between 10 and 13 mph.
I use the 125 or 145 Quax cranks at my 36". That are straight cranks. If I remember right, I have only one accidental shift during a short downhill.
During normal rides on streets or soft graval I have no problems.

I’m now always shifting with my heel, no more ankle-bone action.

The pegs on the pedals make it tricky to rotate your foot and nab the button. If you’re having trouble you might try some less-aggressive pedals, at least till you get the hang of it. Lightening up the amount of pressure you apply to the pedals also makes it easier.


Good thinking. I used to do the ankle method, but the heel gives you a safer and more predictable shift.

As far as aggressive pedals are concerned, I am using MG-1s which are quite sticky, but I use a trail running shoe that doesn’t have a sole made for sticking to platform pedals. MG-1s plus trail running shoes (with a pull lace system) work quite well for me.

Playing with how far the buttons stick out also will help shifting. I found that moving the button as little as one rotation out sometimes makes a world of a difference.

I’ve recently moved my geared hub over to a 36" uni and also traded up for some 165" cranks. These big cranks give me great control and acceleration on the wheel, but make shifting (with my small size 8 feet) a pain.

I’m finally starting to get the hang of it, but have to really move my feet to hit the button. I shift my foot out to the far edge of the pedal so I have almost nothing but my big-toe on the pedal, then swing my heel into the button. Not the easiest riding position, with one toe on the pedal, but the extra control/power of the big cranks makes it worth it. Hopefully my legs will get stronger so I can move back to some smaller, easier to shift, cranks.


I started with 165 and quickly moved to 150s. They make shifting much easier, almost second nature now. I went for a long smooth single track ride this weekend on my new (un-geared) 29er and I kept finding myself trying to shift a gear that wasn’t there at the crest of every hill.
Anyway, those long cranks made if way too hard and learning to find control on 150s came quickly.