Schlumpf hubs: general discussion

Unicycles and Equipment
622

No disrespect, but I meant “reduced to” though “limited to” would also work. My first love is running, especially long distance (ultra distance) trail running so not being able to run is a huge blow! This is the first time in the 20+ years I’ve been running that I’ve had an injury that would prevent me from running/walking! But as my wife keeps telling me, “You’re long overdue! ;)” (she has had several running related injuries over her career). I don’t like it, but I guess it’s true.

Fortunately I think I’ll be able to ride as long as I’m extremely careful not to impact my heel, so that means fairly easy routes and pavement for a few months. Still, better than nothing!

623

I now have 100 miles on my 36 guni. I am getting more comfortable on it. My speed is gradually coming up, and I am riding in high gear on more challenging terrain. This morning I did a fifteen mile ride with an average speed of 11 mph, which is similar (but still 1 mph slower) to my speed riding it with a KH 36 an 125 mm cranks. On a smooth, modest downhill my top sustained speed was just over 16 mph and it felt reasonably stable. The lower cadence does bring a bit more control. I can ride a very modest uphill gradient in high gear, but I do not think it increases my speed yet. (I can ride up slight hills in low gear at 12 mph.)

Shifting is coming along. I still sometimes come off the back on an upshift, but it is not scary. Downshifting is more variable, as others have noted. Sometimes it is easy, and other times I am starting an uphill and wait too long for an easy shift. Today I tried to stop at an intersection and then get started again in high gear (because I was too lazy to shift) and had a low speed UPD which had my nice new guni bouncing towards the traffic lane–yippes! Next time I will down shift or get off at a busy stop sign.

Scott

624

I tried 135’s and yeah, they spin nice, but they are inadequate for downhill control and they are no better for technical riding. I have an XC machine which excels, my 29er, so the 26 guni is supposed to be a muni with a high gear for easy sections of trail and road connected trails.

I think the difference over crank length might be my size 13 feet, long legs, and big thighs, which make reaching buttons quite easy and powering big cranks my preferred MO.

Like Munisano, I am also an trail ultramarathoner, so when I started cutting back on my running and found mountain biking to be a bore, the big draw from muni was getting in a killer workout on the trails without having to bust out huge miles and long hours. Ultrarunning takes a lot of time and is not all that “core building”, whereas riding muni is a , excuse my language, a “ball buster” of a work out.

I rode a local trail last night, used the high gear on some wide double track, man was it fast, but really not a good place to go so fast, unfortunately 39" does not go slow very well on rough terrain. At this point I can’t really use it on any of my local trails, so it’ll be mostly a uni I use when I go to big trail networks like Pisgah, Bent Creek, etc… and the occassional greenway ride. I don’t ride road, gave it up for safety reasons, too many times under/over cars in the past, no longer willing to risk what I have. Cars win, I concede my loss.

Honestly, has anyone approach Schlumpf about producing the hub with a smaller step? I’m not the only one who’d like less than 50%, shoot, even 25% step on a 29er (29/36.25) would be better than a 26/39.

625

Yeah, the thing is though, at least for me, the shorter cranks make my spinning a bit less “choppy”. I run a hydraulic brake so I’ve got plenty of control on the downhills. Also the shorter crank length has proven itself on the technical stuff as well as I’m less apt to pedal strike rocks on my typical routes. On everything else the shorter cranks are nice as well, feel like I have more power climbing, definitely faster overall and the reduced choppiness translates into a more efficient roll in high gear. Again we are all experiments of one and I think for my height/weight/wheel size I’ve found the optimal solution… :slight_smile:

626

I like the 150 hole on my 24 guni. I tried to 125 for awhile. It was easier to shift and nice on some parts of trails, but my technical climbs and descents suffered a little. So I went back to the 150s. I would like to try 135s, but have not been motivated enough to mess with changing cranks.

627

I was very leery as well, but decided to finally give my 137mm cranks a try (had them on my unused trials unicycle). Totally love this crank-tire size ratio for the 24" (thanks to Kris Holm for starting a thread about this a while ago, can’t find it). Won’t go back to 150s, no reason! 137s are way more smooth for high gear, can climb and descend just as well as the 150s and they are very good on the technical stuff. Seriously, try it out!

628

…and much less tiring.

629

I switched to 137 a couple of years ago for my ungeared Muni (thanks to Beau) and overall it is a total win. Occasionally they are not long enough, but 99% of the time they are great. If I had a geared 24, that is what I would use as well. Great length!

—Nathan

630

I have been running 140s on my 24" for years now and also found that crank size to be pretty ideal for the geared 36er in most situations.
On the geared 26er I used to have Nimbus Ventures 150mm which I liked. But a couple of days ago I had to replace them because they were wiggling around even though the bolts were tight. So first I thought I’ll put the dual hole moments 150/125 on now. But I really didn’t want that added weight so I had the idea of putting the Tensile 140mm cranks on that one and putting my then unused 137mm Moments on the 24". It turned out to work very well for me.

631

Personally I prefer 150’s on my geared KH26, for the terrain where I live. But one of the side effects of riding so much on a geared uni is that, like Nathan, I switched to 137’s on my ungeared KH24. Other than being smoother, another positive to the shorter cranks is that it’s easier to absorb shock in non-ideal crank orientations.

Also, it’s an expensive way to learn, but becoming used to 2nd gear on a geared 36 sure helps riding uphill in 2nd gear on a geared 26! Try that for rationalization next time you want to convince your partner that you should get another one. =)

Kris

632

Kris, do you ride 150s on your 36 guni? After riding with 110s for so long, I notice the wobble with the 150s. Not horrible, but noticeable. It is amazing to pop into low on the 36 and have it feel like a small wheel!

633

Yes, I do currently have 150’s on my 36 guni. Maybe I should experiment more with shorter, but so far it lets me spend a higher percentage of time in 2nd gear.

Kris

634

I’m not sure about going down from 150s on my 24 guni. For a good portion of my rides it would work, but there are a lot of spots that barely get through with 150s.

635

Good point, it is only under ideal conditions that I have really felt like I might want shorter cranks. I have noticed that upward inclines are harder in 2nd with 150s than unguni with 110s. I guess shorter cranks would exacerbate that effect.

636

I chose to have Bronson Silva build my Schlumpf hub into a KH36 with 150mm cranks. It all comes down to where you do the majority of your riding. The 100 mile Louisville Loop (95% funded, 30% complete) will network our parks with paved multi-use paths (GreenBelt, GreenWay, RailsToTrails). This has been my un-geared 36” Nimbus (disc brake) Impulse’s “destination of choice” and played a part in my decision to “go big” with the Schlumpf.

My kids (Girl 7, Boy 6) play a lot sports so my time is very limited. Most of my riding is out-the-door and down-the-street staying close to home. The Loop is flat (move pedals to 125mm hole) but my neighborhood has killer hills that require the leverage of 150mm cranks. The geared 36er seems like (If I can even ride the thing having never tried a geared unicycle of any size.) it should be a good fit and the next logical step for me.

Thank you Kris, for your reassurance that my plan to learn-how-to-GUni on the big 36” wheel is not the total ass-backwards way to go about it. Perhaps, when my kids are old enough to ride mountainb*kes, I will move my Schlumpf hub into a smaller wheel and get back to the well-manicured trails of Cherokee Park. I sold my 24” MUni (much preferred the 125mm hole on it) to fund my distance riding.

637

Loose crank on this morning’s 24 guni ride. Ugh. Oh well, can’t complain too much, this is the first time in a years worth of riding. Did get it tight enough out there to get back to the car. Came home, got out the torque wrench and the loctite and cinched up both sides real good. This time I knew to use a regular 8mm bolt to set the crank, and then put on the wimpy 6mm Schlumpf bolt. No stripping - phew!

638

How often do you check cranks? I changed my cranks two or three months ago (Bronson changed them for me). I never check them for tightness. Should I, every so often? If so, how often? All I’ve done is add grease.

639

I have just been out for a second session on my 36 guni. I mistakenly thought that I was coping well and clicked down to low gear. The change was smooth, but my brain was still in high gear. I can see one of the keys to learning is being able to switch your brain into the other gear. Next time I go out, I will have short sets of high and low so I can get used to the ratio changes.

However, I must say, it is so much fun cruising along in top gear on the 36.

640

I have never checked them. I think the grease from the hub broke down the loctite over time. They did stay good for about a year though.

641

I’ve had my new 26er GUni for a couple months now, and must say that I really like it a lot. I got shifting down faster than expected, and it has pretty much replaced my 24 and 29er for all-purpose MUni riding. I still use the 24 for the really technical trails, and even though the GUni can handle it, I don’t want to over stress the hub beyond its limits.

One thing I noticed immediately was the extra weight from the hub! In fact, at 19.3 pounds, my G26er weighs more than my 36er, with the handle and aerobars! This weight does include a short T-handle (same as Kris’s setup) but the hub is where all the extra rotational weight is coming from. Having said that, I have mostly gotten used to it, but when I pick up my KH 29er, it feels light a s a feather by comparison!

I’ve ridden my GUni at several trails and lately I seem to be doing most of my riding in high gear! I really like the feel of it now, whereas in the beginning it felt really strange and I would feel a kind of “rocking/bobbing” motion with each revolution. Now it’s fun riding over a variety of terrain, and to try staying in high gear as much as possible.

Last weekend while riding one of my favorite trails, I was about a half mile from the top, climbing is 1:1, when a bunch of fast trail runners past me like I was standing still. After I reached the top, I kicked it into high gear and started the long, mostly flat stretch of the trail. One by one I started passing the runners–like they were standing still! :smiley:

On a technical note about the hub, when I first got it I noticed some grease/lube around the seal area on both sides. I was concerned about it so I contacted Bronson and he basically said “it’s normal” and to “expect it to leak a little”. That seemed strange to me since I thought that the “seals” are supposed to to just that. Seal. I thought that if the internal lubrication could leak that easily from the seals, then dirt, moisture, etc., could find its way in.

But when I asked Kris about it, he also said it was normal to have a little leakage. Since riding it now for a while, the leaking seems to have all but stopped. I also check the cranks and shift button set screws for proper tightness before each ride.

Kris and I also touched on the possibility of dirt, mud and debris clogging the set screw holes when riding in wet weather conditions. This got me thinking about what I could do to prevent this from ever happening. I came up with a solution that is both simple, cheap, and totally effective. You can see the idea here.

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