Schlumpf hubs: general discussion

Unicycles and Equipment
1618

Thank you all for the reply.

Wow, Kris Holm himself answering one of my questions :sunglasses: :roll_eyes:

Tried to see how it looks if I put a kh bearing cap on my nimbus 29 road frame, and it seams that what I was thinking about is not possible cause the two pairs of holes don’t fit.
The space between kh frame holes and nimbus frame holes are not the same.

For now my schlumpf hub is on a kh 26er frame and since I just bought it, I only gave it a 20 min try on my parking.
First time ever I ride a geared unicycle, so I was unable to shift with the 137 spirit cranks, and the very first attempts of riding on second gear were epic :D, just like I learned unicycle once again, you know.
After 5 or 6 attempts and few upd, I was able to ride several times the length of my parking and discovered the potential of this very different unicycling dimension.

Anyway, in the first place my project was to have a geared 29er and I guess this is what I will finish to have, but I realize that I’ll have to change the nimbus frame for a kh29er frame.

1619

It’s funny, if you search nimbus and schlumpf you get a few threads with the same people saying the same thing over and over.

Not many people have put a Schlumpf in a Nimbus frame but if the inner lip can be reduced to 3mm wide and less than 2mm deep you should be able to use the hub in your frame.

It looks like Roger Davies has had a Schlumpf in an Oracle frame, but it may have been a prototype so that’s not much to go by. Jacob Flansberry has also used modified aluminum Nimbus bearing holders to make Schlumpf compatible frames.

1620

I don’t know which generation you KH frame is on the Schlumpf but I noticed that the newest versions (with disc tab ) have an asymmetric / triangular shape where other frame (including my old KH 2005 frame ) has the usual rounded and centered bolts.

If this is the case, I may have some symmetrical KH bearing caps in my parts box.

1621

I think I will read the whole thread to increase my general knowledge about geared hubs, but according to what you wrote it seams that the only thing I need to put a schlumpf hub on my nimbus 29 road is a simple file.

I just wonder if the fact that the bearing holder of non-kh frames don’t entirely surround the bearing may result in slippage issue.

1622

So here’s a question.

Why did they go away from the bolt on torque arm in the first place?

1623

The idea was to allow people to use any frame, whether it had a hole for a torque arm or not. It seems like a tab between the bearing clamps would have been a better design, though.

1624

If that’s the case then they didn’t succeed.

1625

The ISIS Schlumpf hub was actually designed to work with 2008 and later KH frames (and vice versa).

That isn’t to say that other frames can’t be made to work. I would much rather remove a bit of excess material and clean up some welds with a file than start drilling into frame legs to get a geared hub to work.

The knurled bearing isn’t perfect but it was a big step forward from the torque arm. The next logical step would be a solid mechanical stop which only requires modification to the lower bearing cap on older frames.

1626

This would not only be the next logical step, this is the modification for the 2015/16er model.

1627

KH bearing housings have been updated for this modification long time ago …

1628

Yes, with the 2012er models

1629

I can confirm the Nimbus Crmo clamps need modification. My friend used to ride his Schlumpf in his nimbus Muni frame. We just had to reduce the size of the inner lip. But it worked!

The Nimbus Aluminum all need modification. But they fit. There’s always a way to make it fit!

I also ran my Schlumpf for a while in a frame with pressed bearing holders (I do not recommend!!!). It wears out the bearings way faster. Obviously I ended up making a frame to fit my wheelsize. That was when I first got my 650b, I was still not Tig welding at school!

1630

Is this because you had to tighten it down too much, so it squished them in? I wonder if that will still be a problem on the 2015/6 one we are all waiting for. I hope not, my qu-ax needs an upgrade :smiley:

1631

I’m pretty sure it will still be a problem. Schlumpf hubs are not designed to be run in staped sheet metal bearing housings, neither the old one, nor the new one.

But if your investing a four-digit amount in an new Schlumpf hub, take the 100 extra bucks and give it a new frame …

1632

Yeah I agree with this - I’m just not sure my parents will see it that way :smiley: At least buying a hub + rim I can pretend like i’m just upgrading my current uni instead of buying yet another one!

1633

First ride yesterday.
Things didn’t happen very well, firstly because my left knee has been hurting for about maybe two months now, and not only the tyre was too loud (1.2kg) but also I chose the 110mm holes on the spirit cranks, so the pain kicked in after the very first km.
Secondly, if I managed twice to trigger the second gear while riding with those 110 cranks, I didn’t manage to stay on the guni when it engaged.

Then I decided to switch to the 137mm holes but this time I was just unable to reach the button while riding.
The loop was 6km long, I finished by few attempts of starting on 2nd gear with the help of some trees or something to mount on the uni, cause for a reason I don’t totally understand I’m unable to free mount this 26er when it is engaged.
After few tries I was able to ride at 2nd gear, imagining I’m on my 36er, and this is exactly what it feels like, excepted that the seat is much lower.

Also I didn’t like at all the zero saddle, not only it is hard for the butt, but also I find that I have near zero lateral control when I try to ride without holding the handlebar.
I sold it this morning, I will use the kh freeride of my 36er which is more comfortable than the more recent free ride that is on my 29er.

I just received a 620gm schwalbe super moto 26x2.35 tyre, a FOSS tube and a pair of 127 spirit cranks (single hole) that will probably be easier for switching and a little faster in low gear, but with this knee issue I should stay on the 137 and shouldn’t use the 2nd gear for a while (excepted for training to switch gear).
Thing is a 26er with 137 cranks is so slow (low gear) after being used to a 29er with 125 cranks or shorter, but I must avoid any pain or stop to ride as soon as I feel it, which exclude any ride with other unicyclists until I recover from this injury.

knee issues can last very long…
I had just found a way to avoid ITB syndrome (by lowering the seat on all my unicycles) and this other kind of (internal) knee pain kicked in 2 months ago after having changed a 650gm 29" tyre (super moto) for a 1200gm tyre (hookworm) and since it is even worst than the ITB pain, cause it triggers very much sooner…
I immediately put back the super moto but this was too late.
Later I rode my new kh 26" muni (fixed hub, knard 26x3 tyre) with pierrox but the pained invited itself after 4km and made the rest of the ride very unpleasant and much painful at the end…
Very much tight knee brace could be a help, have to figure out which one to buy.

The more I have unicycles the less I can ride, this doesn’t sound very fair! :frowning:

so far I have read 30 pages of this thread and the testimony of one of you guys (uniShark) 5 years ago makes me understand that riding engaged may be not for now, and that 26er guni is probably more accurate in my case than a 29er or a 32er guni.

I also think that putting my pedal extenders on the 137 holes could help for learning to switch (thanks to my duck feet)
I’ll give it a try latter.

1634

Great write-up!
Here’s a suggestion on shifting – your heel is not the only way to shift. You can also shift with your ankle. (But it helps to have high-top shoes.) This is how I do it. I find it more “natural” for my riding than heel shifting. Changing crank lengths doesn’t affect it very much, either.
Good luck!

1635

That’s how I shift - or at least it was when I last rode my guni. I was working on trying to heel shift as it seems like it ought to be better, but find it a lot harder. I have small (UK7, US8) feet, so find it tricky reaching the button - I have 140 cranks on which I can just about manage with, though I have to shift my feet back a bit on the pedals compared to how I’d normally ride. I’ve tried 125 cranks which make shifting a lot easier, but I find it too hard riding and controlling the guni with that length - that’s on a 29er (and I’m still a relative novice on the Schlumpf).

Which brings me onto what I alluded to at the start - I’ve not ridden the guni for 8 or 9 months, because last time I rode I got problems with my back (the first time I did that on the guni it stopped me doing any uni riding at all for almost a month). I need to work on my core strength to cope with the extra demands - I was fine when I first rode it, but have lost a lot of fitness since then. Unfortunately various health problems have meant I’m even less strong now. The point I’m making? It seems a bad idea to learn to ride a guni when you’re carrying an injury as it’s pretty tough on the body - at least when you’re learning, I’m sure the experts only have to use the same small corrections I do when riding ungeared.

1636

I would get another frame. Mine was temporary, until I could make one. It destroyed the bearings, not even joking! I can’t find the picture though.

I’d invest in a new frame too!

1637

To be honest the only reason I was holding out on gearing up my 36er was because I thought the 2016 hub would be usable in my current frame. If that’s not the case I might start keeping my eye out for available older ones (though I understand they’re like gold dust round here…)