Schlumpf hubs: general discussion.

[dmacuni]

Originally Posted by scotthue

. I'm pretty positive that the new cranks and frame work great together.

My New kh36 disc frame and spirit cranks work perfectly, assembled in about 30mins when I got into it, and after a week of riding my 30km return commute every day, they're still working perfectly.

Top work kris; you can't please all of the people all of the time, but you can please some of the people all of the time.

And Scott, you're an animal.

[nathan]

That's good to hear Daniel (and just what I expected). Congratulations on the new uni!

[Tucson Uni]

Hey Kris, I am looking at moving from a 24 guni to a 26 guni. I am wondering what set-up you are riding these days. I want to use the new Spirit Cranks (150/127). I am trying to decide whether I want to invest in a disc brake. What are your experiences with the disc brake for geared muni? Also, what is your preferred tire choice. I am looking for a lighter setup than my current Duro24x3, but the trails here in AZ are pretty rough, so not too light. I was thinking of the Ardent 26x2.4.

[danger_uni]

I'm using a 26 guni, but just built a 24guni as well just to try it out again. It's been over a year since I had a 24 guni setup so it's hard for me to compare (haven't been out on the new setup yet). The disk brake works well on the 26 version; have ridden that for about one year now.

My reasoning on the 26 versus 24 setup is I prefer the KH24 on the really technical DH trails, and around here they mostly involve a continuous climb then a continuously technical descent. So I'd never get into 2nd gear anyway.

I like the 26 size for up-and-down technical XC in 1st gear, and the 2nd gear is still controllable for me on singletrack (unlike the 29).

I like the High Roller 26x2.5 for All Mountain but you might try sourcing a 2.7 (single ply) of the same model, if you can find one. It's a great tire - major volume at only about 1000 grams in the 2.7 size, and well supported on a 47 mm wide rim.

New weights on these unis:
KH24: 6.1 kg
KH26: 5.5 kg.
The difference is entirely the tire.

The one thing you have to get used to on the disk brake is that you can no longer simultaneously shift and brake. That's something that may bother some people. I thought it would bother me but it didn't seem to take too long to get used to it and adapt.

[Tucson Uni]

Thanks Kris. I have been running my 24 without a brake, so the no braking while shifting should not be an issue. I am getting a whole new uni, so I will keep the 24 for now (insurance against long repair time if required). My thoughts on the 26 are that the lighter wheelset will be more responsive and quicker. I have been working on riding in high gear through rough single track. With practice, I am finding it to be quite doable. It will be interesting to compare the 24 and 26 for this kind of riding. Cushioning with the 24 versus lightness and better rollover capability(?) with the 26.

[scotthue]

Originally Posted by scotthue

Where? I believe what Kris was saying is that if you want to use the Spirit cranks with the older (non-disc mount) frames, you would have to grind them down. I'm pretty positive that the new cranks and frame work great together. But I can let you know this afternoon when my 36 frame comes in the mail. (I managed to bend the D'brake when I stopped really quickly in high gear.)

So I got the frame this afternoon. I did have to file down the welds on the inside of the bearing caps so that the frame would not rub on the Schlumpf seals. I thought this was something Kris had dealt with in the factory on newer frames... Also, on the knurled bearing side, I had to file down the top of the bearing cap since it was hitting the frame before getting it to the requisite 5-6Nm. I think I had to do this since they are machined and don't have any paint on them. (I didn't want to have the same problem Terry had with his stripped frame.) Other than that, it was a pretty easy setup. Also, the clearance between the the rotor bolts and the bearing cap is probably less than 1mm; a little nerve-racking. I had to cut down the frame too because I'm short, but that was simple with a hacksaw and a guide.

Pictures:
1. Ground down inside of frame.

2 & 3. Rotor bolt clearance.

4. Whole uni.

[danger_uni]

Good to hear it worked. Murphy's law I suppose, but on the 4 KH/Schlumpf hubs I have in my possession, they don't rub although it is close.

Ideally, the KH/Schlumpf hub should have a solid crank stop between the bearing and crank. Because it doesn't, there's the potential for variability in the crank position. Because the ISIS spline has a 1 degree taper, simple trigonometry means that the slightest variation in spline diameter has a discernable effect on lateral crank position. At the same time, a 20 mm wide bearing housing is the narrowest that I dare go and still maintain strength.

On the inside of the frame, the current minimal clearance was based on a KH frame that Florian had, that didn't rub. I think that had something to do with having a "Swiss perspective" on adequate tolerances. I thought I'd dealt with it in Taiwan last November, but it's extremely tight and it looks like some frames still will rub slightly.
Really, the best solution will be to increase the clearance on a future model of the KH/Schlumpf hub. Will see. That is nowhere near being produced though, as there are currently plenty in stock.

Kris

[Tucson Uni]

Hey Scott, looks great! I might need to make that upgrade for my 36 guni. What crank length are you running now? Are those platform pedals? Did you move away from using the clipless?

[nathan]

I like it. Looks cleaner than the D'Brake adapter.

[GizmoDuck]

Originally Posted by danger_uni

Really, the best solution will be to increase the clearance on a future model of the KH/Schlumpf hub. Will see. That is nowhere near being produced though, as there are currently plenty in stock.

Kris

Thanks Kris,

I'm waiting on a 180mm rotor to arrive so I can fit your spirit cranks to my Triton. I'm fingers and toes crossed at this stage, because it looks like it will be a very tight fit- those disc bolts don't clear the bearing caps by much do they?

Is it possible to grind down the crank to move the disc further outwards? That might be an option for me because I'm not too keen to trying to file titanium. Or perhaps in future models- can't you move the disc further outwards? Or get Florian to make a longer axle.

[danger_uni]

You can't grind the cranks - the rotor fits on the cranks such that there is 20 mm clearance between the rotor and the inside face of the crank. The max standard for disk calipers is 19 mm, so at least 1 mm clearance from the caliper to the crank arm. This is sized closely because there is a standard here to follow on the caliper, and to minimize the outwards flare of the cranks.
I believe that Turtle had to grind his Triton frame slightly.
Yes the KH/Schlumpf hub ideally needs to be about 4 mm longer (2 mm longer each side), IMO. Again that will be reviewed in future. Next time around I want the crank position to be identical to the Moment hub.

Kris

[GizmoDuck]

Originally Posted by danger_uni

I believe that Turtle had to grind his Triton frame slightly.
Yes the KH/Schlumpf hub ideally needs to be about 4 mm longer (2 mm longer each side), IMO. Again that will be reviewed in future. Next time around I want the crank position to be identical to the Moment hub.

Kris

I'm not sure if Turtle will read this...but do you know if he had the Triton disc frame or if he used the bearing cap mounts?

Maybe I could grind the bolts. Anyway, I'll find out on Monday if it fits.

The SINZ MTUni cranks rubbed against the brake adaptor....probably can be ground away but I hadn't got around to doing that yet because I'm intending on using the Spirits (no spacer required).

[danger_uni]

Could be wrong but I believe that Turtle has a Triton disc frame.

[MuniAddict]

My shifting is pretty consistent and I usually get it first time.

But sometimes I inadvertently do what I call a "slow shift", which causes the wheel to "lag" for a moment before it engages. Several months ago, when this first happened, I wasn't ready for it and because of the sudden lag, which is actually a very short coast, it threw me off. Since then I've been ready for that eventuality, and when it happens I can catch it and continue on.

At 1:04 you can see this "lag" in the wheel as I shift into high, and the wheel juts forward momentarily before I catch it. Sometimes this happens when the shift button is not engaged with enough direct pressure. It still shifts, but just not as fast, hence, the lag. Also, just to be sure the button is fully engaged, I usually "swipe" over it again on the next rev! I think it mostly likely happened this time because I was riding and filming at the same time, so I wasn't fully focused on my riding.

Btw, this footage was actually made to test my new canon powershot Elph p&s camera. It's super tiny but packs a wallop of great quality hd video and stills.

Canon Powershot Elph 300 HD & still test mtb ...

[Tucson Uni]

Just put 137 cranks on my 36 guni (instead of 150s). Took a short test ride. It is MUCH easier to shift. I'll see how it goes on a real ride. Trying to decide what length I want to get with the new Spirit cranks and disc brake.