This worked really well moving the crank on the (apparently tapered schlumpf spline)
I did not need to use a mallet or any hitting of the crank onto the spline.
I was able to install the pretighting bolt with washer onto the schlumpf axle with 4 hand turns to have the washer against the crank before starting the installing with 8mm Allen key
I used a UDC 8mm (with 200mm long handle) and move the crank onto the spindle.
With all the advice of ensuring the crank should not be given a chance to move (use of Loctite on interface of spline and crank), I added a 2mm spacer and moved the crank onto the spindle until the spacer was not able to spin. (as per Mindbalance’s video.) I did not use any grease to ensure no movement of installed crank.
See below the pretightening bolt and washer before I began to wind up the bolt to steadily move the crank on. I felt consistent pressure on the Allen key up to the crank being up against the 2mm spacer. And then I stopped.
The pretightening bolt was applying force to the outside of crank and the Allen key was located away from the shifting rod. Also being hollow, the bolt did not interfere with the schlumpf shifting rod.
I installed the schlumpf axle bolt with just enough force to be snug tight, nothing more. Maybe just 1/8th of a turn more after feeling resistance.
Missed this until now, in the thread.
The bearing housing hole in the latest KH frame production (the frames with dual disc tabs) is intended for the KH/Schlumpf bearing lock. Backstory for the choice to place it in the lower half: earlier in the design process for the new geared hub, the lock was 8 mm wide, which was too big to put inside the frame (and too big generally). Given the long lead times involved with frame production, we made a safer choice to place the hole in the lower bearing housing where there would be no chance it might interfere with frame welds. As it turns out, drilling into the fork section is fine. But the key message is - the latest KH frames don’t need to be modified to fit the geared hub.
-Kris
I would love to know if anyone has issues with using the lower bearing housing to engage the Schlumpf hub lug. It seems like it would be easier to engage the wheel with the frame, as you just have to place the hub on the frame bearing retainers and then you can easily see whether everything is nicely aligned and simply place the bottom retainer where it is obvious that it is covering the lug properly. OK, not a real big deal, but a nice convenience, and if the hole wasn’t drilled properly, you can easily get a new retainer.
So, I guess the only issue would be whether the braking forces slightly influenced the bolts holding the bottom bearing retainer to loosen. Otherwise, it seems like that is the best place for the hole. (And if KH had decided it would be OK, that is a good sign).
I think this works well with a KH frame - but I would be less inclined to use this approach on a different frame type.
The KH bearing caps have always to my mind been the neatest closing to the frame and this gives me reassurance that I can be certain it is clamping down on the entire bearing.
The photo here makes it look like the lug isn’t central - but this is more an optical illusion - it is central to the bearing cap hole.
With other frames I see a small gap either side of the cap and while this isn’t a problem in so far as securing the wheel into the frame I’d be concerned about placing the bearings in with the lug central to them.
I agree with you that isn’t isn’t entirely confidence inspiring installing he lug into the forks drilled hole as one can never feel totally certain they’ve “got it” located, but I’ve come to believe if the bearing is seated evenly then the lug must have found its home in the hole that’s been drilled.
As for which is stronger - I think for the KH style caps there’s little in in, but for other frames I’d prefer the hole in the forks and not the caps - as I’d picture the caps one day getting loose one side and causing it to slip or be misaligned. If this happened it would be easier to check and replace any damaged area of the frame, but I think it could more easily happen in a non-KH frame.
These are just my musings, but I like the way the KH frame system works and it is nice to know this is deemed safe by Kris himself
I did the same with my 36" Flansberrium frame. For me, it’s a much better solution than the notched bearing.
With 5-6 Nm of tightening on the 2 bearing cap screws, I can’t imagine how the hub could slip.
From this thread comment re spacers. I just wanted to chime in that I’m using them so far with no issues and cranks don’t seem to get loose. From time to time I get perhaps a few degrees of a turn in terms of tightening.
I do also have it on good authority (KH himself) that the use of them is a good thing on these new hubs.
The protector rings should butt up against the inside wire rings - so long as they’re snugged up but not massively tightened I think it is better than no spacer where the crank is free to work its way in ways.
Opting to not use spacers is in line with what Florian advises so you take whose view to trust here. Hub making, or crank designer (I’m using KH Spirits)
Thanks for the details! We had a private chat with @r4nd1nt after my comment on spacers. During this chat, I had looked for info on “why is it discouraged?”. I found your first message telling that you use spacers. It was strange, as it was against others recommendations.
However, if spacers were wrong for a long time, this may explain why I was thinking that they were still wrong.
Florian doesn’t see a need for them even if there’s a gap between inside crank face and protector rings.
ISIS crank specs expect a hard stop for crank install to be solid.
Kris seems to agree here re use of spacers and confirmed my decision (among a few others on these new hubs) was the right thing.
Why has this changed from previous hubs?
I think the axle may be a touch longer and / or a touch tighter to fit cranks on - meaning that try as one might you’d not get cranks on and close the gap to the official bearing protector rings.
Hence 2mm spacers.
Given the grey area around this I did sense check my call to use them with Kris directly as I felt I needed to know it wasn’t bad for such expensive hubs. I feel reassured now that it’s good to use in the 2022/23 hubs - but older ones should follow the received wisdom that collectively the unicycle community has come to know/glean from their usage.
One day a user-sourced manual with tips and tricks and facts should be collated.
Hey everyone - here’s an update on a prototype I’ve been testing for about half a year: an adaptor to fit microspline (Q-Axle compatible) cranks such as the KH Boundary crank to the most recent model ISIS KH/Schlumpf hub. Florian Schlumpf produced the prototype. It is deceptively simple and ingenious: a shim that is ISIS on the inside and microspline on the outside, with a different axle end bolt and shifter button.
The rod-shaped shifter button looks like it would be harder to shift, but I’ve found it shifts well. Unlike the mushroom-shaped shifter button, the rod is supported inside the axle bolt all the way to the bolt face, which eliminates flex and seems to make the button feel more solid.
This is a prototype and needs a minimum volume to produce. Two questions:
Would you be interested?
Besides the KH/Schlumpf hub, do you think there might be interest in this for any ISIS hub (geared or not)?
Depending on the price, I may be interested. I’m pretty sure others would be, too. Lots of people still have ISIS hubs, while slightly moving to Qaxle. This could be a great middle step to avoid having to replace the hub when buying new Qaxle cranks.
Does this completely eliminate the freewheel issue with loosening cranks? I’ve had a bunch of them lately with Spirit cranks
I ride with on a M0648 hub since december, and I have had to change my cranks once because of the ISIS interface wore down, and my current cranks have a tendency to get loose over time if not tighten enough (my left crank has been tighten to the point of barely touching the bearing cage and I have got no problem, but the right one hasn’t, so it has moved, which lead me to tighten it to the same level has the left one, but it wasn’t enough, so I have needed to sand the crank to tighten it a lot more).
All that to say that I should have used a spacer, but on <800 hubs it isn’t possible. Does your system solve this problem ? If so, I am definitely interseted since I fear a lot a loose crank, which would be a real problem on longer rides (100 km and above).
On the first picture, I don’t see any way of blocking the adaptater in translation beside the friction between it and the hub. How is it managed ?
Love this Kris - seems like quite the upgrade to my eyes.
yes and I don’t personally mind if it ends up being a bit expensive given that I get it is a niche item but would sit there as an option. Better to have it available than not it my view.
Granted people buying this will be low volumes I’d say - it doesn’t mean that demand wouldn’t continue especially as Spirits flow off the market. And to my eyes this is a better shifting set up too, so it seems just better.
I suspect the answer is yes should splined cranks become the dominant option and people prefer to invest in those and have backwards compatibility with ISIS hub unicycles.
Without such an adaptor it means all ISIS unicycles will have to go to non-KH branded cranks - and for someone who likes the Q-factor, design and general build, that’s a shame.
Thanks so much for sharing this on the forum and for pushing forward this area and how Schlumpf hubs can be improved
Kind of presuming these parts are no longer needed as the concern with ISIS cranks creeping inwards is over when using these adapters and splined cranks.
Yes, I’d be interested for use on a non-Schlumpf hub – initially just to have lying around, mostly just for ‘insurance’, that I could put on your/QuAx cranks on existing wheels if I wanted (say onto a 125mm Nimbus hub for example). .
If you were doing these for regular ISIS hubs would you have a ‘more-standard’ end cap you could fit with an Allen key rather than the Schlumpf specific version?
Also, I’m assuming this would have to come off to change bearings on an ordinary ISIS hub, do you think there would be any issue pulling it off the taper? Maybe there is a slot in it to align with the crank slot though.
Sorry to be a forum pest on this one, Kris - @danger_uni - just curious if any decision has been made - and if not yet if there’s a rough timeline?
I ask as I am very shortly going to be buying a set of your cranks - and will have to go Spirits which while perfectly good, if I know an adapter is going to be available I’d hold fire on the purchase or buy the Boundary cranks in anticipation of it
Re spacers: because securing the crank doesn’t require high axle bolt torque, and given the spacing, I haven’t been using a spacer between the crank and bearing face.
Re fitting an Allen key on the axle bolt: strictly speaking, I think there needs to be a reason to use the spacer - e.g. because the Q-axle crank design offers something that you wouldn’t otherwise get. Otherwise it will be better to use the original spline and not introduce a spacer. There is a clear need on the geared hub, less sure about standard. If produced then yes the axle bolt would secure with an Allen key given there would be no need for the shifter button.
Re a production schedule. No decision has been made yet, and as with most things to do with this hub, best not to hold your breath. I would go with Spirits if you want to get going sooner rather than later.
