On my ungeared unis I use spacers and don’t get these problems but with the Schlumpf hub one is not supposed to use spacers so the cranks creep inwards slowly. I had the first gen ventures on my G26 for some time but at some point they couldn’t be tightened anymore. The tensiles seem to last longer.
So for Schlumpf hubs it would probably be a good idea to have some other kind of stopper. Maybe one could make the splined part as a steel insert to minimize the creeping?
Thanks Roger, that’s some good information.
There is quite a bit of difference in how the cranks fit on the same hub(s). I have various lengths of KH (Al), Koxx (al), and QuAx (steel and Al) cranks.
The Ventures and Moments fit furthest onto the new Nimbus hub splines, the Koxx and QuAx have the most crank spline remaining and seem to fit the spindle splines best..
So maybe a hard stop would only be helpful on the Schlumpf at present, but my thought was to combine a hard stop with a pinch bolt cranks, that way we could adjust for increased tolerances.
The aluminum spacers are not quite a hard stop, the aluminum can crush and wear, also the bearings can shift the hub on the spindle if you’re not careful to snug up one side before torqueing the other side.
Simply torquing the cranks against the spacers is not enough to prevent wear at the splines, so it’s not a matter of the bolt loosening so much as it is the crank shifting on the splines. I have no problems with loose bolts, only loose cranks (creaking) or cranks that will simply no longer snug up on the splines and go so far onto the splines that the crank splines are maxed out.
Note that when the I say the splines are maxed out, this is where the ISIS bolt “washer” bottoms out on the transition zone (lip)where it changes from splines to threads inside the cranks. I think this was an issue on early Schlumps, which is why the spindle was lengthened on the muni version, yes?
Has anybody tried building up the contact surface of the ISIS interface with aluminium foil or something else yet? Experiences?
That would not work.
I built up the axle surface where the bearing sits once because my bearings kept slipping and it was a pain in the ass. I needed minimum 5 tries per side to bring it to a nice fit without wrinkling the foil before. It was hard to wrap the foil without any small wrinkles arount he axle, kept in place by some grease, and even harder, to push the bearing over it without destroing the foil. And this was a perfect round surface.
For the complex geometry of the ISIS interface, that would be literally impossible!
OP title: ‘Is there another crank standard that would be better than ISIS?’
Square taper, if you (me, idiotically) forget to pack your (my) cranks when travelling.
Otherwise, no. Keep the industry standard, so all our parts still fit together. It’s environmentally and user friendly.
The great thing about standards is how many there are to choose from.
ISIS hasn’t been “the industry standard.” for 15 years or more. I don’t think you’ll find a new bike using it. Unfortunately all the standards are moving targets and their applicability to unicycling varies.
ISIS is a pretty big compromise for unicycle cranks since we can’t really implement a crank stop properly, which forces us to mess around with spacers. But engineering something new is a pretty big project and I don’t know if anyone is working on it.
(While we’re at it, can we settle on inboard vs. outboard disc rotors as a standard?)
Coming back to the original question. There is: Q-axle. Which is actually not a new standard, but a copy of the crank/axle connection used by Shimano since many years in the bike industry.
I have been happy with Q-Axle: Why changing to Q-Axle? – QU-AX EN
Me too. I like it. Let’s hope they decide to keep this system for a while. I think it’s the better system for all disciplines except Flatland/Freestyle. The Q-Axle system makes it a little difficult to design a nice crank for crank rolls. They do offer a thing called Rollmops to add some surface for your feet, but the crank is not round and still shaped a bit like a cam. I don’t know how that translates into “rollability” of the cranks. I’d think that a perfectly round ISIS crank would be be better for that.
1 Like
Qu-ax should develop a 125 mm wide Q-axle hub with 32 holes so that I could replace my ISIS-based Hatchet wheel with a Q-Axle alternative.
1 Like
Q-Axle hubs are creaky and their bearings are very weak
only with wrong assembly
I don’t agree
125mm, yes +1 here.
And a 36h hub without disk brake…
like this?
Regarding creaky q-axle hubs: I’ve seen them creak a bit with people that I think of as mechanically competent too. If the teeth on the hub or crank end up slightly small, there can be movement, and where there is movement, there might be some creaking. As far as I can tell, cleaning and (re-)greasing generally seems to help in almost all cases, with some riders (or sets of cranks, I’m not sure), needing to do it more often then others. What I don’t like about Q-Axle is that you can’t rotate the crank on the splines, which I like to do to rotate the rim. I like to think that rotating the point where you land jumps on might stop rims becoming oval shaped.
I think the short summary is: if splines have to be able to be installed by a consumer with basic hand tools, you’ll can’t choose a fit that guarantees being absolutely creak free 100% of the time. If this was an industrial application, you’d choose a good tight fit and install the cranks with a press and heat. Most people don’t have a press that fit’s a unicycle in it at home.. Isis tries to solve that with a conus, q-axle/hollowtech with clamping, which I think is equally valid.
With both Q-Axle and ISIS I haven’t seen:
- Catastrophic failures (of hub interfaces, some cranks still break at different points)
- Either of them having really large scale issues. Yes, some people appear to have some issues with ISIS cranks, and some do with Q-Axle, but in both cases, it appears to be less than 1% to me.
1 Like
I think the issue on Q-axle is not the connection of crank to axle. This has been proven to work on thousands of bike connections as well.
To my understanding it is the hub itself. As it is a 2 piece design (alu hub body, steel axle) it needs to be pressed together. Those more than one piece design hubs did creak on older ISIS hubs as well. As a result Nimbus and KH have changed to one piece steel ISIS hubs. Those hubs do not creak anymore.
1 Like
Yes! And like that.
Nice. That just entered high on my wishlist.
I’ve been wondering if it would make sense to build wheels stronger in that orientation.
Zero experience with Q-Axle interface, but I rode a Profile setup from 2003-2016. It pretty much always creaked. Profile used what I believe was a 45-tooth spline, which means lots of small teeth.
After being reassembled, or maintenance/re-greased, it would be quiet for a while, which would be nice for 2-3 ride, but that would be it. Going up a hill (or down), you could always hear me coming. On the flats it would be a lot quieter because of less force being applied. Anyway, that may be similar to what some Q-Axle riders have experienced. Follow the advice above if yours creaks.
In any case, same hub and no failed cranks (I used different sizes) for 13 years with no breakage. Not even close. My old Wilder was a great Muni, cutting edge when it was new, but no ability to add a brake without major surgery, so I finally upgraded…
I wonder if you wore some slop into your crank - hub interface.
I’m still riding my Profile setups – 20" trials and 24" muni – since the early 2000s and they still don’t creak.