Q-Axle questions

I have read that the Q-Axle is lighter and stronger and has advantages over the ISIS standard. I have read a few problems reported with a few unicycles equipped with them. I have also read that there can be problems with ISIS due to pedals not fitting accurately, becoming loose etc.

I read on the QUAX site that they were the first to use ISIS on unicycles and consider the Q-Axle to be a step forward. Is the Q-Axle an improvement and the way of the future?

I have not found many comments on them here after using the search function. Went to my local unicycle shop to check out the Kris Holm models, and their supplier sent them the last generation of rims with holes last month instead of the current version with the new rims. I like the construction and quality of the KH unis, but the external brake bugs me even after looking at it in person.

I do see positive comments on the QUAX being tough and well made. If I go for a braked Muni in the future, would probably want one with an internal brake and rim without holes. So I was looking for more feedback on the Q-Axle and QUAX Muni’s. A lighter hub makes more sense to me than a rim with holes in it.

I suppose that in the distant future, would be better off to go with the KH if I ever want a geared hub. I think the KH has a wider rim for the larger wheel sizes, which I am not sure if they would fit in the QUAX frame. At this point I like the idea of a wider rim and fatter tire.

Sorry for kind of being all over with this initial post, too much coffee and not enough sleep. Main question should be on getting good info on the Q-Axle. Any brand other than QU AX using them?

Hi Up Rite,

as of today, the Qaxle is a Qu-ax only technology and it is available only on their QX line of unicycle (the top end ones). It has an impact on the parts selections even though they offer dual holes cranks in several lengths.

As for the interface itself, I heard that it exists in the bike world so it may be strong enough for a unicycle. In the past, there was other sort of splined interfaces (mostly from the BMX world) and it worked fine. Usually the complaints back then were about weight and price.

On the upside, you will be happy also with the latest KH uni that boast a new slightly wider rim without holes to be tubless ready.

If you just want a uni and like the QX ones, you will still have a nice uni to ride around. Whatever uni that can fuel your fun is a good uni :wink:

What is the correct way of removing and refitting cranks to the Qaxle eg tools and torqueing of bolts do they require any maintenance.

The cranks come loose. This takes time, however. I think it is more a function of the material of the cranks, than it is a problem with ISIS. My understanding is that the metal used to make the hub interface is stronger than the metal used on the crank interface. At a certain point, the crank interface gets opened up, and the cranks have to be re-installed with skinnier spacers, which accommodate moving the cranks to a wider part of the taper. I have a pair of cranks (170mm QuAx) on my 26" muni which bottom out against the bearings without any engagement of the taper. The ISIS interface keeps functioning under these conditions, but the crank bolts are likely to come loose, maybe because of the wiggle in the cranks. The problem is more pronounced on the crank corresponding to my dominant foot. I have a pair of Impact Eiffel cranks on my 20". I have not needed adjust the spacers, even after a lot of riding. I don’t lubricate the interface, and there has been no noise in the interface. I think the metal is stronger on the Eiffel cranks.

The biggest criticism I’ve heard of ISIS is that the angle of the taper is not pronounced enough.

Has anyone here that did a custom build from scratch consider or choose the Q-Axle over an ISIS set up? If so, why or why not?

Why do you think it’s a problem? Most of the issues people have with them are purely theoretical, and don’t result in real problems in practice.

The disk has better protection inside the fork, which in some circumstances could be a problem if it lands on something depending on where the pedal is pointing at the time.

The disk inside the fork keeps the baloney slicer a little further away from possibly cutting the foot or leg if something goes wrong. I definitely prefer the disk to be a little further away from my foot and lower leg than closer.

Overall, the disk and your foot and leg are probably both a little bit safer with the disk on the inside. A little bit, can be the difference between a break in equipment or an injury or just having a close call. Falling down a lot is part of unicycle riding, and it only takes one UPD to go a certain unplanned way and ruin your day.

It is extremely hard to fall on the brake disc even externally. Falls rarely result in you crashing straight down onto your unicycle, for muni they are mostly you hitting something the unicycle not making it over and throwing you off the front. Huge numbers of people ride external brake discs with zero issues. Its also pretty difficult to break the discs in falls, I would imagine if you are likely to break it in a fall with an external disc you are also probably going to with an internal.

(I am fairly sure) that using the internal brake discs means using 125mm width hubs exclusively which many don’t like because of wide q angles. and internal disc brake means a dished wheel build which some dislike.

I am not too keen on the dished wheel build. I like things as symetrical and as simple as possible. The external disk is definitley simpler and more symetrical. That is also good to know, that the internal brake also affects the width Q and probably other things.

I suppose that as you and others have said, the safety risk etc. is probably very small with the external disk. People that have this set up do not have known problems with it except for that one incident on the Italian site.

You are probably right, except for that incident where the skill saw like brake from QU AX was put on an external system resulting in a pretty nasty looking injury. Otherwise, nothing else reported that I am currently aware of injury wise. There is a post somewhere of the external disk system getting broken during a ride making it unuseable. I do wonder if these supposedly rare incidnts would have been avoided if the same thing happened with an internal disk.

At some time in the future completely different more advanced braking hub and crank systems will probably replace ISIS and Q-Axle Shimano set ups.

I wouldn’t personally use a saw rotor - but that goes for internal or external (you’re unlikely to hit the disc with your leg either way, but with a normal rotor it wouldn’t injure you). As discussed, there’s a good chance these incidents would have happened with an internal disc.

Dishing of the wheel probably isn’t an issue for most of us either, but people doing big side hops do put a lot of side load on the wheel and it might be important for them. Personally I have an external disc just from convenience, as I didn’t have to get a new wheel (with the added bonus that I’ve been able to use the same setup on both my existing 29 and 26 inch wheels).

Only on 32s, 36s and fatties (Oregon, Hatchet). All the other Oracles for example use 100mm hubs.

I believe Qu-Ax uses 100mm hubs for all their unis with inboard discs, even the 36ers. Not sure what that’s like in the real world but presumably they tested it.