I recently tried taking of the cranks off my 5 month old Onza 24" for the first time, after they had started to creak a little. One came off nicely but the other one got stuck after only coming off a couple of mm, before the bolt became immovable in either direction (with all my strength and an allan key - with a 3 foot long allan key and a vice it may be different). So I put the other crank back on again, and the creaking that was the cause for my original action had stopped, but there seems to be ‘play’ between the hub and the spindle. The cranks now both move about 1 mm at the end, relative to the wheel, rotating about the axle’s axis, but are solid relative to each other (no apparent problem with crank/spline interface). They give a worrying small ‘clunk’ whenever the above motion is caused. Is this something a bike shop could fix? If they can manage to get the crank back on fully and tighten it all up, would it solve the issue with the hub? I am hoping there isn’t any actual damage to the hub, after buying a fancy splined one largely due to claims of invincibility!
As a side point, after reading the FAQ on unicycle.uk.com about splines, I was still none-the-wiser as to how to dismantle the crank once it’s off the hub. “3. Remove self extraction ring (remember the thread goes the other way), the nylon washer and bolt. Clean and put aside.” How does one remove the extraction ring (assuming you know which bit it is)? The only clue I had is the two holes around the allan key socket, but they don’t do much.
Hope this isn’t too silly a post!
Hi, I’ve had problems with my Onza hub, tho with the 140 set. Never had trouble getting my cranks off, tho one bolt is slightly stiffer to turn than the other. Use Needle-Nose pliers to remove the self extracting washer if you have to. You can also buy a tool for it, your bike shop should have one. Lots of grease of some form is also good!
As for the play in the keyway, remove the entire axle from the shell and clean off the excess grease. Use some Loctite on the keyways and reinsert the axle as normal- make sure it has the same length showing either side of the shell and put your cranks back on. Leave it for about 48 hours and see how it goes!
I got this fix from the mighty John Childs when I first got the problem and it worked treat! Hope that he replies to your thread too, he seems to know a hell of a lot about this sort of thing!
If the keyway is slipping you can try doing the Loctite treatment. You have to press out the spindle, fill the keyway with Loctite sleeve retainer, press the spindle back in the hub, let the Loctite cure, put the cranks back on and go for a ride.
There is no guarantee that the Loctite fix will hold. My Profile hub has started slipping again after my Loctite treatment. It’s not bad so I’ll just leave it as it is until I get annoyed by it again and get the urge to fix it again.
You can see this thread: Loose Profile keyway for some more background.
If the loose keyway isn’t bothering you, you can leave it alone. It’s not likely to get much worse. If it’s creaking or if it’s bothering you then consider fixing it.
I have never messed with an Onza hub so I don’t know how the thing is put together or how to get the cranks off. I only know Profile.