What about where the flange has torn, the weld has split, and the axle and the flange have parted?
Well they are obviously made so they bend like this, because otherwise there would be loads more strain on the flange, no? And I haven’t read on here of anyone actually breaking the hub, so what do you have to lose?
Does anybody know if there is a warranty for the hub like there is for the frame?
This deformation doesn’t look at all like a case of strain hardening. It looks like a case of metal fatigue. Strain hardening doesn’t happen by accident; you have to be relatively precise in the level of force applied.
Strain hardening occurs whenever a material deforms plastically. There are no ‘specific conditions’ required for it to take place.
The reason a paperclip fails after many repeated bends is actually due to fatigue crack initiation, under a cyclic load. Basically you are bending the metal until a crack forms, then the crack grows with each bend, reducing the cross section of the paperclip and making it easier to bend the next time, until the metal eventually fails due to brittle fracture (the snap).
Loose.
And you don’t think the pictures posted above indicate fatigue cracking? Like, for example, the crack that’s formed? Unicycle wheels are under cyclic stress.
I’ve kept ridding mine through the bending and its holding up okay.
so to summarize the above posts, bending metal makes it harder and more brittle, though bending against a previous bend may create small cracks that ultimately weaken the metal
unless you’re forging something, of course
And now moving away from the fact my hub is all bent, do you think that it is going to be worth lacing up a wheel knowing there is that tear in the flange and that in a few places the flange is coming away from the axle, at the worse point the weld joining the hub and flange is cracked/split?
That hub looks bretty bad, the metal has snapped and it is bent loads, bending it back will weaken it and possibly make that snap bigger. Doesn’t Kris have a warrenty on his parts? Because it may be a good idea (in my opinion) to try and replace it. It will no doubt last longer, but will be weaker.
maybe, I know that you’re hard on your unis, but I don’t know how much you risk
Try and get some responses from people who have broken hubs at the flange, see if you just risk a few spokes besides the hub or if there is a chance you could lose your rim as well.
I’d like to see how this turns out, tell us how it’s going after a while.
The thing is, I can’t see how relacing the hub would have any effect on the strength. All the flanges do is attach the hub to rim, and how could the flanges themselves actually break? … strain when doing drops etc is put on the axle and cranks, rim and spokes. I suppose if your rim broke then the other end of your spokes may take some stress and break due to weak flanges? Can anybody elaborate?
I hate bending the flanges back, but its the only way I can get my spokes into or out of the flange without bending the spokes really bad.
After a few more wheelbuilds, ill be tossing the Kh hub and getting a Nimbus hub, unless Kris does something about the big chunks of metal missing in his flanges only saving a few grams of weight that I really do not think are important to be saving when it causes so much extra trouble.
I thought the holes were there to allow the flanges to bend, not just to save weight?
theyre suppose to flex a bit, but not untill they bend like that!
Well not necessarily, it’s hardly like there’s anything in place to stop them bending further than ‘‘a bit’’.
A hub flange should not bend under normal load; if it’s designed to do that, it’s a design flaw.
The cutouts were like that so that extra hubs couldn’t be made sold for a lower price by another company (summits). Sort of like a trade mark stamp to prevent counterfitting.
Sounds like a bit of a useless idea really. It can warp the wheel and damage the hub, so it doesn’t sound like a good idea to put them in to be honest.
What I am concerned about is that I bend it back, weakening it more. Then after lacing it up and riding they bend back in and the tear gets longer and more puls away from the axle and it get worse and worse and I have to de-lace then rebuild my wheel with a new hub and I wont be able to ride again.
I don’t see why someone would buy a summit hub just because it has the same drilling pattern as the KH. It seems to me like KH hubs are badly designed. And they’re a bad colour! I’m pleased I’ve got a nimbus one.
Wasn’t a guy at the start of this thread saying that the metal would be strengthened after being bent? I always thought it would be weakened too but maybe I’m wrong.
I think you should probably just bend it back and keep using it. If it breaks so much that you can’t ride with it Kris will probably replace it won’t he? He might even have a new hub out by then 