stripped hub/nut thread?

In trying to tighten a crank nut on my trials uni I’ve found that the nut just spins where it is. My first thought was it’s a stripped thread, so I tried to remove the nut to have a look, but I can’t get the nut off the hub either. It spins, but it won’t come off the thread, through either turning or pulling it with pliers. Anyone got any idea what might cause this, or any ideas for getting the nut off. A crank puller will go on the crank, but I’m worried that if the crank isn’t destroyed now then using a puller will destroy either the crank or the hub.
I’ve taken it for a ride in this state, and it held on fine, despite drops etc.

any ideas?

John

It sounds as though the threads have stripped in such a way that there is a thread on the outside holding the nut on. If this is the case your hub is toast. However, there’s no reason why you shouldn’t ride the thing until the crank really starts giving you problems. In fact, you might just weld the nut on and just ride it forever. Later on you can unbuild the wheel and save the rim.

That’s what it sounds like to me, anyway.

Try putting a flat blade screwdriver under the nut to exert upward pressure on it. Then try unscrew it from the axle using a proper sized socket spanner. It should work, i’ve done this before.
Good luck… :slight_smile:

I tried a screwdriver, but there isn’t much clearance around the nut to get it in, and the nut is still quite a way down the threaded bit, so it’s pushing across more than up. I tried removal with a 14mm socket on the end of my pedal spanner, and that makes it turn no problem, but it doesn’t go anywhere but around.
Ah well, this is the first time I looked at the nut, and I only bought the uni a few weeks ago and haven’t really ridden it properly since then, so I’ll phone my LBS and see what they say. 'course I’m back at uni now, so my ‘local’ bike shop is 40 miles away…

Cheers for the ideas

John

One thing that has a chance of working is to use the puller to pull the crank out until it is tight against the back of the nut, then remove the puller and try to screw the nut off. Hopefully the crank will have pushed it to where it can engage the threads. If not, you may be able to pry aginst the back of the crank while turning the nut and get it off.
Once off, IF there are some good threads left on the end of the hub, you could apply red Loctite to everything, press (or hammer) the crank on, put washers under a NEW nut to bring it up to the remaining threads, and gently snug it up. Let the Loctite cure and ride it.

Good luck.
Scott

had a quick go with that, but found the crank puller actually pushes on the nut rather than the crank, so that won’t work. If I can find something small and strong enough to fit between the nut and the crank puller I’ll give it a go. TIll then I think I’ll just ride it till it falls off.
I’ve got a spare hub from a similar uni, but my wheelbuilding skills aren’t up to much, and I’d like to get the crank off as well coz they seem quite good cranks. The notverylocal bike shop said I should bring it in sometime, so next time I’m home for the weekend I’ll take it with me and see what they can do. Not sure if they believe me that it’s not my fault for overtightening it, but I can always argue.

Cheers anyway.

John

Ah, of course it does. I was visualizing an arm type puller that grabs behind the crank and pushes on the end of the hub, which you probably don’t have. If you ride it until the crank gets loose, and stop before you damage the crank, then you can try the procedure. Or maybe the bike shop will help you out. Again, good luck.

John,
If you post the wheel & spare hub to me I would be happy to rebuild it for you.
PM me if you want my address etc.

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