Stripped axle threads and bolt

I haven’t been able to find a thread that deals with this issue so I had to start one.

I overtightened one of the axle bolts on my Torker DX wheel. When I unscrewed the bolt, a little more than an 1/8" of the threads of the bolt were stripped. It was a little rough unscrewing it from the axle too. I looked inside the axle with a flashlight and saw an area inside the axle that was stripped, matching the bolt.

I have a new bolt (the stripped one wouldn’t thread back in to the axle), but will screwing in the new bolt cause the bolt to strip, or worse, further strip the threads inside the axle?

Hopefully the description of the axle and bolt is clear, but let me know if it need clarification.

Also, please don’t tell me to ditch the wheel just because it’s a 4 year old DX.

Thanks!

Look carefully inside the axle again and use a probe of some sort to find out if the material you see is from the bolt. If that is the case you might be able to just dig it out. It depends somewhat on whether the bolt or the axle is the harder material. If it is not material from the bolt you might be able to borrow or buy a tap and chase the threads in the axle. A bike shop should be able to do this for you if you are uncomfortable with the idea. A common size for the axle and bolt threads is M8x1 but check to make absolutely sure.

There doesn’t seem to be any loose or excess material- the axle is just kind of rounded off, without threads. So is the bolt, so presumably the two metals were equally hard. Since it’s such a small area and it’s only lacking threads at the back (the rest of the threads are undamaged), is it a bad idea to just screw in the new bolt?

Is this a splined axle or square? If square then you might make sure the crank is well set down on the axle before tightening the screw. In other words it needs to be pounded on with a rubber mallet or wood block and hammer before putting a load on the threads. Tighten one eigth of a round, pound a little, tighten, pound, repeat. Back the other end of the axle up with a wood block on the concrete pavement. Others may have better methods.

1/8 of an inch of threads is not enough engagement before having a lot of tension on the bolt.

There may be a metal burr or something in the crank or flat of the axle that prevents a proper fit up.

I think this picture should clear up what I’m trying to describe. Of course the picture isn’t to scale.

On the right is the axle bolt and on the left is the axle.

The black shaded areas on the bolt and the axle represent the stripped or rounded out threads.

The area with the diagonal lines on the bolt and the axle represents the undamaged threads.

I think this is obvious but for clarity, on the axle, imagine you’re looking at a cross section and those lines and the shaded area are on the inside of the axle.

Also, I have cleaned out any metal burrs and junk like Doug suggested I do.

From your drawing it looks like the threads that are wonky are at the end of both the bolt, and the axle. If that’s true, then you should be able to chase the threads in the axle to clean them up. I would bring them to your LBS and have them take a look at it. They may be able to chase the threads for you on the spot.

Jtrops is correct. A bottom tap is what is needed to clean that properly. But you might want to go to a bicycle establishment rather than the Local Boot Shop. :smiley:

Thanks, problem solved.