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So idiotically I over tightened the screws on my brake calliper into the fork post mount, this stripped just one thread from the forks post mount. The screw still goes in fine. 90% of the thread is still there.
Do you reckon that this is still safe to use?
Can you use a longer screw ?
Try a longer bolt and a bit of Loctite
Yes it will be fine. A longer bolt make make you feel safer
Would there be space in the post mount for a larger screw? If I use loctite would I be limited in making adjustments?
It’s whether I need to with only one thread missing?
It will probably be fine but it would be better to use a tap and die to recut the thread
You cannot recut a stripped thread with a tap. The metal is not there to do so.
f I use loctite would I be limited in making adjustments?
There's different strengths of loctite.
How often do you adjust the calipers?
I would try screwing a longer bolt in by hand with the caliper removed to see how much thread is left. If there's more than 10 mm, I would screw and Loctite studs into both holes and use nuts to hold the caliper on (basically, just get a long bolt of the same size and cut the head off, then tidy the end up with a file.
I would not try fitting brakes with only one bolt tightened up.
I’m not making adjustments that often, but just didn’t want it stuck in there with loctite, but fair enough if I can get a medium strength.
So I wouldn't be using only one bolt, the bolt goes in fine at the mount. It’s literally one spiral that was stripped half way down the thread.
I would definitely try and fit a longer bolt so that you're using undamaged threads near the bottom of the hole. If you can find a longer bolt, thread it in carefully by hand until it bottoms out. That will let you measure how deep the threads are. Then cut the bolt down so that it's about 5 mm shorter than the hole. Before you cut it, screw on a nut. Then tidy up the end with a file, try to put a 45 degree bevel on the end. Then unscrew the nut and that will tidy up the end of the thread.
Also, be careful if you fit a longer bolt. The two bolt holes may not be the same depth, so make sure you fit the correct bolt into the correct hole in the future if you end up with one long one and one short one.
Helicoil it, it's not difficult. You can usually order a kit with the correct drill tap and insert. You just drill out the hole slightly oversize, tap it and put the coil in. It's then stronger than the original.
And don't be so ham fisted next time!
Thanks all. Lesson learned there.
Was thinking about inserting the Heli-Coil.
At the minute the bolt is tightening up fine.
Try to get a brake adapter of the stepped, 2 pairs of screws type. This way you can do your best to recover the existing thread, install the adapter and then you can remove/install the caliper in the future without having to mess with the fork threads
It doesn't sound like anything to worry about tbh.
I wouldn’t worry, just be careful with it in future. Btw it won’t get stuck in if you use loctite. In fact using thread lock is a good way to prevent bolts seizing in place, which is why a lot of people use it on cleat bolts.
Thanks all. Think I’m just going to leave it for now. Seens pretty solid at the minute.
Might not put some loctite on just in case.
Funnily enough, I had the thread “disintegrate” when sorting my breaks yesterday. I managed to get a slightly longer bolt in, but just ordered this kit.
https://www.carbuilder.com/uk/thread-repair-kit-m6-x-1mm
https://www.bermstyle.com/installing-a-helicoil-repairing-a-stripped-fork-post-mount/