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need advice on a stripped deraileur adjustment screw

Anyone have any advice for moving a stripped adjustment screw on the front deraileur? I can't get it to move with the screwdriver and it is down low enough that the one time I was able to get the vice grips to lock on it the seat tube was in the way of actually turning it. I'm hoping not to have to drill it out. Thanks.


bd
2011-06-09 14:47:29

i would imagine that taking it off the seat tube would be easier than drilling it out. if you've got something like a dremel, could you cut a new slot for a screwdriver to bite into?


hiddenvariable
2011-06-09 14:54:40

Dab of 2-part epoxy, JB Weld, or some such, and another small screw with the tip ground down for more surface area?


It'll look goofy, but you should only have to back it out once to replace...


reddan
2011-06-09 14:55:13

can you get to the other end from the bottom with a needle nose pliers? You may have to remove it from the frame.


dmtroyer
2011-06-09 14:55:18

If you ask a certain cool gruff bicycle shop owner on Penn Ave, he has a tap set you could potentially use to drill into it if all else fails


sgtjonson
2011-06-09 14:58:09

If I understand correctly, the screw is frozen, probably because it's steel in an aluminum thread, and you've chewed up the Phillips head so badly that the screwdriver won't engage it any more. Is that right?


I would try penetrating oil, then put the whole thing in the freezer for four hours, put in in a vice and grab the head of the screw with your vicegrips while heating the derailleur with a hair dryer on high.


If that doesn't work, I'd try using an EZ-OUT (or other "screw extractor") -- if you can find one that small and have a drill press and clamps sufficient to hold everything in place and don't break it off. It's fiddly work. Then do the cold/hot thing again.


If you drill it out, you're definitely going to have to tap in new, larger threads. If it's not a super high-end racing derailleur, I'd guess that wouldn't be a problem.


welding a nut on the end of it is a standard tactic on bigger bolts, but I've never seen an arc welder that small. I would be impressed if JB-Weld was strong enough. Try it and let us know.


lyle
2011-06-09 17:34:17

my understanding is that it is not frozen... just stripped and down too low to get a grip on with pliers. but bd can answer more authoritatively :-)


dmtroyer
2011-06-09 17:59:07

OIC. It turns, it just doesn't back out? In that case, jb weld is probably fine, or just a bit of bubble gum on the end of the screwdriver.


lyle
2011-06-09 18:03:09

I was envisioning a screw that had simply been stripped out, and couldn't be turned because the screwdriver couldn't get a grip.


If it's actually frozen, I agree that JB Weld is unlikely to do the trick.


reddan
2011-06-09 18:10:32

Thanks for the ideas. If it's not completely frozen it is at least very hard to turn. The head wasn't in great shape when I started trying to turn it and it has gotten worse through my efforts.


bd
2011-06-09 19:04:55