Proshift RD: Mount bolt compatibility?

Discuss light weight issues concerning mountain bikes & parts.

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Joined: Thu Feb 03, 2005 5:07 am

by dannyg1

I've got a Proshift rear derailleur that is almost unused but has the threads that thread to the frame dropout hanger stripped and just about useless. Did any aftermarket companies make compatible mount bolts? Anyone know of a source for something that'll work?


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Joined: Wed Jun 12, 2013 10:27 pm

by lotusracer

So, I just had to deal with blown-out pivot threads on my Proshift when I was putting it back on a bike. Talk about a big frown on my face!
Pivot bolt diameter:
Proshift 10.8mm, .425"
Shimano 9.9mm, .390" (I had a couple old SRP titanium pivots in my toolbox from older projects but seemingly any old Shimano derauiller could be canibalized).
The delta is .9mm or .45mm on the radius.

I went down to the hobby shop and picked up some brass tube by 'Precision Metals', marked Stock #137 7/16" x.014. This is nominally the right size and has the right wall thickness to shim a Shimano pivot bolt but not quite.

Basically all you have to do is cut a piece of this to the proper length to fit over the new pivot, and this includes supporting the b-screw aduster that sits against the hanger as this relies on the bolt being the proper diameter to keep it in place. Cut a quarter-section out of the tube so that your shim encompases 270 degrees of the tube rather than the full 360. This may vary with the kind of derauiller you're working with if it's something else. Grease it up and slide it together. I didn't bother with the o-rings but if you're stealing the bolt from an old junk derauiller that may work for you.
You can try to put a new snap-ring on the replacement bolt but it's unlikely to do any good for this configuration; you'll know what I mean when you see it.

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Joined: Sun Sep 28, 2008 9:55 pm
Location: Portugal, Lisbon

by nogueira.nuno

Not easy thing this Proshifts!!

I can buy them from you any way, dont use them but I love them :)



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