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Old 04-06-2013, 03:22 PM
cmbicycles cmbicycles is offline
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Join Date: Apr 2012
Location: Richmond, VA
Posts: 4,637
The threads were perfect on the new bolt, not likely perfect anymore. Sounds like the threads in the frame need to be tapped. When galling occurs the two surfaces pick up/transfer material from one surface to the other. The once smooth surface in the frame is no longer smooth, it likely has some ridges or bumps on the surface from picking up material from the old bolt. Sometimes with the galling they create a sort of anti-reverse burr, like parking lot spikes so you don't back up, it ramps up in one direction so it goes in smooth but is a bugger to get out.

I doubt it is so bad that it needs a heli-coil or similar, so tapping is the best bet. Being ti, I am sure you are aware, it is prone to wrecking taps so lots of good cutting fluid suitable for ti. After tapping so the tap goes in and out easily, try threading in the derailleur alignment tool, as I believe they have a hardened bolt.

You can try Teflon tape along with the copper anti seize when reassembling. In theory the copper particles in the anti seize are supposed to fill the gaps so the metal doesn't gall, the addition of the teflon couldn't hurt. Other industries use silver coatings on bolts prone to galling, or there are nitride coatings and anodizing options, but likely not economical.
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