Went to install a rear rack on a new Salsa Journeyer. I was threading bolts into the mounts by hand before installation to make sure everything would go in smoothly (yes with grease). First hole on the drive side – bolt threaded all the way in by hand with no problem, but all 3 other mounts are chewing up bolts when they get about half way in. It feels like cross threading, but the bolts have gone in almost a full cm with next to no resistance before that.
Silver bolt in first photo came with rack, black bolt is one of the bolts that came on the bike. You can see pretty clearly on the black bolt where the threads are mangled on the bottom half. Second photo shows where I start feeling resistance. Same issue in 3 of my 4 potential lower mounting points, albeit maybe a little deeper or shallower by a couple of threads
Thoughts?
by outofstepwtw
7 Comments
I don’t see much in the way of chewed up bolts in your hand. Are they producing any slag? You might want to get a thread gauge and check the threads on the screws and compare them to what salsa says their eyelets are. Might be a different thread pitch, but that would be odd. Also there could just be some paint in the internal threads and you are basically chasing the threads with the screw. Do the holes go all the way through? Are you hitting the frame?
These aluminium screws are soft as butter. I wouldn’t use them to mount a rack – they tend to seize and are a pain to get out. Stick with the stainless ones.
I’d wager there is some corrosion in the mounts. Happens..
Either chase them (by hand, should be quite easy) with a M5 thread cutter or just screw in a well-lubed stainless bolt *if you are sure the treads are catching*. The latter is easy to fuck up, but you can usually tell if it works or not by the resistance.
Slightly off topic but blue loktite (242 or the like) over grease for those things. Grease is fine but the loktite is better.
I don’t know what’s causing your issue though.
Looks like you may want to chase that with an m5 tap to clean the threads out again.
You may need nylon threaded nuts
Are they different thickness or is it the colours throwing me off?
Chase the threads with the correct sized tap and you should be golden.