Canti post thread size?
 

Hey all -
Anybody know what the thread size is for a standard screw-in canti post? I pulled the posts off my Surly KM since I'm using disk brakes - I'd like to stick something in there to keep it from rusting.
Thanks!

Try 6mm by 1.25 pitch? [edit] I think 1.00 pitch might be the common size for 6mm bolts, not 1.25.

Unless you use thread sealant or something water can still get into the threads. Loktite (medium strength blue, so you can remove them if necessary, or green (?) which is actually for sealing threads against fluids) and stainless steel bolts ought to work though.

Thanks for the help, jeff -

Yeah - 6x1 is the standard for metric coarse. As far as sealant goes, I was just planning on using phil's grease (like I do on pretty much everything else that contacts my frame). You think that I should use loctite instead?

An interesting thing that I discovered this week: The same 6x1 thread is used in the fender/rack mounting holes on fork and dropout bosses.

I'm not familiar with "phil's grease" but a thick grease would probably work just as well at keeping water out, yeah.

NO NO NO NO NO!

M4 x 1.0 is the size for rack and water bottle braze-ons.

M6 x 1.0 is the size of the thread INSIDE the brake boss, but usually not the size that screws the boss into the frame. There is a lot of variation in these sizes so your best bet is to take the boss to a fastener shop (or maybe a bike shop, but I know I really hate wasting time searching for obscure bolt sizes for customers that they then expect for free because it is just a used bolt) to have them match it. Small plastic/rubber caps are available for this application though, that might be your better bet.

Andrew

thankyou for saying that.

Urp -
Thanks man. I thought the thread looked bigger than an m6. Small rubber caps, huh? I guess I'll just pack the threads with grease and look for some of those caps - lbs should have them, I assume.