This is my first post on here, so a big hello to everyone first 🙂
I've just taken delivery of a new frame which I'm building into a lightweight XC bike. The bottom bracket tube and head tube are both ready faced, but the rear caliper mounts are annodised like the rest of the frame, and are not faced.
The caliper mount on my new forks is ready faced.
Should I be getting the rear mounts faced too? The manufacturer of the frame said it's not necessary, but I would have thought from an engineering point of view the mounts should be faced so that the bolts can work in traction rather than shear.
I don't pretend to be an engineer and might be talking rubbish... Do other people get theirs faced?
Nope, never have.
Calliper bolted on loosely, pull & hold lever, tighten calliper bolts, ride.
I have a facing tool, so all of my brake mounts are faced. with anodising it probably wont matter but thick powder coat can cause alignment problems.
Yes, on the frame, particularly if it's powder coated. Get even pad wear, less noise and better lever feel.
And apologies sofatester, that's not the way to centre your pads. Watch this video on the Hope site to learn how to do it properly
http://www.hopegb.com/page_mep_force_38.html
You'll get much better performance and much, much better lever feel.
what brakes will you be running? If it's anything Avid, I'd say no as there's so much adjustment in the tri-align system. If it's an IS calliper spaced with shim washers, then yes.
If you want your brakes to work to their full potential, then yes(unless you've got Avids with the wibbly washers).If you've never faced a mount before, you'd be surprised how far out a lot of them are, some calipers sitting a good five degrees out(some rotors even touch the top of one pad, and the bottom of the other).Try it first though, assemble it all, and if you can get both pads to clear the rotor evenly, and hit it dead square at exactly the same time then you'll not need to bother.
Tektro IS mount brakes
I was considering strength, rather than alignment, when asking the question though. I understood that two faced surfaces will grip each other, therefore not placing shear loads on the bolt. I'm not really sure what sort of loads we're talking about, so perhaps it's not important in this application.