Author Topic: is there a common standard for v-brake bosses?  (Read 518 times)

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
is there a common standard for v-brake bosses?
« on: May 18, 2019, 09:11:12 am »
I have a carbon fork on the M5 with caps over where the V-Brake mounting bosses would be. I'm thinking of swapping the disc brakes onto the S40 when I rebuild it post crash, which will mean V-brakes on the M5 front due to having a 26" wheel on it.

There are hundreds of the things on Amazon of course, but I've no idea if it's a standard thread?
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: is there a common standard for v-brake bosses?
« Reply #1 on: May 18, 2019, 09:24:36 am »
the most common standard fitments use a M8 or M10 thread, but there are plenty of other threads and styles (including some which are easily mistaken or have a different pitch) that have been used.

This page lists a few of them

https://shop.brake-stuff.de/en/canti-studs/

cheers

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: is there a common standard for v-brake bosses?
« Reply #2 on: May 18, 2019, 09:28:39 am »
Thanks, that site came up in my search as well.

Looks like I need to e-mail M5 to get the spec, or buy another set of brakes for the S40
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: is there a common standard for v-brake bosses?
« Reply #3 on: May 18, 2019, 09:48:52 am »
 they will have M8 ones in the LBS most likely

cheers

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: is there a common standard for v-brake bosses?
« Reply #4 on: May 18, 2019, 01:05:35 pm »
M6 according to Bram at M5.

Unfortunately on closer inspection it's a no go with current set up becasue the fork is for a 700C wheel, and the brake mounting points are right at the rim diameter of a 26" wheel, so no clearance for the blocks to pivit to the rim.
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: is there a common standard for v-brake bosses?
« Reply #5 on: May 18, 2019, 04:51:17 pm »
is it possible they misunderstood the question? Every canti boss has an M6 thread on it to mount the brake....

Sounds like you need a 26" wheel.

cheers

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: is there a common standard for v-brake bosses?
« Reply #6 on: May 18, 2019, 07:22:23 pm »
I have a 26" wheel, but it's in a 700C fork
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: is there a common standard for v-brake bosses?
« Reply #7 on: May 18, 2019, 08:22:22 pm »
oh yes, silly me; a 700C wheel then!

Have you done the obvious, i.e. tried a M6 bolt in the boss mounting?

cheers

Torslanda

  • Professional Gobshite
  • Just a tart for retro kit . . .
    • John's Bikes
Re: is there a common standard for v-brake bosses?
« Reply #8 on: May 19, 2019, 04:51:01 pm »
they've given you the thread for the bolt that fastens the brake to the boss. Which we already know.

Pull the caps and check...
VELOMANCER

Well that's the more blunt way of putting it but as usual he's dead right.