Avid post mount adapter needed

fd3typer2

Hi all,

I had Elixir 7 brakes front and rear on my bike, both post mount with 180mm discs. I have just bought a pair of Elixir Trail 9 brakes which came with 200 and 180mm discs. Today I decided to install the callipers on the existing discs, thinking that they would be a straight swap (I didn't think about ordering and post point adapters in advance for the larger disc).

After mounting them, I noticed that the pads sit 5mm outside the edge of the disc, as though the disc is too small or the adapter is spaced out too far.

The instructions say I should be using a 20p adapter for the 180mm discs, and a 40p adapter for a 200mm disc.

Sorry I'm new to this and it's all quite confusing, can anyone tell me specifically where I can buy the appropriate adapter for the 180mm rear disc, and for the new 200mm front disc.

I've attached a few photos which might make a little more sense!

nicklouse

Page 55

http://cdn.sram.com/cdn/farfuture/VZCoZ ... _rev_a.pdf

nicklouse

No the big question are your brakes CPS fitting or standard?

I guess standard.

fd3typer2

Looking at Page 54 now..

As the new callipers sit 5mm out, yes it would appear my mounts are "Standard"

But the original callipers were using the CPS washers. Wouldn't that mean the mounts are CPS??

Anyhow, does this mean I simply do away with the washers?

Thanks

cobba

Avid makes CPS calipers and non CPS/Standard calipers.

Adapters aren't CPS specific, you can use them with CPS calipers and non CPS/Standard calipers.

CPS calipers need the CPS washers between the caliper and the post mount or between the caliper and the adapter.

Non CPS/Standard calipers do not need CPS washers between the caliper and the post mount or between the caliper and the adapter.

If you use CPS washers between the caliper and the post mount or between the caliper and the adapter with non CPS/Standard calipers, the caliper will be packed out too much and the pads will overhang the rotor, this is bad.

The Avid Trail brake is a non CPS/Standard brake caliper.

* The non CPS/Standard brake calipers still use the CPS washers between the bolt head and the brake caliper when the 20mm Post adapter is used, this is so the bolt will tighten down on the brake caliper properly.

fd3typer2

Thanks Cobba, a clear and very useful reply! Now I understand. I'll do as you mentioned to get them working with the pair of 180mm rotors meanwhile.

Would anyone possibly be able to point me in the right direction to buy a 40p spacer for the front 200mm?

nicklouse

The mount is no different so anywhere that does them does not even have to be an avid one.

The 40 is the diameter difference and P is post mount.

Direct mount is 0P is a 160 disc or 20P if it is a 180 disc and direct mount.

As you need an adaptor for a 180 disc you have a 6inch post mount.

cobba

fd3typer2 wrote:

Thanks Cobba, a clear and very useful reply! Now I understand. I'll do as you mentioned to get them working with the pair of 180mm rotors meanwhile.

Would anyone possibly be able to point me in the right direction to buy a 40p spacer for the front 200mm?

You'll probably need shorter bolts when you remove the some of those CPS washers.

Plenty of shops sell the adapters, some shops call them 'CPS Adapters' but they aren't CPS specific, the name probably dates to when Avid only made CPS calipers and didn't make non CPS/Standard calipers.

Some shops list the 40mm Post adapter as 200mm front/180mm rear, the 180mm rear only applies to 140mm post mounts, if the frame has 160mm post mounts the 40mm Post adapter is used for a 200mm rotor.

http://www.merlincycles.com/avid-caliper-mounting-brackets-55672.html
http://www.chainreactioncycles.com/avid-disc-brake-adaptor-hardware/rp-prod108155

fd3typer2

Ordered from Chainreaction. Says "SS Bolts" so hoping it comes with bolts!

Thanks once again for your help.