Anyone got a pic or diagram or link of how/if the washers between the fork and adapter, and adapter and calliper, and calliper and securing bolt, should be set up please?

I want to be sure I have the calliper correctly positioned relative to the rotor, there are about a gazillion possible combinations.

Thanks.

1. Place the adaptor flush to the fork.
2. Place your conical washers between the adaptor and calliper (with concave part on the adaptor side).
3. Place calliper against the conical (convex washers) – then bolts

Never used ANY conical washers on my 3 Shimano setups.
If the fork is PM and the Caliper also PM, no washers are needed anywhere.
The Caliper should be centered with the rotor in the middle of the slot in the caliper(pads removed).
Dont use the pistons to centre the caliper, as this rarely works.

Thx folks. My adapters are Avid (but that shouldn’t matter, Postmount +20mm is the same for everyone I’d assume).

Washers are needed here, otherwise the calliper is too close to the wheel to accept the rotor. Have done as per Binno, it looks fine. I also had washer (a mm or 2) between the adapter and the fork, that was pushing the calliper a little further out and it didn’t look like the rotor to pad overlap was optimal, it looks better now.

Probably being a little finecky, but I think engineers tend to design things to work best one way so that’s the best way to do it.

Perthmtb, thx but you link not working for me.

“Dont use the pistons to centre the caliper, as this rarely works.”

I’d agree but it seems to have worked for me in this case, and is how the manual says to do it.

Avid adaptors will need to be used with the conical washers between the adaptor and caliper, otherwise its only about +15mm without them. It would have helped if you’d included this information to start with!

I stand by my advice about not using the pistons + pads to centre the caliper. It will work when everything is brand new and clean, but sticky pistons can bugger this method up. Much more reliable to do it by eye.

My adapters are Avid (but that shouldn’t matter, Postmount +20mm is the same for everyone I’d assume).

Well, no. Avid uses cup washers between adapter and calliper, so depth of their adapter accounts for that, whereas Shimano don’t – so ignore diagram I put up above as its for Shimano adapter only.

Never used ANY conical washers on my 3 Shimano setups.
If the fork is PM and the Caliper also PM, no washers are needed anywhere.

You’ll notice that on the new-style Shimano 180 adapter (as in diagram above) there is a wider bit on the top than on the bottom. This makes the calliper at a slant to the horizontal plane of the original post mounts, and means the bolts don’t go in perpendicular to the callipers. The cup washers are there purely to compensate for this and should be used with this particular adapter.

Yeah you have to use the conical washers with the above pictured Shimano adapter, as has been said it is asymmetrical.

OK I’ll get a Shimano adapter anyway, I’d naively assumed a Post to Post adapter would be the same for any brand. Know better now!

Ah good, another convert to the Shimano camp – winning them over one by one! You’ll be needing an SM-MA-F180P/P2 then 😉

They’re great brakes, Hope have a real fight on their hands here I hate to say.