Flat mount for brake calipers which are not flat mount

https://www.merlincycles.com/trp-flat-mount-to-post-disc-brake-adaptor-89957.html

And possible some of these..

https://www.merlincycles.com/trp-flat-mounting-bolts-300398.html

Thank you, ordered looking forward to fitting them.

Looks like these are not compatible. The fixings are 70mm apart but on the fork it is 80mm. I have spoken to a bike shop and they say the only choice I have is new flat mount calipers.

Maybe I am missing something, any thoughts / advice would be greatly appreciated.

Thank you

That seems very odd. The front and rear flat mount spacing is different, did you buy one front and one rear adapter? The standard says 70mm gap between the holes in the front with no variation. A new caliper is not likely to help here as a front flat mount caliper always sits on a adapter and you'll have the same issue as that will be 70mm spaced.

Shimano, Aztec and others make adaptors to suit.

https://www.freewheel.co.uk/shimano-disc-adapter-for-post-mount-calliper-for-flat-mount-fork-for-160mm-rotor-smmaf160pd

https://www.freewheel.co.uk/shimano-disc-adapter-for-post-mount-calliper-for-flat-mount-frame-for-160mm-rotor-smmar160pd

Aztec and others are cheaper, but require the mounting bolts. Shimanos come with them.

The op has already bought similar adapters.

TRP I think come with bolts, certainly did for the flat mount 160 adapter I just bought (both sets of bolts). Shimano on the other hand don't for the front, I think they expect you to get the adapter and bolts as part of a kit with the front caliper so separately they come as individual parts. Rear is different as it's a step up kit that's not bundled with a caliper.

Op might be worth adding some pictures of your forks etc. does the rear fit with the adapter?

Op might be worth adding some pictures of your forks etc. does the rear fit with the adapter?

I use Shimano SM-MA-F160P/D front and SM-MA-R160P/D rear adaptors to fit post-mount SLX 2-pot calipers on my flat mount equipped Cascade. Not sure if it's a Cotic-specific thing, but the above adaptors result in needing to use +20mm rotors, i.e. I run 180mm front and rear using this adaptors, despite the 160 bit in their description.

80mm spacing is really odd? Presumably the fork comes with a specific adaptor to take a FM caliper as the ones supplied with FM brakes are for 70mm spacing. If so, you could potentially fit a rear FM-PM adaptor on the supplied adaptor, though it wouldn't be pretty.

You sure yours isn't Post Mount? 74mm spacing. Never seen an 80mm spaced mount.

I think it'll depend in which model year crockett the OP has. The current version is definitely flat mount but older ones were postmount. Always the odd possibility of a half an half (FM frame and PM fork). I've seen this on framesets from other brands.

Thanks all for your responses, late response due to work commitments.

It turns out.... Outside of being a fool, I was indeed trying to fit the rear adapter to the fork and when I tried to fit the front adapter it fitted and guess what, the rear adapter fitted on the rear! Being a gentlemen of a certain age, I now need to accept that I should wear my reading glasses, as this would have helped.

I wholehearted apologise for causing confusion. I really appreciate your help and am super happy that the adaptors and the calipers fit.

This is my favourite forum for when I am stuck or unsure as you provide such useful advice.

Thank you and sorry.

P.s. It is a 2024 Trek Crockett frameset and yes the older frameset was Post Mount on the fork.

Thanks all for your responses, late response due to work commitments.

It turns out.... Outside of being a fool, I was indeed trying to fit the rear adapter to the fork and when I tried to fit the front adapter it fitted and guess what, the rear adapter fitted on the rear! Being a gentlemen of a certain age, I now need to accept that I should wear my reading glasses, as this would have helped.

I wholehearted apologise for causing confusion. I really appreciate your help and am super happy that the adaptors and the calipers fit.

This is my favourite forum for when I am stuck or unsure as you provide such useful advice.

Thank you and sorry.

P.s. It is a 2024 Trek Crockett frameset and yes the older frameset was Post Mount on the fork.