Ok, so I need to upgrade the disc brakes on my winter road bike, as the ones factory fitted are, well, worse than useless..

But I’m unsure if they’re Flat mount or post mount on the front?

Pics are here in the review:

https://www.bikeradar.com/road/gear/category/bikes/road/product/cannondale-caad-optimo-disc-tiagra-review-51230/

Cheers all..

All you need to know is here

Looking at the images, definitely post-mount.

Looking at the images, definitely post-mount.

+1

Flat mount has a tiny triangular shaped calliper and mounts ‘flat’ to the frame. Post mount has the holes further apart and the calliper sits in between them on the ‘posts’.

Flat:

Post

Cheers All.

it would appear that it’s post mount on the forks and Flat at the rear stays.

Joy. 😩

it would appear that it’s post mount on the forks and Flat at the rear stays.

My road bike is like that. If you get a set of post mount brakes you can get a flat mount to post adaptor for the back end.

Same as my caad12. The frame is new and current but they’ve carried forward a fork from the previous model. Genius.

My road bike is like that. If you get a set of post mount brakes you can get a flat mount to post adaptor for the back end.

I’ve just ordered a Flat and a Post mount from Merlin..

Ah well..

Again, many thanks all, glad its not just me then!

Not necessarily – from my reading / research the key difference is that flat mount calipers have the thread in the caliper so the bolt goes through the frame/fork and secures in the caliper.

However, partly because of design and partly because of having tooling already set up for forks, most forks still have the threads built in and hence flat mount front calipers are attached via an adaptor, so the adaptor bolts to the fork and the caliper then has bolts through the adaptor into the caliper.

You can see that on the picture in TINAS post (except you can’t see the bolts because they must be either small / flat headed or recessed into the adaptor) but you can see the bit for the ‘receiving’ thread on the bottom of the caliper.

Flat mount rear

What i don’t know is whether it’s possible to convert a post mount rear mounting to take a flat caliper in the same way as the front – I don’t think so but maybe someone knows differently.

What i don’t know is whether it’s possible to convert a post mount rear mounting to take a flat caliper in the same way as the front – I don’t think so but maybe someone knows differently.

It’s probably possible but the adapter would be hideous. The alignment of the mounting bolts relative to the disc on flat and post mount is nearly 90 degrees apart so the adapter would have to correct for that.

What i don’t know is whether it’s possible to convert a post mount rear mounting to take a flat caliper in the same way as the front

Read the article that bluebird linked to above

https://www.bikehugger.com/posts/road-disc-brake-tech-flat-mount-vs-post-mount/

Same as my caad12. The frame is new and current but they’ve carried forward a fork from the previous model. Genius.

Used up old stock hoping no one would notice/didn’t care enough.  It’s the reason I didn’t buy a Cannondale, that and a non bolt through rear axle.