Flat mount disc brakes and single speed

[hurricanejosh]

Having a new disc cx frame built this spring and would like to have an option for belt drive conversion in the winter.

Seems like post and tab mount road brakes are being phased out, with most distributor stock being flat mount.

Paragon only offers vertical or polydrop vertical drops for flat mount.

Are there any dropouts that support both tension adjustment and flat mount brakes? Or am I stuck with going to an eccentric bottom bracket/hub?

[David Tollefson]

Flat mount on the chainstay (or seatstay for that matter) doesn't allow for chain tension adjustment. Some one (cough cough Paragon cough cough) will need to make another option on their sliders for flat mount calipers. Otherwise go with any of the myriad of existing ISO or post mount calipers.

[hurricanejosh]

Yeah I contacted Paragon and they didn't give any implication a flat mount option was coming any time soon for their rockers or sliders. Unfortunately Canadian distributors only have flat mount (and will only have flat mount moving forward) for the TRP Hylex RS brakes I'm hoping to use. Plus, a flat mount frame can always be adapted for post mount calipers, but not vice-versa.

Thanks for the reply.

[Will Neide]

There currently are no flat mount adjustable SS dropouts. It's doable though according to my napkin drawings. I don't like the long dropout from a design perspective. I think you'd have better luck sourcing a post/iso mount caliper, despite their limited availability in Canada, than waiting for a SS flat mount dropout.

Or go EBB, like you said.

[Eric Estlund]

TRP stocks a bunch of different configurations. Sounds like the issue is more with your CAN distro. Plenty of non-flat mount options out there.

[EricKeller]

I don't see how post mount is going to go away, flat mount is a road standard, mtb's need post mount. ISO has been gone for a long time. AFAIK, they just include adapters with the post mount. I think anything chain stay mounted is going to be problematic for sliders.

Having said that, if you pick a road-only brake, it's going to be tougher to avoid flat mount from now on.

[hurricanejosh]

thanks for all the comments. in the end i decided to go with paragon's flatmount dropout assembly and a pf30 BB shell so i can use an eccentric adaptor.

[Broady]

The new Boone has an interesting solution - https://www.bikerumor.com/2017/03/30...clocross-bike/

[David Tollefson]

I saw that BR post yesterday, and it completely flew past me that it was flat mount and single-speed compatible. I'd like to see a shot of that set-up from a different angle.

[ChristianWong]

The new Boone has an interesting solution - https://www.bikerumor.com/2017/03/30...clocross-bike/

Pretty cool - I think that's the aluminum Crockett though. Nys rode a carbon Boone prototype at SSCXWC (might be confusing the acronym..) but haven't seen that frameset come to fruition.

It does, however, seem like there are a lot of nooks and crannies for mud to collect and bugger the sliding up.

[Ben Hudson]

I saw that BR post yesterday, and it completely flew past me that it was flat mount and single-speed compatible. I'd like to see a shot of that set-up from a different angle.

... and thru-axle!