Canti to U Brake Retrograde. Is It Possible?

[Thame Game]

I have a Peugeot hybrid frame and forks with canti bosses.
I also have a nice set of front and rear Campag U brakes.
Is there any modification I can do to the bosses or brakes that will allow them to work on 700c rims?
The frame has just been powder coated, so it's a bit late now for a complete boss removal and swap.

 

[Frankenorange]

to get u brakes to work with canti/V bosses you will need a big horseshoe plate mounted on the canti bosses and bosses for the U brakes mounted on that.
Going from 26" to 650 or 700c with cantis/V's is a common mod and you can buy adapters for not a lot, or try and find the horseshoes that Mavic made. The latter are rare and can be pricey.
U brake bosses are much higher up the seat stays than canti bosses so a custom adapter will be required. Easy to make though if you have a workshop to hand, or want to pay someone.

 

[Thame Game]

to get u brakes to work with canti/V bosses you will need a big horseshoe plate mounted on the canti bosses and bosses for the U brakes mounted on that.
Going from 26" to 650 or 700c with cantis/V's is a common mod and you can buy adapters for not a lot, or try and find the horseshoes that Mavic made. The latter are rare and can be pricey.
U brake bosses are much higher up the seat stays than canti bosses so a custom adapter will be required. Easy to make though if you have a workshop to hand, or want to pay someone.

That all sounds very do-able. It is a project bike with a difference anyway, so let's see...

 

[Thame Game]

I should've added that the frame is not a conventional 26" wheel mountain bike.
It is a hybrid with road bike wheels.

 

[Frankenorange]

That would make the horseshoe smaller. Be a little less flexy and a bit lighter.