trouble fitting rear brakes

[Mr. Viking]

I am trying to fit new brakes to a bike (Puch "Touring" of unknown age) I am refurbishing. However I have hit a dead end, as rather than a tubular rear brake mounting, there is a metal plate (this picture is upside down, you can see the tyre at the top)

The old brakes had a square face to bolt on to this

but the replacement has a rounded mounting.

Any ideas on how to fit the new brakes, or should I give up and use the old calipers?
Note: The new clipers do not disassemble, they seem to have been press fitted, so I can't just remove the mounting on them, unless I am missing a trick

[531colin]

your new brake is a new one on me.
normally, they have a bolt throught them, with a washer (that you can discard) shaped to fit the brake bridge on the frame.
eg....http://sheldonbrown.com/calipers.html

[tyred]

The new brake mounts the same way as the Mafac centre pull on my old Peugeot touring bike (Is it a French made caliper? My c1970 Peugeot is the the only bike I have even seen this design on). It requires a circular brake bridge and the bolt passes through from the top, through the mudgaurd (if fitted) with the nut underneath next the wheel.

From digging around the net at the time I got mine, I think the idea is that this type of mounting prevents the issues you can sometimes have with centreing the caliper.

My guess is that it is possible to remove that piece and be left with a standard caliper. I know it can be removed from my Mafac.

[Mr. Viking]

(Is it a French made caliper? My c1970 Peugeot is the the only bike I have even seen this design on). It requires a circular brake bridge and the bolt passes through from the top, through the mudgaurd (if fitted) with the nut underneath next the wheel.

it is French. it's a CLM brand, which I think are no longer produced. I guessed that was how it should fit. The fitting is attached by a combination of what looks like pressing and aluminium welding. It is firmly in place. I suppose this leaves me with two options;
use a different caliper;
remove the brake bridge and replace with a tubular one.
I think I'll just fit the old caliper for now. Pity, the set I bought are quite nicely made, but I'm sure I'll find a use for them

[Mr. Viking]

your new brake is a new one on me.

it was new to me too, I thought I might have been being stupid because i hadn't checked the type of fitting when I bought them, but it seems I was just unlucky

[tyred]

My guess is someone with an old French made frame would probably give you a good price for that caliper as calipers with that mounting are not that easy to find.