Hi all could someone give me the dimensions for the brake drum insert,I believe cast iron pipe is used?

TIA.

I found it not that simple and ended up skimming the chrome off to get a clean surface, don't over do it, I then got a Westwood cylinder liner, sized and pressed in and turned it internally to 120mm and used Kawaski brake shoes 120mm x 30mm which just fit with some trimming and adjustment, we made about 5 from 1 liner. That was a long time ago, no drawings, just touch and feel, they worked well, better than original but Montesa cota wheels are equally good

Hi, If you look on Facebook there are a few folks who will reline your hub. Or some one who can point you in the right direction.  My mate gets his done in Liverpool and the guy does them with the hub and wheel complete.

the problem with the bultaco hub is that the chrome  should have been copper etched prior to chroming, you are left with hardly any metal to remove before you seriously weaken the hub so in some cases a thin steel insert is used which  makes a poor brake. that is why I elected to go down  to 120mm  or else the cast liner would be too thin and break up as it is more brittle, it seemed the best solution and worked very well

                             Good luck whatever you do