its pretty much impossible to put 20v brakes on a 1.2, the best u can do is 1.8 vented brakes. i have tried it with the help of 2 engineers. the position of the 1.2 hole and the position the 20v hole need to be. will be impossible.
http://www.network54.com/Forum/15639/thread/1205076825/My+1-6+Project+log+%2APIC+HEAVY%2A
somewhere in that are pictures of my attemp
http://www.network54.com/Forum/15639/thread/1205076825/My+1-6+Project+log+%2APIC+HEAVY%2A
somewhere in that are pictures of my attemp