Is your rear rotor a wavy shape? No to the master cylinders upside down! You will end up with air in them, your not even suppose to put the bike upside down for long
If it is a 06 or 07 ti they will take up to 165mm. But thats with a Hope. It depends on how deep the caliper is. Just measured rear rotor on pr 07(06 ti) which has Marta's 160mm!
Come on you lazy gits, get & sign it! It only takes a minute, many big names in moto trials have signed it but not many of you at all. What have you got to lose apart from the best bit of trials land in the country bar none!!!!!!!!!!!!!!!!!