Thanks for the answers Mark i appreciate it .
The crank situation is my main concern... Ive been running square taper middleburns for many years with a 128mm axle b.b, on frames like the gu typhoon 06 and zoo piranha 09 i have noticed on the L/H crank arm can seem to catch on the slave cylinder.. to resolve it i had to lightly grind my crank arm which felt horrible but it had to be done espically when they cost over £100 for the arms!!! lol.
As i am thinking of upgrading me arms to isis im running 170mm atm but could running 175 give better clearance and improvement to my power of riding if thats a way to put it?
Thanks Andy