Bottom Bracket size

steprog15

I've just bought a GT Aggressor 2.0 14" frame and want to find out what size BB i need.
do i just measure the internal length & height??

Chunkers1980

You need to measure the width of the shell - should be 68 or 73 mm IIRC.

You then need the correct axel width for chainline and crankset.

Check out the tech doc on their webby.

I wouldn't bother tho - buy a Deore HTII M590 crank set and your problems will disappear (if the frame's been faced)