Profiles' 145mm crank arms

You will just spin like mad, I know dude who races bmx when he was a kid he had 145's still has them (he keeps everything he has) we put them on his single speed, it just failed, no pedal leverage knees never fully extended could ache after a while... not worth it...

Why anyway?

Did he change his gear ratio?

Another topic covered by Burrows in his Bicycle Design book. Anyone interested in bikes such have a scan through his book as even though he just touches on subjects it does make you think about them (crank length, frame materials, tyre sizes etc,)