Originally Posted by 55/Rad
The cheap BB I pulled with the triple crank is a 118. I replaced it with an Ultegra 109.5 and a Coda crank - a 175. But my kid is only 4'6" and I want shorter cranks. The Bulletproof crank, a double, is a 155 but uses a square taper BB. The UN53 comes in 4 sizes - 107, 110, 115 and 118.
I'm assuming the 2 smaller ones are for 2x's and the larger ones are for 3x's.
55/Rad
Cranks have specific spindle length specs.I have double cranks that use spindle lengths from 102 to 122 and that may not cover the complete range. The un53 118 was used with many shimano road triples. There were also shimano mtb triples that used both 107 and 110 square taper.