Profile’s Tech Tip #38:How To Measure The Q- Factor For Profile Race Cranks
This Q factor measurement is based off of the photo above: of a 19mm /68 mm bottom bracket shell with a euro outboard BB kit.
In order to measure your Q factor for Profile’s cranks, with a caliper, measure the distance between the outside of the pedal bosses in either inches or millimeters (see photo below). That number is your Q Factor.
If you have another size bottom bracket shell or different style bottom bracket bearing such as an Internal Euro, Spanish, Mid, or an American BB kit, it will not matter what style or size Profile or Madera cranks you have.