Pedal Thread Adapter



This adapter provides the option of measuring from the drive-side pedal threads rather than the bottom bracket. Because VeloAngle's 648 – 1158 mm measurement range is offset by the crank arm length, the adapter allows measurement on the smallest frames.


  • Pedal Thread Adapter
  • M8 x 1.25 class 8, zinc-plated nut (13 mm wrench)


  • For 9/16” x 20 pedal threads
  • Adapter wrench flats same as nut (13 mm)


  • Adapter: Machined 303 stainless steel
  • Nut: zinc-plated hardened steel


9/16 x 20 is the pedal thread standard for any modern bike. Exceptions are some older European bikes. Threads are conventional righty-tighty, lefty-loosey and can only be installed on the drive (chain) side.

In addition to providing an option for those that prefer measurement from the pedal axis, the Pedal Thread Adapter allows measurement on small frames where BB/Saddle or BB/Handlebar measurements less than 648 mm are required. Moving the reference point from the crank axis to the pedal thread reduces the effective measurement by the length of the crank arm.

Measurement from the pedal requires that the crank arm is aligned with VeloAngle. To prevent resistance when rotating the crank arm, the chain should be disconnected or dropped during use.


As the maximum allowed clearance between the pin and mating bushing is 0.0025” (0.063 mm), the far end of VeloAngle will remain aligned to the pin at throughout its measurement range.

While the crank arm must be aligned with VeloAngle, accuracy is not highly sensitive to how precisely the arm is aligned. For example, if the VeloAngle and the crank arm were misaligned by 1 degree (which would be clearly visible) the error on a 900 mm measurement would be 0.7 mm.

An option to aligning and then clamping VeloAngle to the crank arm is, with the saddle or handlebar adapter strapped in place, to move the crank arm back and forth on either side of being in alignment. The point at which the length measurement is greatest is also the point where the tool and crank arm are aligned.


As shown in the home page video, once these fixed adapters are installed the relationship between cranks, saddle and handlebars can be captured in as little as one minute.