Bicycle Crank Spindle Tape Measure Holding Tool

Inspired by the Abbey Bike Tools Saddle Height Bullet (part of their Fit Kit), these tools are inserted into the end of an installed bicycle crank and allow for easy and consistent measuring of saddle height.

Improvements from the Abbey version include a couple different spindle sizes and lengths to friction-fit (staying in place on their own) in a range of cranksets, and availability (the stand-alone fit bullets do not seem available for order in the US).

There are four models here which cover all the cranksets that I have access to, and most that I can think of:

• 8mm (8): Fits in most cranks that tighten with an 8mm hex. Tested on SRAM GXP, SRAM DUB, Praxis ALBA, and Race Face Aeffect cranksets. (8.1mm ∅ x 13mm)
• Shimano (S): Fits in most Shimano splined preload caps. Tested on FC-M8100 (XT), FC-RX810 (GRX), and FC-R7000 (105) cranksets. (13mm ∅ x 10mm)
• Race Face Next (N): Longer version of 8, intended for cranks like the Race Face Next series whose bolt is much further in than most other cranksets. This version is too long for other cranksets, like SRAM GXP and DUB and will bottom out leaving the tool sticking out and less stable. (8.1mm ∅ x 20mm)
• Square Taper (☐): Fits in most 8mm square taper crank bolts, which have a much shallower depth than hollow spindle cranks. Likely also works in ISIS and Octalink cranks and others which use a standard crank puller. May need to be held in place by hand because of the shallow bolt head. (8.1mm ∅ x 5mm)

Additionally, a recess in the hook slot allows an optional 3mm x 1.75mm magnet to be pressed into the center, holding the tape measure hook in place for even easier measuring. The model indicator is a shallow (0.001mm) recess that can be colored for easy identification (as shown in the examples), or if left uncolored will not be visible after slicing.

I suggest printing with random seam, as the slight ridge from a normal seam on the spindle insert can hinder easy rotation of the tool while measuring. This prints without support on a Bambu Lab P1S using PLA filament.