Tire Fit Gauge

How wide a tire can you fit on a particular bike? It’s a common question, especially when converting a bike from one wheel size to another. The Tire Fit Gauge eliminates the guesswork: One end hooks over an axle placed in the dropouts. The other end has slots for three wheel sizes: 559 mm (26”), 584 mm (650B) and 622 mm (700C). Discs that represent different tire widths fit into the slots: 23, 34, 38, 42, 48 and 54 mm. Slide a disc into the slot for a rim diameter, and rotate the gauge around the axle to check the clearances for this tire size all around the frame.

The gauge is laser-cut from plastic. Remove protective cover before you use it.

Pro Tip: The gauge is designed for the 13 mm dummy axles used in frame jigs. To use it with other axles, increase the diameter with a few layers of tape.