Tire Fit GaugeJan Heine
How wide a tire can I fit on my bike? It’s a common question, and yet it’s difficult to figure out, especially when you plan to change wheel sizes.
Hahn Rossman has developed a simple tire fit gauge that allows checking tire clearances on your bike. Put the disc for the tire width in the slot for the wheel size. Place the gauge on a dummy axle (any old hub axle will work). Rotate the gauge around the axle to check clearances between the chainstays, at the back of the seat tube and between the seatstays.
It’s such a simple tool that you wonder why nobody else has made one before. Above, you can see that if your frame has clearance for 700C x 23 mm tires…
… you may also be able to fit 650B x 38 mm tires…
… but you need a lot of extra clearance to fit 26″ x 54 mm tires.
The outer diameter of all wheels is the same, but it’s the clearance to the chainstays that is often too tight. The gauge makes it easy to visualize where the widest portion of the tire will be. It eliminates the guesswork that can make conversions to different tire sizes a hit-or-miss.
The Tire Fit Gauge is laser-cut from plexiglass. It’s in stock now. Click here for more information.