Tried another size up and the only difference was that the back was longer. I didnt bother with the ruler. Great purchase, awesome price. One caution, if your shoes have no "heels" they may slide unless you push them up or glue medium grit sand paper to the bars. Arrived a little late but not to bad. That left the 8 long hex socket screws to assemble the pieces together. No las he vuelto a usar. Started bending after two weeks. These work great for electric scooters with open spoke wheels. Dont let the removable cat ears or cutesy logo fool you: this headset is TOP TIER.