Flats suck. Good thing we have replacement tubes.

If you don't see what you're looking for, please let us know - it's always possible for us to make a special order!

Quick FAQ on tube sizes. Behind the scenes we use the ISO/ETRTO system, and wish the rest of the world did too—its the most standardized, consistent measurement system for tubes and tires, compared to the British and French system that are often more common place. French 650a can be easily confused with 650b, 29er is the same as 700c just plus size, but 700b is dutch bikes. 26" can mean many things, most commonly people are referring to mountain bikes but know that 26x1.75" and 26 x 1-3/4" are not the same size. I know— puzzling... anyways that's why if you give us a call, chances are we'll ask for an ETRTO size off the sidewall.

ETRTO (European Tyre and Rim Technical Organization), now ISO, is a simple metric measurement of rim diameter at the bead seat, and width of inflated tire.

Test time: Dutch bikes typically use one of the following tires: 40-635 or 40-622. What's the difference? If you said rim diameter you would be correct. 635mm is the older 28x1-1/2" designation. 622mm is 700c, the same wheel on most contemporary bikes, whether road, mountain, or hybrid. 40mm is the only tire width available for 635mm wheels, whereas the myriad of options available in 622mm, with the limiting factor being what the frame can take in width. Some of us have 47mm wide 622 tires on our dutch bikes but they don't always fit.

There is considerable leeway on tube sizes. Old 10-speeds used 27x1-1/4" wheels (32-630) have no issue using 622mm tubes. Schwalbe 26" tubes often are designated for 559, 584 and 590mm wheels.

You can read more about tire and tube sizes an history from the late and great Sheldon Brown.