No, actually, a 20" bicycle tube and a 16"moped tube are exactly the same size. I never could figure out why they call Tomos wheels 16", when they measure EXACTLY 20" across. No part of a Tomos rim measures 16". You can even put a 20" bicycle tire on a 16" Tomos rim, and it will fit perfectly, but that I do not recommend, unless it is an emergency, and nothing else is available, then keep your speed down to no more than 15 mph, until you can get a proper moped tire. In fact, if you are going to be anywhere near a place where you can get a real moped tire, those fold up bicycle tires make a good emergency spare, that's easier to carry than real moped tires, just like the donut spares on cars, you just have to realize their limitations on a moped. And for anybody who thinks those puncture resistant bicycle tubes aren't as good as a "real" moped tube, take a "real" moped tube to a bicycle shop and compare them. The bicycle tubes are actually much better. I've used them for years with absolutely no problems, and a lot less flats. I also use 24" bicycle tubes in my Solex, which has 19" rims. Normally, they would be 1" to big, but the Solex tires have a very high sidewall compared to a bicycle tire, and the outside diameter of a Solex tire is the same as a 24" bicycle tire, so they fit.