I have a Dahon Speed Pro TT with 20 inch wheels. The front wheel only has something like 14 spokes and was able to get the light to stay on just fine stuck between two spokes. Hasn't fallen off yet! The back wheel has a few more spokes so the light is a bit more secure. But again, works on the front wheel too. I think that's because of the deep grooves on the SpokeLites.