They aren't "solid" like tricycle tires, they are more like run flat, neoprene with air core. Some bicycle racers in the Tour de France run them so they do have some suspension. May want to do some research before ya poo-poo them. The owner of the local bike shop uses them on his commuter bike and says they softer riding than his normal "high pressure 55-65psi 27" road tires. At under $40 per tire I may try a pair. He's checking for a set with whitewall and if they have a bit wider tire. (2.125 vs 1.9)