I'm totally happy with the tires! I was a little skeptical that I can use at all because I let it never managed with light toy tire circling a Hullahupreifen! This "Hoop" it comes at last, and it's totally fun! Do not think it hurts and what is also important for me: the tire does not smell of harmful substances! Installation was easy. Everything easy. I'm curious as to when I see an effect, but in the training I can only say: The journey is the reward! Power just FUN !!