We do make a version you can lock into regular cranks, but you have to get off the bike to do it (takes about 30-60 seconds).Billsworld said:Fday, I have them and use them indoors for a specific purpose and mix them with roller work and weights. My only negative observation/suggestion would be to make a version that the pedals lock into the correct forward position. It is hard to get back into correct position when your hip flexors are on fire. Being a fast twitch guy , I simply dont ride enough to fully adapt. FWIW , I can sprint on them but tempo is brutal.