Back during the winter I was looking to buy a fixed gear bike and was'nt sure if I should get steel or aluminum. I read an article by the late Sheldon Brown from his website about frame materials. He said that both aluminum and steel are excellent frame materials and that a lot of the ride quality had to do with tube diameters, lengths and angles. Also tires have a lot to do with ride quality. I went ahead and purchased an IRO Jamie Roy - aluminum frame and fork. I have been commuting to work on this bike since March every day and I love the way it rides. I'm currently running 700 x 23's and am looking to run 700 x 28's or 32's and i'm sure it will ride even smoother.