The combination of carbon(black) shoes and aluminum shoes has been done by racers for a long time and is not meant to last a long time I run four aluminum shoes with good performance and great life span. I'll save the mixed set of shoes for a big race amain when I need the extra smoothness to pull off a win. That is my only complaint. The tires are great on looser dirt and good on hard packed dirt. They are designed to have the small step pin cut off by the owner if you run on hard pack. I saved mine and I keep a set of proline crime fighters in M2 and M3 compond, a set of Panther Komodo dragon soft compounds and proline inside jobs m3 compound. Plenty of other brand work well. I stocked up on front steering uprights and knuckles, a set of suspension arms, clutch shoes and springs