I have a 7 speed. All aluminum except the #12 cog. (anchor cog??) Very nice and very light and I'm afraid to use it any longer. You need, HAVE TO HAVE, the proper remover for this freewheel. It is kind of like a two prong Suntour remover but the prongs are slanted counter-clockwise (and twice as deep/long) in order to "dig in" while torque is applied to the freewheel. Very cool freewheel just to hold. So light is it hard to imagine.