Oh, I dunno there, I was using these exclusively purely because they are so cheap over here in the UK. I actually thought they were OK on carpet gripwise once they'd had a lap or so under them. Now I've found a reliable source of M-Grips though I've stopped using the Ansmanns as I agree, they do take away a little too much top end and as the previous poster said they are super brittle, I've actually had a rim come off the centre whilst cornering WITHOUT hitting anything - the chrome plating was actually thicker than the plastic.