We don't do 30 on the flat very often, but we can pull at 24 when we're in good shape. That's down on our aero bars. We can use every watt we can get. Our oversized PRO4 tires don't look so stupid on 23mm rims. I think just replacing the front with a Kinlin and CxRays made a little difference on the flat. The bike seem to run just a little free-er. I'll do the rear when I wear that rim out, not too long if it keeps raining.