My GP4000's and Attack/Force combo on my Easton Circuits are a test in patience and perseverance. The first time is the absolute worst... Took 10 minutes to just put Attack onto my front. Transferred the front GP4000 to the rear, still 2-3 minutes. I just pray I don't get a fast flat whenever I ride (Only had two in 2000mi! Both slow leaks I found when I got home. Knock on wood)