I think they rob power. I had one and it made a bunch of noise. I bought a chain slider from T.M. designs. That thing is bad ass. Life time warranty. You got to take through bolt out and drop the swing arm a bit. Got to take off that piece of crap roller and silver doughnut thing. The chain wears down slider a bit and just sits in it's own grove. I think they make it oversized for that reason. Keeps it from going side to side. Anyway another option for you.