Fat Cat Expansion Pipe

A buddy's kid got that 'un for his ride, it was a direct bolt-on w/o any modification needed. The flange's mount holes oversized a bit we could turn it slightly to clear the pedals on his mountain bike - while it was a cartage style crankset, the pedals were no wider apart than normal. I would recommend some sort of secondary support, I'd worry about the exhaust studs elsewise.

As for power gain? According to the kid it's "awesome" but who knows what that means lol, I noticed it was a bit faster and ran a bit smoother when we took our bikes out for a spin...

It's also freakin' LOUD lol, but he loves that too

26 inch has one on his bike & he's pretty fast! (& pretty loud... )

I have ran a few of these with excellent results and the difference between this and the stock pipe is substantial. As for noise, well I control that with my right hand. It is easy to come off the throttle and quiet things down as I motor by people. I do improve them by cutting off the stock flange and using my own ported flange. I also tuck it up and back towards the bottom bracket when I do the flange swap.