RE: Buku pipe
CWC, I just got buku about a week ago, so I can't say for sure. But I would think the cones wouldn't wear out, but over time the spring might lose a little tension. I can't see it being a problem spot. It does come with 4 springs to fine tune the pipe. Ive tested the # 2 and 3 springs. There is a tiny slight difference, but overall, I could run either and not really care too much one way or the other which spring I use. This pipe is insane and well owrth the money.