My guess is that they go over the originals aswell.
Managed to get one on last night by heating it and cutting a little expansion slot, but it is on so tight, god knows how I am going to adjust it.
Mate is bringing home something that they use to widen pipes, like a wedge that you hammer into the pipe. I will give that a go too.
I had the same probs with my Gixxer..
But they sound so nice and I got them at a bargain price, so I had to buy them again..
Mark