Which claims? The only one I saw that was a bit of a stretch was the FZ1 at 175mph... The FZ1 is a stout bike, but even with a pipe and a tune, the 160's is about all they can do...
The power on today's bikes are insane. The 1198 that I had was putting down 162hp and 92ft/lbs of torque at the wheel on the dyno, in a bike that weighed about the same as an R6... And the bikes today, are a good step up in power from that, many of them pushing 180hp+ at the wheel in stock form...
If not for modern electronics packages, we would be picking a lot more riders out of ditches and trees...
It's why you are seeing 600 class sales plummet. Literbikes are no longer as scary as they used to be. With ABS, Traction and Launch control, variable power modes, etc... You can take that fire breathing monster, and with the flick of a switch transform it into a tame pussycat...
175 on a FZ1? I must have missed that one. I've run that fast and a bit more on a Busa but never my FZ1. I've never wrapped out my FZ1 but I doubt I could get it much over 150.
As a general rule I keep under triple digits.