I've got a Ducati 900SS, and I was clocked at 125MPH on the front straight a Heartland Park raceway in Topeka KS. That was as fast as I wanted to go, because it's the 1/4 mile track used for drag racing, and then there was a sharp right, then an immediate sharp left turn at the end! You'll see it in this photo at the left, about 2/3 of the way down the straight.
The worst part of the track (the first time I rode it) can be seen on the right side... Notice that it seems to be straight, then there's a litle "chicane" (a jog, to help keep the speed down), then another short straight... What you can't see in this photo is that both strights are going slightly uphill, while the chicane is flat and level. That means you can't see the chicane until your're practicly on top of it... My first time there, I managed to do a bit of "dirt tracking," going straight, missing the chicane altogether! It was a serious "pucker factor" moment!
the last time I was there, Heartland Park didn't seem like a terribly safe track for motorcycles... The track surface was pretty bad (there were different surfaces at some of the points where the bike was leaned over, and traction would change), and there was limited "run-off" space, especially at the top of the photo, where the road course merges back with the 1/4 mile drag course, where if you ran wide, you would wind up hitting concrete barriers! It's been a while since any major races or riding schools have run there because of those conditions.
Mark