I took my 21r to a friends place because he just had a 2.5 km straight driveway built on his farm. I warmed the bike up and took it for a thrash. It pulled really well until I got to 180 in 5th redline and went to change into 6th and the back wheel locked up and left a 90 meter black line down his new driveway. When I finally stop (without coming off) I tried to kick her over and there was no movement. I gave it a bit more and it freed up. I got it started again just to try find the problem. The top cylinder seems alright and the bottom has a very erratic exhaust gas release.

Just wondering if this has happened to anyone before and how much damage have I possible done inside.

Cheers