I took off the original tyre last week, it was the original one that Yamaha put on (can't remember, Dunlop??) it had been on a full two years and was a complete and total B*&^%RD to get off.

I used plenty of lube (window cleaner and soapy water mixed) and levered it down using the end of the tyre irons that are more angled, the end you don't use to get the tyre on.

The TKC80 went on a piece of pi$$, it was warm as I left it sitting in the sun, that may have helped....