| Cheers for that guys. Im not gonna fit it myself but reading the fitting instructions of the Jonspeed one worry me a little. Does the 'putting it in the oven' trick actually work or is that a bodge thing and would you recommend to stay away from them?
The fitting instructions on their auction are:
"Simply warm in the oven until to hot to touch. Then pick up with an oven glove an slide on the shaft. Cool with water. Not only shrunk like the factory ones these also come fitted with a grub screw to secure to the shaft." | 
