found this on the old site
"I finally got hold of a thou shock at a reasonable price,now fitted to my 02 600 foxeye , it works a treat, to the point where the rear suspension is forgetable, before I had pogo effect when pushed hard , Now twisty bumpy roads are a much more pleasant experience, Fitting involves swapping the 600 spring onto the thou shock, for this you will need a spring compressor "can be done with big jubilee clips" an angle grinder and a bench grinder is usefull. the spring collet retaining washer on the thou shock needs to be reduced in diameter also plastic spring seat reduced, "bench grinder" also the spring tension adgusting bracket will have to be ground away "angle grinder" on the side away from the gas can ( otherwise it will wear away the coolant overflow tank) I set my shock spring at one click from softest . For my weight 10st this is perfect pre load .Then I moved the said coolant tank to the backside of the mounting on the nearside of the bike "same reason" This is a bit fiddly you may have to devise a retaining clip . no big deal as it is still mouted firmly on the otherside of the bike and there is no weigh/load on the tank . apart from setting the rest of the shocks adjustements to medium that is it. The adjustment on the spring is now fiddly but no more adjustment seems necessary.best mod since home made vario"
another option get in touch with devils yam about an R6 shock mod this would probably be easer