The top ones I have done are a Nitron R1 Mono-Shock on the ass end.
And with a lot of encouragement from Kebab, and, also reading his posts on the subject, I did the front fork conversion, converting from 'Damper Rod' suspension to 'Cartridge Emulator' (YSS Emulators) suspension and fitting Ohlins Linear Spring matched to my rider weight.
I deviated a little from Kebab's posts when it came to overcoming the damping effects of the Damper Rods, because the rods on the 2002-2003 FXS600 are shorter that the earlier Boxeye.
A very, very worthwhile upgrade. I could have done it for less money by going the second-hand R6 shocker route, but I didn't.
Spend in total start to finish about £650, maybe a tenner more, maybe a tenner less
I know that it is dead money and that I will never recoup the cost, should I ever sell it on, but the bike handles so, so much better, it steers into bends better, holds it's line better without any diving in on undulating surfaces.
I have so much more feel through the bars I feel now have contact with road surfaces, and, the ride comfort is much improved.
Would I do it over again knowing what I do now? YES I certainly would.
It is not a difficult thing to do but it takes time and you need to work methodically and accurately when drilling out the Damper Rods to overcome their effect.
The thing is I guess I am less likely to lose the bike cornering now, but with saying that I am cornering faster, I feel more confident and my chicken strips have diminished 50% in the last 5 rides.
