Hi Tommy, I fitted a new rear shock and a Hagon progressive fork springs earlier this year, the shock is great but I'm not that impressed with the springs so I need to either play with oil levels and/or grades or swap them out for linears and go from there. I've contacted archangel about them but haven't asked about the spring weights. If I get them I'll see how they feel and maybe upgrade with YSS emulators if I think I need them. Like I said to Archangel, I don't object to spending money on the forks if it makes a noticeable improvement to their feel.
Hi Vinnyb,
The trouble with Progressives is that they are a compromise which ever way you look at them, they are what they are, they try to cover rider weight from one end of the weight spectrum to the other, the same spring is for an 8 stone rider up to a 18 stone rider, it just can not work for such differing rider weights.
The original Yamaha spring is said to be 'progressive' the springs that came out of my 2003 FZS 600 were not Progressive, by definition 'progressives' change spring rate progressively across it entire length, the ones taken out of my bike were dual rate with a definite change about 1/3rd way down the spring. See photo of the two springs Linear and the original side by side.
A correction to my earlier post, on reading up my log again the SV650 Ohlin Springs are in fact 10 mm shorter than the original Yamaha springs, but as I fitted the YSS Emulators these effectively add 16 mm to the spring length, so in fact I had to remove 6 mm from the spring top tube spacer.