Progressive springs

A reason to have the tighter coils at the top is to reduce unsprung weight ie. the parts which go up and down. Multi rate springs should have a longer free length compared to standard because they include a section of 'soft' coils, the ones closer together, which are the first to compress. If not the static sag will be greater than with a standard spring hence the required preload spacers. Having tried multi rate and gone back to standard I think you're better off with a single rate spring as long as the rate (lb/in) is matched to you and the bike. Hope you're happy with the springs Chris.

I use progressive springs bought from RGM in my 1960 ES2.One thing I found was that they seemed to make little difference until I changed toa lighter fork oil (from SAE 20 toSAE 15 I think - the labels come off the bottle dammit!) and they have resulted in a far better ride. I would think that most 50 year old springs would have lost some of their 'spring' by now which could explain the ride height conundrum (or see below). Several different fork springs were used by Norton and were usually colour coded with the first coil or so painted. So far I've come across Yellow (sidecar), red, green and orange. The set that were in my 58 Dommi were very light and, as the bike was only 6 years old when my Father got it, I would think they're the original ones (i think they were the red ones).)So light in fact that they would bottom out when ridden hard so I swapped them for a set from a 650SS. Looking todayat the parts book it gives an F11M number for the 50s Dommi's springs( i.e.1951 Manx Norton No.) so I guess its hardly surprising that I found them well suited to my Manx style Inter. The Dommi is being rebuilt at the mo' and it toomay well end up with progressive springs.

Hope this helps in some way.

Ian.