Suspension Spring Change (purchase help)

[tmotten]

G'day,

I've recently done a big trip with way to much luggage and did notice that the springs (which I think are stock standard) are simply not up to the task. Bottoming out and heavy sag at heavy braking and that. So I'm thinking of upgrading the entire suspension to suit the added weight for which the originals are not designed.
I'm going to get the rear done by a specialist, but thought I could just get some heavier front springs to suit my riding weight with luggage. I could then muck about with the pre-load to suit.

The only thing is that I don't really understand how rating them works. I've emailed several manufacturers, and never got a usefull reply. I understand that springs get rated by kg/mm. But does this translate that if you ride with a weight of 100 (rider + riding gear) + maybe 80 for luggage (incl. racks and protection), and the spring travel is 255mm for a 3aj (found on the web somewhere) you end up with 180/255= 0.7 springs????

And then there is the choice between progressive and normal. All I want is to have reasonable handling on shitty roads and dirt tracks and that.

Cheers, Taco