Originally Posted by syzygy9
I am struggling to see how an increase form the stock 0.48 to 0.70 is required. I had my own (2011 990 Adv) forks resprung to 0.56 with a revalve to suit - that's an ~17% increase in spring rate and it seems fine for my 85kg 'naked' + gear + load.
On a recent trip across Australia with lots of fast and slow dirt roads (and some really gnarly sections) I am not aware of ever bottoming the forks but did use all of the suspension travel. Front and rear were set to 'max payload'; with no load this setting feels quite stiff.
I am no suspension guru so happy to defer to the experts, but my understanding was that if you are using all of your travel and not bottoming, you're pretty close to the mark. Of course, if all you are doing is riding on smooth roads than compliance may not be your primary concern, rather things like fork dive under braking, and you can get away with much stiffer and less compliant forks.
Bottoming control is not done via the springs, it is done by the air gap (air spring). This is why setting the oil level correctly on these forks is much more sensitive than smaller size dirtbikes.
.48kg springs are very light, thats what we install in a 4 stroke ktm for riders who weigh in the range of 195 to 210 lbs, and this is on a ike that weighs around 230lbs less not including rider weight etc.