Originally Posted by reollc4
I have picked up some 48mm x .48 wp fork springs for the 640 but they are the 510mm long ones for i think exc or sx will these fit my 03 640 adventure.
They'll fit, but you'll really have to cram them in there.
The stock adv spring (for the 48mm WP USD forks) is 43mm x
485mm (edit). mx-tech sells 43mm x 495mm springs (linky)
which I have in mine. It took a bit of a squeeze to get them in, but they work. There are also some spacers in the forks which I will remove soon to get the front end sag right. The 510mm springs may have too much preload to work right.
It is possible to cut the springs down if you find that they are too long- this will increase the spring rate slightly as well.