too little travel!

trail jacker
trail jacker Posts: 844
edited December 2007 in MTB workshop & tech
hi all.
i have been having problems with my rockshox tora 302 100mm forks.
i never get more than 60mm of travel with them, regardless of how much rebound dampening i use. the preload dial wont turn as it is set in its position, but i have been told this is normal (?).
i weigh about 9.5 stone, and was wondering if i could change the spring in them to a softer one...?
cheers.