i have a Marin Rock Springs 2008. it has some rockshox forks that have 140mm travel. a friend is selling his Fox 40's. these have 200m travel and are triple crown, where as mine are single.

Would these fit and /or will it likely void the warranty on my frame and maybe even cause the frame to crack at the head tube?

here is a link to my bike.

http://www.winstanleysbikes.co.uk/images/prod_13838.jpg

thanks Guys

Dan