I have the Manitou SX-Ti and would like to upgrade it. If I remember correctly, it has 85mm of travel. What would be the maximum travel fork I should be looking at? Would 100mm be pushing it? My LBS warned me that if I went with a fork with too much travel, it would void the warranty on my frame. I also just want to add that my riding style is primarily XC and that I'm around 290lbs... Your suggestions would be most welcomed. Thank you in advance...

Wil