Hi all,
I own a 1998 Stumpjumper FS and recently upgraded the fork (and everything else that had to go with it!) to a Marzocchi MX Comp with 105mm travel. This is my first real experience with newer forks. Seems like a great fork, but I'm wondering now if I've over-forked my bike (and spent a heap of unnecessary cash in the process) by changing the frame geometry or whatever.

Will a fork this long negatively affect the handling of my bike? And what are the things I should look out for or compensations I might make?

Thanks for any thoughts!

I'm guessing it is fine, but you could give it a little more sag than normal by adjusting the preload.

What did the bike come with originally? 105mm isn't a huge amount of travel even by 1998's standards. You'll be fine.

That's great to hear. It had an old yellow rockshox fork on it, probably 85mm I'm guessing. I think it was a 'quad'.

Also, do suspension forks add a tendency for your front end to slide out on turns?

Thanks again!

I just put a 100mm sus. fork on an old rigid fork frame for a friend. The new head tube angle/seat tube angles are 69 and 72 (as opposed to a more typical xc frame w/ 71 and 73). Sliding the seat forward 1 inch effectively puts the seat tube back to 73 and makes the bike fit her better.
I'm assuming that the slack 69 head tube will increase the chance of washing out in the front. We'll see. Any thoughts on this particular issue?
About your bike... you can measure the angles w/ a plumb bob and some geometry, and see how it compares to the old geometry (or you could measure the fork and calculate the new angles).