-
I thought as much but my theory was completely un scientific or taking actual angles into account. My theory was that by adding a taller fork, it would raise the front end but make the wheel base slightly longer and slacken the angles like modern hardtails. I have no clue whether this is true though.
ricky2slicky-
My theory was that by adding a taller fork, it would raise the front end but make the wheel base slightly longer and slacken the angles like modern hardtails.
Yeah, but no.
It will slacken your head angle and lengthen the wheel base, but it'll also lift your bb, slacken your seat angle and reduce your standover.
I put a longer fork and a 29er wheel on the front of a not so old Genesis IO and it really wasn't as much fun as I imagined it'd be.
I had pretty much zero bb drop which made handling pretty weird and the 3rd or 4th time I cracked my nuts on the toptube I gave in and built something else. A 90s bike will have even worse standover issues as the frames don't tend to be that compact.
M_V
It will change geometry but I don't think you will feel much difference. I ran Rock Shox Reba Race on a bike that came with classic steel forks and it performed more than decent.