Hi!
I'm building a fixed gear mtb that will be probably used 80% of the time on the road and 20% of the time on the trail (Nothing fancy, just off-road)
My only option for a decent fork for this bike is a NOS 100mm RockShox Judy LT.
Should I even consider it (The old suspension fork was 80mm if I'm not mistaken) ot use a simple (no bling) rigid fork ?

if youre using it 80% of the time on the road, and when offroad, just simple offroad rinding, why not build up a cross-bike? would be way better i would think.

Do you want suspension or not? It's really that simple. Will your 20% of off-road riding benefit from a sus fork? If so, go for it ... if not, go rigid and simple.

... Brad

go with a rigid fork they are pretty inexpensive...and if you are riding on the road 80% of the time you will appreciate the rigid front end. if you end up wanting some more cushion then run some big fat slicks like the bontrager big hanks or semi slicks like the kenda krad or maxxis holy roller. I run the kenda k-rads(1.95") on my around town SS MTB and I really like them so far.