There is something "off" with the steering on my 2014 Trek Stache 29'er hardtail since I upgraded my fork. Factory the bike came with a Rock Shox XC 120mm, 32mm Stanchion fork. After upgrading to a Fox Float 120mm travel, 34mm Stanchion fork, the bikes steering seems "squirrly". -Not linear. The feel of the steering is a slight effect like there is some kind of resistance initially followed by a slight over steer. I've checked my tire pressure, and we've pumped them up hard just to prove it isnt a matter of low tire pressure. The best way I can describe it is "Not Linear". What I feel is a narrow bandwidth where for the first few degrees of steering input, the front end resists, then over steers. Could this be a head tube bearing issue? Problem with the headset? Fork? I've invested alot into this bike. Any ideas?
I agree sounds like a headset issue either not sitting square, impropper tightning or just blown bearings or race. I would also double check that the offset of both forks are the same.
If the headset is ok, go check your previous fork offset, from your description it looks like you feel whats called wheel flop, it oversteers at some point through the steering and needs to be counteracted or ekse will flop inside like a coin loosing momentum.aybe you got a 29er boost fork with 51mm rake. It's the only aftermarket option for the 34 but not sure, check your stanctions it should be written somewhere with the rest of the forks specs. Also check your standard forks rake