I find that if the shocks have too much preload on the rear shocks on my R65 Cafe Racer, the front wheel will track in grooves on the road, excessively.
I found this out when cleaning my Konis and leaving them on maximum preload. When I next when out for a ride it drove horribly and my wrists started to ache.
Took me a minute or two to figure it out!
Steve H