From day one, I noticed the front wheel of my recumbent was always tilted a little to the left, and the boom a little to the right, indicating the bike was going sideway. A friend also told me the front wheel seemed to roll about a inch to the right of the rear wheel, which I confirmed by following him on my bike. When I tried to eyeball the bike carefully (without me on it of course), I couldn't see much of anything. I also brought the bike back to the manufacturer to have the frame checked out, and he couldn't see much either. So eventually, I filed the slight crab-like motion under the oh-well category and I've ridden the bike like that ever since.
Today however, I decided to change the preload on the POS Rockshox Judy TT fork that's currently on the bike, and while I was goofing with the (single) adjustment knob, I was pushing on the bike hard to test the fork's hardness, and that's when I noticed the wheel bending ever-so-slightly sideway as I pushed. It occured to me that, with a spring only in the left leg of the fork and the probably not-so-tight tolerances the fork was built with, it makes sense that the fork deflects to the right when it's under load, which would explain why I see my bike running sideway when I'm on it, but neither I or the manufacturer see a problem when I'm not.
So my question is : do you guys know if this is a common problem with cheap mono-spring forks ? I'm more than happy to get another one, especially since this one is generally sloppy and crummy, but I'd like to know if I should get another fork that has a spring in each leg. If I change the fork, I won't get anything fancy, it's just to soak up bumps on the road, but do you think I should avoid forks with only one spring?