I have developed a riding problem in the last several months that I refer to as the “yips”. After over a decade of riding my 36 inch wheel I am suddenly having problems turning left and feeling like I am cockeyed even when riding in a straight line. As I approach the turn I feel like the uni is leaning left and my left foot starts to fell “light”. As the pedal hits the downstroke I feel like my left foot isn’t keeping good contact and my leg feels too short. To try and make the turn and even out I start pedaling faster, reaching forward and getting more and more cockeyed in the saddle until I nearly wreck and barely make the turn at the last second. The problem seems to be exacerbated by downslopes (even gradual ones). When I turn and start riding upslope I am able to straighten up and feel more normal and in better control - otherwise I feel like I am constantly leaning and off-kilter. This is a much different feeling than the type of day where you just feel a little crooked in the saddle. I am riding the Niterider Lite and this is the first time I have tried this tire. The tire has been on my wheel for about 18 months and it has plenty of tread left. I am suspicious that the tire is wearing lopsided and throwing off the handling. It’s not apparent to my eye when sighting the profile of the tire but it may be too subtle to see. Has anyone experienced something similar to this? I find it odd that nothing else has changed and I ride the same circuit on a daily basis.
I would check that everything is not loose: pedals, cranks, seat post, saddle, and spoke tension. That would confirm it is the tire if everything is still snug and tight as expected. I had something similar when one side of my saddle’s bolts loosened and it was leaning to the side slightly.
Make sure that the saddle/handlebar(?) is inline with the wheel.
make sure the seat post isn’t bent to side.
If all the parts seem to be in alignment you can try flipping the tire. But 36" tires can be very difficult to remove and put back on, you could also just turn the wheel around and swap the crank arms.
Thanks for the suggestions - I’ll check tightness and alignment on everything but I pretty much do that with a grab and try to wiggle test before every ride, I did think about flipping the tire but I figured that would just make me feel cockeyed the other direction. That flipping is easy by the way - with the Niterider Lite I don’t even need tire tools. I guess that would be a good experiment because if it does shift the cockeyed feeling to the opposite side it would confirm the tire is wearing weird. Since it is my first experience wearing down this tire I just wondered if anyone has had a similar experience. Before I tried the Niterider Lite I was riding the T-Monster from Vee Rubber and never had anything like this happen. I got my Coker out and rode it (it has the T-Monster on it) and the feeling is not there.
If your tire has uneven wear to where it causes you those riding difficulties, you should be able to see it pretty easily. So the next thing to check might be rider position. I have found that sometimes I get into an un-centered riding position sometimes, where one sit bone is lower than the other and it tends to make me want to drift to the right, which also comes with more effort to turn to the left. This is more noticeable with curves rather than corners, like curves on the bike path. Hard left turns seem relatively normal. So check your body position while riding and see how centered the “main center of rolling mass” is. 
Funny you should say that John. I have been riding the same seat for a long time and I can pretty much tell as soon as I mount and take off if I have “good seat and good feet”. I have also found that foot position is critical. I’ve been riding for over a decade and I ride an hour a day nearly every day. I have been racking my brain the last couple months trying to figure out root cause - analyzing and sometimes over-analyzing everything I do (or don’t do). I’m determined to solve the mystery. It used to be I would just get on and ride and my only concern was how long could I ride before the seat fatigue got to me. Oddly that has not been a concern for quite a while now (first time in many years). Thanks for listening and for your suggestions.
If you’ve checked all the possibilities on the unicycle then maybe it’s your body.
Do you ride with one dominant hand?
If so, maybe it’s time to bring the non-dominant muscles that aren’t being used up to par.
Somebody just said it recently… when you ride one handed (same hand) all the time your body has a high probability of being slightly twisted. I agree with that.
Maybe this is your body dealing with that imbalance?
This is just what works for me.
Many of my friends think I am twisted.
I am right-side dominant but I still feel crooked even with both hands out for balance - although I ride with my left hand on the seat handle much of the time. Holding the seat actually helps with the yips. For a while I was trying to be extra aware about keeping my left foot engaged with the pedal and consciously pressing and making sure I was pedaling with the left leg as much or more than the right. I found it was more about foot position than anything else. I ride with my left foot more or less centered and 1/2 an inch or so out from the crank and my right foot is slightly back of center and closer to the crank. This is the position that feels right and is probably explained by your idea of it being the body. No one is symmetrical and we all have to find our own sweet spot. I still suspect it is the tire - especially after having a friend ride the wheel and he was having “crooked” issues. I watched him ride (form behind on my other wheel) and he could not seem to get rid of the tilt. He said it was not fun. I have some tires on order. I’ll update when I have a chance to test it out on a new tire.