Check your front wheel bearings, also stand the bike straight up, and check wheel alignment.

 

I wear the left more than the right on every street motorcycle I have owned. Thinking about it when I ride I have no idea why. Apparently its just something I do more of left turns, harder left turns, than right.

Until recently the left front would wear out just barely ahead of the center front. Then with Roadsmart III tires I wore the left rear a good bit faster than the center rear. Twice. Two tires. No more RS3's for me, Bridgestone T30 Evo GT currently mounted front and rear and loving them.

 

Most roads are crowned in the center, so in theory you'll be riding on the left portion of your tires more than the right portion. Not sure if this is true in practice but I suppose it does make some sense.

I think the GT version of the T30 EVO is too stiff for a light bike like an F800ST. When they wear out, consider trying a pair of the non-GT EVO's (the T31 now) and see if you can tell any difference.

 

Like the earlier poster, I would guess alignment. I don't know if there's a better way to check other than a string line. I've never had one side wear, but I always get pretty bad cupping on the front tire.

 

How many miles on the tire, Norm? What roads do you ride most often?
Cross country with a prevailing wind pushing you one way or another?
You could loosen up all the nuts and bolts and get the front to relax again. I needed to do that after I high sided once. The front was tweaked all to hell. I could hear it creak back to normal as I loosened up everything.

 

Road camber?

 

I asked the manager about alignment and he told me that you do not have to worry about the alignment on a F800 due to the belt drive/swing arm assembly.
Most of my mileage has been commuting approximately 100 miles 4 days a week on the freeway HOV lane. I may be more "comfortable" turning in one direction than another but I don't think that would account for that kind of discrepancy.
Nota, I have put on about 8,000 miles before I needed to replace the front. The rear wore out much faster on a pair of Michelin Pilot 4s. They were my second pair. I have now replaced them with the Michelin 5s. I think it might be the little fender bender I had years ago, but I think the wear pattern should have shown up sooner.
I am still puzzled.

 

Many of our roads have 2 dips in the them from the heavy traffic. I watch other riders, and most ride to one side or the other of the dips. A buddy I ride with complained of her tires wearing more on the right side. So instead of leading like I usually do, I followed her oneday, she rides most often in the right side of the dip to the right of the lane she is in, thus wearing her tires right side more. It very well could be the roads you ride on, and how you ride those roads.

 

Those 'dips' are the wear from truck traffic. I've noticed them on I-40 and other interstate highways. We don't have much of that in So Cal where Norm lives.
He did go out of state on an adventure, maybe he had too much fun in the hinterlands. Or that's a really crappy expensive tire?

 

Ok I have noticed that the chicken strips on the new tire are worn only on the right half of the tire, so something is still going on.
I think the front end has been tweaked a bit from a little unintentional off road excursion.
So I think I need to somehow align the triple tree?

 

Maybe you don't like left hand corners?
Try loosening up the fasteners, axle, fender, fork brace etc as you work your way up.
Don't loosen the triple tree too much or the forks will settle in the head. That could get messy.
On the center stand with a jack under the engine so the wheel is off the ground.

 

Ok, the further adventures of unusual front tire wear................
OApparently, it is road camber.
He also asked me what tire brand and if I keep my air pressure up and when was the last time I had the fork oil changed.
So, it seems it is freeway road camber as well as these factors.