I recently changed front and rear tires on my 04 R1150RT; went from the Metzeler Z6's, to Mich. Pilot Road 2's. I replaced the rear tire 1st, and then the front tire about 1,000 miles later.

But here is the thing....

Within about 300-400 miles after changing the rear tire, I started to feel a very odd sensation. When I lean into a low speed (10-15 mph) left hand turn the bike almost feels like I have a flat tire; if this is happening while making the same sort of right hand turn, there is very, very little, if any, similar feeling. For a while, I thought it might have something to do with the old front tire as it was pretty worn on the left side (which seem to be typical...to a degree due to weight imbalance); but after I changed it out for a brand new Pilot Road 2, there was no difference. Also, if I am leaning into a left hander at a higher rate of speed, it feels normal.

I have placed the bike on the center stand (several times), and I have tried to see if there was any movement when holding the tire in the 6 and 12 position; and again at the 3 and 9 position. Nothing, nada, no movement at all! I also tried to see if I could wobble the rear wheel from side-to-side (left to right), and again no movement at all.

Both tires appears to be correctly seated, and mounted in the proper rotational direction, and there does not seem to be any unsual wear (approximately 1,500 miles on the rear tire, and 250-300 miles on the front).

I can rotate the hub (without the wheel attached), and there is a little bit resistance (bearing load resistance I assume), which I would think is normal, but there is no feeling of roughness or unusual grinding sounds. Seems normal; I think.

Lastly, I recently did a transmission and final drive change, and again there was nothing unusual, clean and clear. What I forgot to mention was, the bike has 40,700 miles on her as of today.

So, I am seeking the advice from the collective; any ideas of what this might be, and way only on the left turn/lean side??