04 GL1800 rear end wobble....new tire

I just changed my rear tire. I replaced it with the exact same tire that was on it.....Bridgestone Ecopia EP422....195/55/16. I was riding to work

Monday, and one of my co-workers said that my back tire was all over the road in the turns (not big ones either), and I felt like it was flat and I

was going to lose it. This was happening at 60-70mph. I checked the air pressure with a couple of gauges the techs at work had, and mine was off

by 10 lbs. I added 10lbs and brought the tire up to 40psi, which I thought might be too high. I rode home through town at lower speeds and didn't

notice any wobble. When I got out on the 4-lane on the way to my house, I opened it back up to 60-70mph, and the wobble was still there, but

not as bad. Then this morning on the way to work, I was got behind an 18-wheeler running 65, and WOAH!! it really felt loose, REALLY LOOSE!!

I had to back off, and only ran 45-50 the rest of the way to work. I put the bike on the center stand this afternoon before I left work and tried

moving the wheel from side to side...no looseness, I pumped the tire up to it's max recommended pressure of 51psi, and came home. I ran it up

to 80-90 before I felt any wobble, but I really think that 51psi is too much to be running in the tire.

My question is............Is anyone else running the SAME TIRE, and if so, what pressure are you running, and do you have any rear end wobble. (It feels just like the tire is low on air or flat)

When I put the first EP422 on, it felt a little loose when cornering in the mountains, but that passed after a short while, and I didn't notice it

anymore unless I got into the triple digits, and then I think it was just the wind buffeting me around.

If you were running the same tire before and had no issues,proubably a bad tire .look at the tread when tire is spinning if it runs crooked the tire proubably has seperation.

How is this tire balanced?
Sounds like it is way out of balance, and it shows up at speed.

Sounds like the tire you replaced it with has a lot softer sidewall than the last one did. I have about 40k running 205-60-15's in the non run flat variety. They were bad about the wobble you describe. The lower the pressure the worse they were at high speeds. 80 mph was top speed until the wobble started. I have since installed a michilin primacy alpin pa3 and this tire is way awesome. I have to literally watch my speeds as I will climb into triple digits and never realize it.
I found with the soft sidewall tires that the higher or lower the pressure the feeling got better. The problem with the lower pressure settings is that you will over heat the tire.

Running it at the higher pressure will not hurt it but will cause it to wear in the center faster.

See you out there
Smokey

Thanks for the input guys. Smokey, what you said seems to be the most logical reason for the wobble to me. When I had it up on the center stand, a friend, and fellow biker--(not a darksider), said that the sidewalls looked like they were flexing too much when I was shaking it checking for looseness. It was his suggestion that I put the max pressure of 50psi in it. I've got a ride planned this weekend, and will make a decision on what to do after that. Thanks, Randy