Pigeon Roost said:
The problem may be with the tires themselves (seems VERY odd to me that there could be so many "bad" tires out there for the GL1800), or the installation of those tires on the rims. The tire realted insall variables are balance and the quality of the bead seating job at either or both front and rear. The quality of the wheel install job back onto the bike at either front or rear can be considered too.
I can tell you for a fact, that in my 25 years in the MC biz, no other model of bike gets "bad" tires, except for the Goldwing. I find that odd.
Dunlop, Metzler, Pirelli, Michelin, Avon, Bridgestone, Maxxis, etc, etc, etc, all make tires that go onto every model, size, and type of bike and work great, but when any one of those companys puts a tire on a Goldwing, somehow, about 50% of them are bad. :?
As for how they are mounted, that's basically 1% from impossible to screw up. You fill the tire with air, and it goes "SNAP!!! SNAP!!!" when each bead seats. It is loud enough to scare people who aren't expecting it. That's it. You aren't going to do a better job by repeating that several times.
I have personally mounted thousands of tires on bikes, and watched tens of thousands get mounted on racing wheels.
I have been in tire tents at World Superbike, AMA, WERA etc. Two snaps is all that is required to know the tire is mounted properly.
For balancing, again, no dramatic process is required. If you question the bike shop's computer wheel balancer, have the tech stick the axle through the wheel and put the wheel on a pair $9 jack stands. If the wheel is in balance, it won't move. THAT'S IT.
Go to Daytona and watch how they balance tires for bikes that have 2X the HP, weigh 1/3, and go 2X the top speed of a GL18. They have a stand that costs $200, some axles, and some wheel weights. There are no computer wheel balancers at a race track.
Do you think a poorly balanced tire is more critical at 40mph or 190mph?
No one ever goes to the trouble of dismounting and remounting the tires to get it exactly positioned so that you use the least amount of wheel weights. That isn't what causes bikes to wobble.
If you are going to these lengths to make your GL not wobble, you are grasping at straws.
Different tires do have different characteristics. This guy's steering head could very likely need adjustment, and the stock tires mask it. A different brand may just let the symptom exhibit itself.
We have found at least 7 factors that make a GL have the decel wobble. One of them can cause it, but typically, it's a stack up of several factors.