I have been reading about all the problems with wobble and I just 
remembered something the mechanic in the shop told me when I had the 
front tire changed. He said to always make sure the wheel goes back on 
in exactly  the same postion it came off the hub, including putting the 
lug nuts on the same studs. He told me this would prevent wobbles and 
the front would be balenced better. I went out and popped off the lug 
nut cover and sure enough, the wheel was marked, the lug nuts were 
marked, and the hub was marked to make sure the wheel went on the same 
way it came off.

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The front is a breeze to work on.  Just pretend it's a car that allows you
to work from both sides of the tire.  Don't try to cut corners on removing
the front fenders.  Both need to come off or you can really scuff up your
front wheel on the brake caliper.  My only visit to my GTS-certified Yamaha
mechanic attested to that.

There is a metal bracket between the two front fenders that at least needs
to be loosened for the tire to clear.  Removing this piece would be a good
idea on your first try.  The 120/70 works great, you'll be glad you did it!
 I suspect that the 170/60 rear is probably a little better than the
180/55, but I'd be splitting hairs on that call.

Working on this bike is easier than you'd think, and probably a better idea
than you'd imagine.  You're probably more familiar with the GTS than any
other mechanic in town.

----

If you decide to remove the wheels for any reason be sure that you (A)
replace the front wheel in the exact same position as you removed it,
and (B) reset the rear wheel ABS using a Yamaha coupler reset tool
(alternatively you can reset it by connecting the light blue wire to the
black--all located at the rear sender unit by the wheel, turn ignition
on and off).  These steps are important because they erase the past ABS
faults from the ECU memory.  Technically, you should do this with the
front wheel too, but if you're careful and replace the wheel exactly
(mark on of the lug bolts and the inside of your rim--do not rotate the
hub!) and not have to go through any reset procedures for the front.

This all sounds a little more complicated than it is, but it is
important because you will affect the ABS functioning if you are not
careful.

Eric.

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