Your front tire is bad. Depending on the tire, when they wear, they'll cup on
alternating sides. At lower speeds, this will cause an oscillation - death
wobble. Bottom line, buy a new front tire. If it doesn't help - you still have
a spare. When you do replace it, make sure the tire is at or slightly above
the recommended max pressure - it'll last longer with out cupping.
Sven the Viking
Roberto Alonso wrote:
> Hi all,
>
> Some quick answers to your remarks about my furious head shaking (my bike's,
> that is):
>
> In no particular order:
>
> George:
>
> I stated in my post that I wanted to keep the Wingrack 'cause I already have
> the three cases for it, some inherited from my late brother. Krausers are
> not an option, and a trailer I won't be caught dead with. They're illegal in
> Spain, also. I am aware that worn tires can do this (and mine are), but this
> is an overnight thing, it was installing the rack and wham, there goes.
> Nothing else has been done to the bike in the last 5000 km.
>
> Mike:
>
> Man, you sure misread one of my emails, probably due to my broken English. I
> have NOT modified the frame for Krausers, never had them and doubt ever
> will. I do have the bar connecting the two side racks from behind, and the
> latest Wingrack. It is featured at www.givi.it/sub_index/english/wing.html
> with the reference E141. Everything looks well installed.
>
> Jon:
>
> Tires are halfway gone, but so were they when I left the bike at the shop
> and not a problem. I've inspected the rim for damage, it all looks ok.
> Again, NOTHING else was done to the bike in the last month.
>
> Nicholas:
>
> As I said, I refuse to believe it's down to aerodynamics, since it will
> happen at as low a speed as 30 mph, and also without cases. I do not often
> ride with my hands off the grips, but like to be able to, for several
> reasons:
>
> -to close both latches on my BMW helmet chin bar at once,
> -to pull up a jacket zipper more easily (not easily done when crouching on
> the bars),
> -to do a quick shoulder stretch,
> -because the bike should ride nice and straight with your hands off, if it
> doesn't, something's not right.
>
> I always do this at less than 40 mph, and never had a problem, until I put a
> case on the rack of my XJ600, or a wingrack on my GTS.
>
> RSRBOB:
>
> As always, your answer is the most useful of them all. Man, you're a living
> encyclopedia. As I said, no prior work on the bike for some 5000 km (rear
> tire replaced then). Nothing looks out of check, rim seems fine and disc has
> no sign of warping. Bike is just fine unless I get my hands off the bars.
> Will have my new mechanics look at the steering (I'm not mechanically
> inclined enough for that). They are knowledgeable on Yamahas, but have no
> extended experience with the GTS (hey, at least they will say so and accept
> customer directions). Any input about what exactly should be done and
> checked down there? I already had them contact Givi about the matter, but
> it's too soon for an answer.
>
> Thanks to all for your input. I was wondering if some rubber washers would
> help kill vibration and help somewhat. What do you think?
>
> Roberto.