Odd high speed shimmy

[Moonshot_1]

Got a 99 I/S about month and a half ago. Currently on bike trip From Iowa to Yellowstone to Colorado back to Iowa. Right now in Laramie WY on the back end leg of the trip.
All during this trip I have had a shimmy that seems to start at about 70 mph.

My attempt to describe this.

Say "one thousand one, stop, one thousand one, stop, one thousand one, stop, etc"

On the "one thousand one" I get a shimmy that last as long as you can say that.
On the "stop" it stops completely for the time it takes to say "stop"
And it continues at that pace no matter how fast I go over 70. That pulse is like that at 70, 80, or greater.
It does increase slightly in intensity but not the pace.
The shimmy shakes the faring (kinda jiggles on the "one thousand one" beat")

Doesn't matter what the road is like. It is harder to detect on rougher roads as the pulse can blend in with the bumps but I can still feel it there.

It is more pronounced on smooth roads. But I suspect it just makes it more noticeable and not that it makes it worse.

At no time does it make it difficult to handle or control. Just can get annoying on long stretches at interstate speeds.

Under 70 it doesn't seem to do it at all.

But it is a Valkyrie so under 70 is rarely an option.

Thoughts?

[The emperor has no clothes]

My guess would be an out of balance wheel.

[PAVALKER]

Do your tires have wheel weights, Ride On, or Beads?  If only weights, try to add Ride On. 

The fairing is fork mounted and affected by wind.   Might want to check shock bushing as well.

[R J]

I'd say it is a wheel bearing starting to go South on ya.

Jack the front end up, grab the bottom of the wheel and see how much back & forth movement you have.     If close to none, try the rear wheel.

Let us know what ya find out.

[sandy]

Front tires should have 40 psi so check that. Then check the date code on the tire. It's a crude looking stamp on one side. The 4 digits indicate the week of the year and the year of manufacture. A 2010 is the 20th week of 2010. If the tire is old, it may be beginning to delaminate. You didn't say the miles on the bike. If they're high, it could be head bearings.

[Moonshot_1]

Mileage on bike is just over 50k.
Tires are new as of 47k or thereabouts.
Not sure on actual age of tire.
Both tires are Dunlops.

What is confounding me is that the pulsing seems to be independent of rpms, mph, or any other constant.

[R J]

I do believe you answered the question in your last post.

D U N L O P S.

In 242K on MGM I had 3 sets of Dunflops.  Each set had a wobble, shimmy or just a plain old flop.

1st set was all I could get on my trip up to Alaska after I ran over some sharp rocks.   They cut my tires I was running up like sliced bread.

Pulled the Flops off when I hit the lower 48 in Washington state and the shimmy went away on that set.

Don't recall what the situation was on the other 2 sets as to why I happened to have them put on.

I know when I replaced them, the problem went away.

[N8171S]

check your steering stem bearings.  One of my valks did that at high speeds.  New bearings cured the problem.

[RonW]

Is the manual correct in that the top steering stem bearing is a ball bearing? Lower bearing tapered.

[Firefighter]

Both tapered.

[RonW]

Photo below is from the manual, *arrow* points to the steering stem's upper bearing. I did check the Oem websites and the same top bearing is indeed a tapered bearing. I was just browsing through the manual yesterday. And it caught my eye.