High speed figure 8

[Mildew]

This is pretty much a non valk question but it could be.  A friend of mine has a Kawasaki Vaquero. It has the  fairingand the whole nine yards. Anyhow he encountered a wobble a few weeks ago.  I Ooo pretty much convinced him of a car tire. The last thing I want is a guilty conscience of a crash from a car tire. I rode with him to key West, deals gap and a lot of places in between. Anyhow, he encountered a big time wobble which he thought he thought he was going down. It was a figure 8 style wobble that took the whole lane from the white line to the zipper. He said he hit the rear brakes hard and that was the only way it stopped him. I was just curious if anyone else experienced something like this or of there's a prevention . I told him somebody from this website might help. He said he was running about 80 then leaned on the tank to stretch, gave it some gas then the big time wobble followed.  He's been trying to get it to do it again, Just to have a piece of mind but no prevail

[Fritz The Cat]

No idea but after surviving a major wobble at 80mph, I hope he knelt down and prayed after he came to a stop cause he was one lucky dude.

[Challenger]

What is he running for pressure in the CT? My Good Year TT on the STD would get a high speed wobble above 90 mph if I run it below 35 psi. I figure it was side wall flex letting it walk back & forth. Two up I never experienced it, but riding solo it would. solid as a rock at 36 psi and above. it is now on my I/S for long distance travel and never have a problem even at 32 psi. 

[Mildew]

I think he runs it at 37psi. I know he's had it at 100 mph many times. He said he runs 80 mph all the time on his way to work. He said the wobble took place after he was leaning on the tank then gave it gas. I thought it may have had something to do with the aerodynamics from the fairing. 

[steve 3054]

I have picked up a wobble a couple of times.  Once I attributed it to a aerodynamic issue on the front of the bike and the second due to bad front tire...either way  there are two ways to get out of a high speed wobble, 1. speed up. 2. hit the brakes hard.  Step 3. prayer because if it turns into a tank slapper it will end badly...

[csj]

My 98 Valkyrie has a real bad wobble at about 90mph (got a car tire). I've sorta learned to stay a little slower.

The cause of the wobble is my shock bushings are toast. Replace those rubber bushings with new ones, the wobble completely disappears, until they deform and get squashed again.

There is NO wobble with a MT. Only with a CT.

One would think that the Vaquero also has shock bushings,
ask him to take a look.

[WamegoRob]

The day I went to CT, as soon as I hit the interstate and got to about 75 the rear end started sliding back and forth a bit.  I slowed and it went away.  Sped up and back a few times to verify the symptoms and it was consistent.

Staying slow not being a valid option (the speed limit's 75mph out there) I looked into what it might be... turns out a combination of the tire following the grooves in the road way more noticibly than a MT and that I must be a bit heavy for 36psi in a CT.

I bumped it to 43psi and it got solid.  I can still notice the groove-following but I'm used to it now.

The only remaining problem is convincing a friend that even a MT would have gone flat when the valve stem failed and again when I ran over a big chunk of metal 

[R J]

I had a wobble on my old Yamaha one time in Colorado.

I happened upon a straight road and I'd let her loose, had just gone past a $$$ whne it hit.

The fairing I had just installed started doing some wiggling around and I got the shakes from it.

Pulled over, tightened some of the mounting bolts again and it went away for about 2 or 3 months.     That time I took the Vetter fairing off and sold it.

Check you shock mountings, top and bottom.

If ya have a fairing on it, check to make sure all fittings are TIGHT.

Had a trailer cause it once also.......

[dreamchaser]

Back in 1966 I had a BSA 650 Rocket that got into a lock to lock (steering lock) wobble at 60+.  I just pulled in the clutch and it stopped.  I told the dealer about it (back then you could trust most dealers, because the cared about reputation) and he checked out the steeting head bearings.  Sure enough they were loose.  He adjusted the bearings and appologised, because he had put the front end on, out of the crate the bike came in.  I talked to several people that were old timers then and was told "pull in the clutch".  Your friend was very lucky.  It scared the S__t out of me!

[WamegoRob]

Back in 1966 I had a BSA 650 Rocket that got into a lock to lock (steering lock) wobble at 60+.  I just pulled in the clutch and it stopped.

Getting a hold of the clutch with the handlebars bouncing lock-to-lock must feel similar to riding a bull.

[dreamchaser]

Nope, but it does help to remove one of the forces involvet in the action and it gave my mind something to focus on besides utter terror.  My old beezer didn't have the power at hand to get the weight off of the front wheel and breaking would have put the wobble further in charge when the front wheel gained more traction.  I just got lucky!  (or was it devine intervention?)

[Mildew]

Priciate the replies. I had a slight wobble with my 205/55 tire over 100 mph but never with the 60.
I think his shock bushings are good on the Vaquero because the bike is only a year old. He did say his air pressure was down. That's got to be the problem because this is the first time he experienced this in over 12,000 miles and at least 7,000 from a car tire. I'll be checking my air pressure in the rear tire more often from now on.

[wdvalk]

had the same problem,never could get rid of it,went back to metzlers

[Jabba]

Front tire and pressure is a concern too.

12000 is enough IMO to wear out shock bushings regardless of age.

I have had headshake on my IS.  New front tire, and shock bushings cured it.

I believe that gripping the tank with your knees helps break the harmonic pattern as well.  I have had several bikes with chronic headshake issues.

Good luck to you guys.  Headshake is nothing too mess around with.  I had mine at 110 chasing Roadkill and Fudgie at one of the Whiskey Runs... glad to be here.

Jabba

[aslondon]

I had one on my 2000 Interstate a while back that went to a full width of a traffic lane at about 105. Took it to the dealer and they checked everything but initially wouldnt take it above speed limit. After much whining the Service manager who was a friend of mine took it up to speed and came back white as a sheet asking how I rode this thing - it scared the crap out of him.  They kept looking and found it was the Metzler tires. Metzler stepped up to the plate and told the dealer to give me whatever I wanted and send them the bill.  Problem solved!

Al
vrcc 4321