HIGH SPEED TANK SLAPPER....need help fast!!!

[night rider]

:cry: I just had my first Rocket 111 high speed +125 MPH wobble/weave that was headed for a tank slapper. I have lost all confidence in Black Beast.
I checked the tire pressure 39/42 PSI and headed up stream once again passing +100 MPH only to feel the bike start to slowly rock back and forth turning into a weave and then a high speed wobble.

I really need some opinions as the dealer seems to want to ease out of a fix saying it is from the handle bar mounted Corbin Fleetliner faring. I told him I have repeatedly exceeded 130 MPH fully loaded and two up before without any trouble.

I just had a new rear tire put on before Americade. A while ago about 2000 miles I had installed new Progressive 440 rear shocks with new Progressive front fork springs with heavier fork oil, new front wheel bearings and a new front tire and the steering stem bearings checked and greased. I did all of this because at that time I had a low speed wobble when passing down thru 45 MPH hands off with the faring on or removed. The new front tire under warranty fixed this problem.

This new wobble at high speeds has me worried :x Can anyone shed some light on the problem. Help!!!! Thanks in advance.

Chriss
NightRider

 

[night rider]

Chriss

Has the angle of your fairing/windshield changed? I'm sure you are familiar with concept of center of pressure.

hombre

Hombre:
I remember your past posts on this subject and do understand the theory and the principle you are referring to. I have been to speed with the fleetliner on without any weave or wobble and no recent changes have been made?

I do think you are right regarding the steering stem bearings as they do seem loose.

I am going to remove the Corbin Beetle bags, Fleetliner faring and Givi top box and give it a go one more time.
Thanks.

Chriss
NightRider

 

[dragline708]

Chriss ,

" steering stem bearings as they do seem loose "

I read a post on another forum , that talked about
them , and they could cause a wobble.

Wish I could remember where it was, I'd copy & paste it

my2cents
wayne

 

[night rider]

Hi Todd:
I think what started all the trouble was that high speed +130MPH loaded 2-up pass between you and G-Man during the PA salvo. Actually Black beast was rock solid during that run, go figure :?:

The only real change recently has been the new rear tire? After the rain stops I will check to see if the new rear tire has been mounted in the correct direction.

Also I think Hombres suggestion regarding the steering stem bearings will be the first thing I will have the dealer check.

Thanks for the info. Hope all is well.

Chriss
NightRider

 

[night rider]

Thanks Wayne:
Any help is well appreciated :wink:

Chriss
NightRider

 

[dragline708]

chriss this talks some about it all

http://en.wikipedia.org/wiki/Speed_wobble


wayne

 

[TurboFan]

Check the steering stem yourself! Then have the dealer check it. And if necessary get another dealer. Lift the bike by the center, (engine) and secure it, solidly. Then try to lift the front wheel. Can you cause any little clunk in the steering head? Seems a crude test, (and maybe many of my bikes have been real junkers) but it has been all that was needed for me on more than one bike to find that the steering head was loose.

 

[night rider]

Wayne:
Good link, I never thought to look there, thanks.

My wobble seems to start like a slow weave or banking oscillation. Even at low speeds it becomes very hard to hold an exact straight line, seems to hunt or wander. I still can ride 'hands off' at any speed below 90 MPH the wobble point?

First I thought it was my CB antenna oscillating/wiping back and forth driving the rear to wobble. A later check proved not to be so.

I am really disappointed and truthfully I am concerned. My last high speed crash left a big hole in the ground. :?

Chriss
NightRider

 

[yogi1]

Chriss, the way you are describing it, I'd say it's a 90% chance that it's the head bearings. Mine were loose at about the 10K mark, and I tightened them right before the Rocket went down the road!

BTW: how's the C14??

 

[houkster]

Why would you want to go 125+ with a passenger? The few times I've gotten in the 120 indicated range all I could think of is: 'Am I nuts?'. I'm surprised how long it takes to get from 110 to 120. Figured this beast would get there quicker, without giving me much chance to ponder why I'm doing it! On my prev. bike (Moto Guzzi 2001 Calif. Special) I had a real fun - almost full tank slapper, twice in 5 miles. Was in the desert between Barstow Calif. and Needles with a new taller windscreen on that I'd just bought for the trip. Between that and 90mph and a solid headwind and full bags and little drop-offs between lanes on the asphalt, I got to experience head shake boogie. Changed back to my 'summer' sized screen and never experienced it again. If you have any kind of face shield on your helmet, you don't need those big windscreens as far as I'm concerned.