Tank slapper

[Joesmoe]

Honda ST1300, also with shaft drive, also has a definite pull to the left.

@2012cliff what size are you running on your Touring ?

 

[2012cliff]

Honda ST1300, also with shaft drive, also has a definite pull to the left.

@2012cliff what size are you running on your Touring ?

I believe I have the stock size on the front and back. I could be wrong and as it is -25c tonight i dont feel like going outside. So ill check tomorrow and if it isnt stock I'll post the size.
Are you running a different size tire in the front?

 

[1olbull]

Yes, this is something that all shaft-driven bikes will exhibit to one degree or another, more technically known as counter-rotational force [centripetal force (I think) created by turning of the driveshaft].

cen·trip·e·tal force
(sĕn-trĭp′ĭ-tl)
The force that pulls an object moving in a circle toward the center of the circle and causes the object to follow a curving path. Earth's gravity acts as a centripetal force on the moon.
Did You Know? In one popular carnival ride, people stand with their backs against the wall of a cylindrical chamber. The chamber spins rapidly and then the floor drops out, but the riders remain pressed against the wall and don't fall down. Why? Most people would say that the reason people"stick" to the wall is because a centrifugal, or outward, force is pushing them against it. In actuality, there is no outward force, no matter how strongly the people on the ride may think they feel one. In fact, it's just the opposite: the riders are really subject to an inward, or centripetal, force. As the ride spins, it forces the riders to travel in a circle. Objects (including people) in motion tend to travel in a straight line at constant speed unless they're acted on by some external force. To make an object travel along a curved path, you have to keep forcing it toward the "inside" of the curve.The walls of the ride do just that, pushing the riders toward the center; the friction between the riders and the wall holds them up, so they seem to defy gravity.
This gyroscopic action is also known as "shaft effect" and "torque jacking"...

FYI and a little poke in fun, Amigo.
From my physics class at Texas A&M, I was learned that technically there really is no such thing as centripetal force.
No force pulls an object to the center of a radius. The spin of the cylinder creates a lateral force competing with the linear force. Once the wall rotates fast enough to develop more g-force (centrifugal) to the riders than their weight, the floor can drop without issue. The wall simply holds the folks in place and keeps them from flying away in a straight line.
As you stated, "Objects (including people) in motion tend to travel in a straight line at constant speed unless they're acted on by some external force" Newton's 1st Law. The wall acts like a string holding a ball that is being spun in a circle producing that "external" or lateral force. Cut the string and the ball flies straight, tangent to its path, not in a circle.
The wall does not actually force the peeps inward to the center, but produces lateral (external) force by its rotation.
In our vehicle world, lateral force is generated by the tires of a turning vehicle attempting to overcome the linear force holding it in a straight line. This produces centrifugal force (car turn left, but driver wants to move right).

 

[2012cliff]

I still say its the tire

 

[TURBO200R4]

had a problem like tank slap with the metz after tire ok.
just always always kept one hand on the bar till the tire wore out.
i to think bad tire or something happen when it was mounted.

 

[RKTNMYPKT]

I knew a guy named Filthy Phil for a while, I met him in a bar downtown, he said he was an ex Mongol, and would often show me pictures of him and the people he rode with to prove it.

We got along fine for months until one day he decided that I was H A, and that somehow I was going to do him harm,

He started yelling screaming calling me an a$$hole

Bartender told him to get the f#ck out .....

He got up walked out of the bar and I've never seen him since

 

[1olbull]

Note: A tank slapper is a high speed wobble.
I have experienced the no hands front end oscillation and, while NOT acceptable, it is easily corrected by placing hands back on the bars. Light-weight riders experience this more than us heavy-weights. Leaning forward over the bars can usually help correct this.
The tank slapper, or high speed wobble happens with hands on bars and is much more severe in Hz rate, usually caused by severe frame flex or a mechanical issue.
Just saying . . .
Low Speed Wobble? | Randakk's Blog

 

[RocketKev]

Ever since making the mistake of buying an '80's something Yamaha 900 Virago, every bike which I've considered purchasing, since that model, I've taken up to 100 KPH and taken my hands off the handlebars. I drove that Virago for several thousand kilometers and couldn't understand why my right shoulder was sore. The bike was purchased new and I was told by the Yamaha rep that they were aware of the problem but unfortunately there was nothing they could do. Since then, the only thing I can do is to never consider buying another Yamaha product.

 

[sleeves]

HI Phil, have you got a windscreen on (ranch-slider types)? they can cause this too, mine gets a shimmy with the screen on at about 80mph but not with it removed. Think its because I haven't got it aligned perfectly.

Also have had troubles in the past with other bikes have a steering wobble and traced it to the rear swing arm bushes, transmitting the slop to the front of the bike easy enough to check on smaller bikes not so much on the R3. Its a heavy bike but you should be able to take your hands off the bars without worry.

 

[sonny]

HI Phil, have you got a windscreen on (ranch-slider types)? they can cause this too, mine gets a shimmy with the screen on at about 80mph but not with it removed. Think its because I haven't got it aligned perfectly.

Also have had troubles in the past with other bikes have a steering wobble and traced it to the rear swing arm bushes, transmitting the slop to the front of the bike easy enough to check on smaller bikes not so much on the R3. Its a heavy bike but you should be able to take your hands off the bars without worry.

Yes indeed. Have a Harley fatboy and after 65,000 miles it had a wobble. Replaced the spacers with chrome ones and replaced the swing arm bushings and the wobble was gone.