Tank Slap
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The worst tank slapper I ever had was racing a 86 Suzuki GSXR750 at Rockingham. I had gone through the chicane on the straight and was under full acceleration on the highbank. I crossed over a paint stripe (back when Rockingham had paint stripes on the highbanks). The bars were instantly yanked out of my hands and began hitting the stops back anf forth. Somehow I regained composure and control of the bike and continued on through the race. That was the first time I had experienced a full on tank slapper. I had a steering damper on the bike before the next race weekend.
The amount of down force on the suspension is incredible on a high bank running north of 140. That same weekend on the high bank a guy racing a gixxer with another guy drafting him ground through the oil line (the old gixxers were oil cooled and the line ran from the oil cooler under the frame). Both of the guys went down and into the wall. I just knew thet were dead but they got up and hobbled to the bottom of the track!
The amount of down force on the suspension is incredible on a high bank running north of 140. That same weekend on the high bank a guy racing a gixxer with another guy drafting him ground through the oil line (the old gixxers were oil cooled and the line ran from the oil cooler under the frame). Both of the guys went down and into the wall. I just knew thet were dead but they got up and hobbled to the bottom of the track!
Another!
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i added 40 weight motor oil, seems good for me. i can notice a difference.
That's interesting!
Do you have any references to back up that theory?
cheers
ken
Head shake and maybe on to a tank slapper can be caused even by a feathered front tire or easily by one that isn't grooved in the middle. Especially on a sport rake undampened bike! Ever heard of a tank slapper on a chopper. Bandit 1200 with Mich Macs on it almost killed people. The Busa must have more of a touring rake. Maybe why we lack a bit in the corners!
Oh and why is it the Pro riders just twist go! when you see it happen on the AMA races? I have never had a HINT OF HEAD SHAKE ON MY Commuting Busa! And I ran the BT56 front tire out being feathered, which would not been doable on the Bandit.
Bad Idea! Call Scott Performance (818) 248-6747 and chat with them or just read the instructions that came with your rotary damper.
So why didn't you remove the stock damper, once you installed the Scott damper???
me? nah, i don't have direct evidence,That's interesting!
Do you have any references to back up that theory?
cheers
ken
but if its the gyroscopic effect, which starts the
head shake, then this ought to stop it ...
http://www.reverserotatingrotors.com/
and a claim he makes is:
#2 No Tank Slap
It is impossible for a motorcycle that is equipped with
reverse rotating rotors to experience wheel wobble or tank
slap.
aside from that tho, i sometimes stare at the slapper videos
of people doin wheelies -- before they land --
and see the head shake of the front wheel while
its in the air and it sure seems like it.
Thanks for the link!me? nah, i don't have direct evidence,That's interesting!
Do you have any references to back up that theory?
cheers
ken
but if its the gyroscopic effect, which starts the
head shake, then this ought to stop it ...
http://www.reverserotatingrotors.com/
and a claim he makes is:
#2 No Tank Slap
It is impossible for a motorcycle that is equipped with
reverse rotating rotors to experience wheel wobble or tank
slap.
aside from that tho, i sometimes stare at the slapper videos
of people doin wheelies -- before they land --
and see the head shake of the front wheel while
its in the air and it sure seems like it.
Bike Physics fascinates me.
cheers
ken
+1
I get occasional headshake with the Gixx on WOT, 130 mph off-camber turns with a slightly bumpy surface. But staying on the gas and keeping a very light grip on the handlebars will prevent it (99.9% of the time) from becoming serious tankslappers.
Keith Code mentions that a little headshake is actually good because the gyro effect is helping stabilize the rest of the bike while assisting the front end to find traction and regain stability. What's also very true is tankslappers are usually rider error (i.e. gripping the handlebars too tight and not using the legs to anchor/pivot. As long as the bearings in the steering head are in good shape, stock damper in perfect working order, suspension set up to rider weight/riding style-there shouldn't be any issues with tankslappers.
Had a little headshake with the Busa at a trackday, but never once experienced it on the street.
That added weight is making you slower...
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