GSXR 1000 Tank Slapper HELP

tjdobb

tjdobb

Donating Member
Registered
A friend of mine just bought a 1000 and while out riding two weeks ago we did a little roll on race up to +/- 140 or so. I let off first and when he passed me he said he was shifting gears and all of a sudden he had a hell of a tank slapper going for a few seconds. Scared the hell out of me and him. We pulled over and checked everything out (tire pressure, bolts, etc.) and everything looked ok. We just blew it off as a fluke. He is an experienced rider or he probably would have been down. Well yesterday I was out riding with him again with some other friends and he did a roll on with a 954 RR and the same thing happened to him again around the same speed and when he was shifting. Any ideas what would cause this? Maybe the front tire out of balance or a bad tire. Any help would be appreciated before this gets him into trouble. Thanks for any suggestions.
 
I've never experienced tank slap (thank God) but two guys I ride with have. One guy has a "07" ZX 10 and the other a Kawi 636.
I'm here to hear the reason why some bikes get tank slap.
lurk.gif

Shawn
 
My busa does that. It dosent ever jump out too far. Under hard acceleration/high speed shifting it will wobble hard enough to see the headlight move about the road. I just let off some and try not to go that fast.
 
I've only had that problem by causing it... (over-breaking in emergency) and one time when I got on her pretty hard passing a kawi, (got the front REALLY light and hit a few bumps in the road on a slight curve...

In all cases I just rode it out...
firedevil.gif

beerchug.gif
 
A front tire that has worn itself out of whack or if it's out of round will do that. I had an almost new Shinko front tire(R003) do that to me last week. The more i ran it, the more i felt it and if i let goof the bars it would shake itself into a tankslapper. A quick swap back to the old Diablo tire i was using solved it. Now smooth as glass.
 
Aside the usual things to check (tire pressure, tire balancing, condition of front tire, no worn bearings or loose bushings, (front) shocks in good shape and properly aligned, shock settings, steering dampers settings) I am suggestion one more:

If your friend is of a fairly light stature and has a more upright seating position, he may be catching a lot of headwind, shifting the weight on the bike rearwards. He also shouldn't have to 'pull' the handlebars to stay in his seat during rapid acceleration. In high rpm upshifting he may both chop the throttle prior to pressing the clutch and rev the rpm prior to letting out (snapping) the clutch. The first will slightly compress the front shocks, the second slightly release - the combination resulting in a lifting of the front tire, ever so slightly, which could start the wobble when it bounces (compresses) back to the road surface. The tire does not have to lose contact with the road for this effect to start. Your friend should try to tuck more forwards and ease throttle/clutch control.
 
tell him to put a GPR steering stabilizer on it and call it a day. Same thing happened to a friend of mine to his 2005 GSXR-1000 and the problem went away after the new GPR.
 
to me it sounds like the front wheel is skipping. Under hard acceleration your body wieght+ the bikes weight want to move back putting more of the wieght on the rear tire. Thus slightly lifting all the downforce off the front tire, Causing a ever so slight wheelie effect making the front end to do a nasty wobble. My old R6 was terrible for it. A steering damper helped that problem on that bike
Check everything out again, but next time you try it put more of your body weight as far forward as up can to help keep the front end down.
See if that works.
 
GMbusa @ Apr. 20 2008 said:
A front tire that has worn itself out of whack or if it's out of round will do that. I had an almost new Shinko front tire(R003) do that to me last week. The more i ran it, the more i felt it and if i let goof the bars it would shake itself into a tankslapper. A quick swap back to the old Diablo tire i was using solved it. Now smooth as glass.
Click to expand...
+1 tire....
 
If it is doing it while or as he is shifting could he be pulling on the clutch side of the bar and initiating it?? Just a thought since both times were under hard accel and while shifting causing the front to be light and more susceptible to torque on bars.
 
Same guy, same reaction on two different bikes........rider error of some sort....he's causing it.....I get a wiggle on a too-hot downshift for the gear, standard shimmy, weight the pegs, keep the bar loading even...stops as soon as I grab traction.....tank slapper for this guy, is in something he's either doing or not doing.....
 
2 different bikes? guess I missed that, pretty much narrows the possibles down...
 
Same bike and brand new only 600 miles on it. Two different times and different roads. Iam wondering if the tire from the factory is just a bad tire. Or the light wieght rider theory might be the issue. He only pushing 140 lbs. Maybe the suspension setup is not set up correctly either! Well thanks for the ideas guys. I wonder if using heavier oil in the factory stabilizer will help like some of the busa's.
 
needs more weight over the front 1/2 of the bike....sit too far back, "pull up" or sit up too early and the aerodynamics cause the front to lift.
try dropping the front end about 10~20mm ....or 1/2". you can also stiffen the rear to help keep the bike from rocking to the rear.

just some thoughts.
 
Do what i did, jsck up the front wheel off the ground and spin it. You might have to unbolt the two calipers to get the wheel to spin freely. That's how i found my out of round tire. It hopped an 1/8th inch. By all means it the bike is more than a couple years old and/or the owner is known for wheelies and such, check the steering head bearings and anything related.
 
topgun61 @ Apr. 20 2008 said:
tell him to put a GPR steering stabilizer on it and call it a day. Same thing happened to a friend of mine to his 2005 GSXR-1000 and the problem went away after the new GPR.
Click to expand...
+1

Scott's Damper on all my bikes. I used to get some headshake pulling hard out of the corners, none at all w/ the damper.
 
You must log in or register to reply here.

Similar threads

D
Tank slappers
Replies
8
Views
732
Revlis
Revlis
D
Tank slappers, how common?
Replies
5
Views
2,065
dhart
D
rc51ny
Tank slapper kit
Replies
10
Views
895
bigoltool
bigoltool
SmokeKingOfCali99Hayabusa
2008 Gsxr 1000 Wont Start. Need Help !!
Replies
17
Views
4,888
Berlin Germany
Berlin Germany
T
Hayabusa vs. GSXR 1000
2 3
Replies
42
Views
65,099
WuzzaCBXRider
WuzzaCBXRider
Back
Top