:o
I'm not sure what happened, so I'm posting my experience for any input.
Riding my Bandit, I was on I80 east yesterday between Erie, PA and Buffalo, NY on my way to St. Catharines, Ontario. There had been a thunderstorm, but it slowed to a light drizzle. Needless to say the road was wet, and in particular there appeared to be water over a tar strip that covered the seam between the macadam of each lane.
I had just passed a tractor trailer and signaled and moved over into the right lane. As I moved right, just after crossing the center line, the rear wheel slid to the left and then a tank slapper set in. By luck or whatever, I gave it a little throttle to settle the tank slapper, and the bike straightened out and settled down. Catastrophe averted.
The only think I can think of is that I hydroplaned. Odd, since I've ridden thousands of miles on wet roads and I've never experienced anything like that. I'm running Michelin Pilot Road 2s with about 9000 miles and a little over 2mm of tread depth. I rather feel like I didn't learn much from my experience since I'm not too sure what (if anything) I did to initiate the rear wheel slide.
Thoughts? [popcorn]
Sounds like hydro and possibly combined with slippery paint lines. The two factors might well have added up to initiate your slide.
Did you experience a tank slapper or just some head shake?
Did the bars go full lock? If not, it was head shake.
All it would take is crossing some standing water at 65 mph to completely lose traction. If you were giving it any throttle at all at the time I would expect the rear tire to spin and it will usually slide out to one side or the other. Especially with tires as worn as yours.
Get new tires or don't go so fast in the rain (or both).
Quote from: ScottRNelson on August 10, 2009, 02:31:21 PM
Did you experience a tank slapper or just some head shake?
Did the bars go full lock? If not, it was head shake.
All it would take is crossing some standing water at 65 mph to completely lose traction. If you were giving it any throttle at all at the time I would expect the rear tire to spin and it will usually slide out to one side or the other. Especially with tires as worn as yours.
Get new tires or don't go so fast in the rain (or both).
Well, my hands hit the tank, so I guess it was just violent head shake.
Hmmm...like I said I was surprised since I've ridden so much in wet weather and I don't think my tires are that worn, but point taken. Perhaps I was twisting the throttle when the wheel spun.
BTW, I get about 12k miles from a PR2 rear and more from the front.
ive only had two of them, but if u get spit on the side of ur lip from being shaken, u just had a tank slapper.
i had a tank slapper at the same speed. torn open the steering head tube. if you did go lock to lock hard numerous times and it didn't highside you... consider yourself very lucky.
glad you faired well.
Quote from: pompetta on August 10, 2009, 05:30:53 PM
Well, my hands hit the tank, so I guess it was just violent head shake.
Okay, tank slapper.
It's just that I see a lot of posts where people experience a little bit of headshake and want to call it a tank slapper. Good job saving it.
I would still put the most blame on your worn rear tire.
Since I've never managed to get more than 4000 miles from a rear tire on any of the Ducatis that I've owned, 12,000 miles seems almost magical. I guess tires last longer if you ride at a steady speed. Or maybe the roads at your end of the country aren't so abrasive.
Quote from: ScottRNelson on August 11, 2009, 03:54:34 AM
Okay, tank slapper.
It's just that I see a lot of posts where people experience a little bit of headshake and want to call it a tank slapper. Good job saving it.
I would still put the most blame on your worn rear tire.
Since I've never managed to get more than 4000 miles from a rear tire on any of the Ducatis that I've owned, 12,000 miles seems almost magical. I guess tires last longer if you ride at a steady speed. Or maybe the roads at your end of the country aren't so abrasive.
I'm going to have to re-evaluate what "worn" is for my tires. These Michelins are on my Bandit, and 95% of the wear is due to riding the superslab.
so you have squared your tires off and it changes the handling.
Quote from: Raux on August 11, 2009, 08:45:25 AM
so you have squared your tires off and it changes the handling.
That's what I'm thinking, but since there's more tread on the edges of the tire, I'd think that shedding water would be efficient during a lane change.
Perhaps someone with more experience can comment on the effects of squared-off tires on wet weather riding.
Quote from: pompetta on August 11, 2009, 10:33:06 AM
That's what I'm thinking, but since there's more tread on the edges of the tire, I'd think that shedding water would be efficient during a lane change.
Perhaps someone with more experience can comment on the effects of squared-off tires on wet weather riding.
i can .. it sucks. that's why i got a new rear tire when i did.
next bike will have sport touring tires with dual compounds to give the center tread more time before squaring.
Pilot Road 2's are dual compound, and are somewhat magical tires. I like them a lot!
Isn't a tank slapper caused by an overwhelmed front suspension? I'm wondering if you may have slammed the throttle shut or braked hard when the back kicked out thus, transferring all of the weight onto the front. I'm thinking the combination of the tar strip, standing water, and sudden weight transfer overwhelmed the front suspension.
Quote from: Jetbrett on August 13, 2009, 11:21:14 AM
Isn't a tank slapper caused by an overwhelmed front suspension? I'm wondering if you may have slammed the throttle shut or braked hard when the back kicked out thus, transferring all of the weight onto the front. I'm thinking the combination of the tar strip, standing water, and sudden weight transfer overwhelmed the front suspension.
Most of the tankslappers that I've studied happened under acceleration or while headed uphill while turning just a tiny bit. The front end was light if anything.
Quote from: ScottRNelson on August 13, 2009, 12:22:00 PM
Most of the tankslappers that I've studied happened under acceleration or while headed uphill while turning just a tiny bit. The front end was light if anything.
same in my case. front end got light on a sweeping right hand highway on-ramp. city road constructors forget to put a sign about abrupt transition... new road (onramp) 2-3 inches HIGHER than old road (highway) with NO transition.
I'm probably not explaining it well. The suspension is overwhelmed due to not being able to compress and rebound fast enough for the conditions. Then again, I could be misinterpreting what I've read.
Quote from: Jetbrett on August 13, 2009, 01:10:29 PM
I'm probably not explaining it well. The suspension is overwhelmed due to not being able to compress and rebound fast enough for the conditions. Then again, I could be misinterpreting what I've read.
basically the way i experienced it.. was in a lean when the front unloaded and pretty much tucked under when it reloaded then started oscillating from lock to lock. if it had a steering damper or (now i know) had i unloaded it again by twisting the throttle it would have settled down... but as it was, i was thrown highside.
What seems to start many tank slappers is when the front wheel either completely loses traction due to a light front end, or has such a small amount of traction that the front wheel can turn a bit with very little pressure on the bars. When it touches back down and suddenly gets a whole lot of traction the front end tries to get back straight as quickly as possible. If there is no steering damper, the weight of the forks, wheel, bars, etc., cause it to overshoot, then it tries to correct itself again and things get worse very quickly. Tank slappers are very violent. I hope to never experience another one.
Quote from: Raux on August 13, 2009, 01:15:53 PM
basically the way i experienced it.. was in a lean when the front unloaded and pretty much tucked under when it reloaded then started oscillating from lock to lock. if it had a steering damper or (now i know) had i unloaded it again by twisting the throttle it would have settled down... but as it was, i was thrown highside.
A steering damper would help avoid a tank slapper?
avoid or reduce the violent nature. a SOUND investment in a bike that has a tendency to be loose up front.
Quote from: BumbleB on August 16, 2009, 09:19:22 PM
A steering damper would help avoid a tank slapper?
I'm certain that a steering damper would have prevented the tank slapper that I experienced in 2003. I know of a few other cases of Monster tank slappers where a steering damper most likely would have prevented it as well.
Especially on the older Monsters, a steering damper can make a huge difference.
Quote from: Jetbrett on August 13, 2009, 01:10:29 PM
I'm probably not explaining it well. The suspension is overwhelmed due to not being able to compress and rebound fast enough for the conditions. Then again, I could be misinterpreting what I've read.
Tank slappers/headshake are not front suspension issues. As stated above it is the front tire out of alignment with the bike's direction of travel. The front then grips and tries to return to the path of least resistance(rolling inline with the bike), but over corrects again and again. Taking weight off the tire by adding throttle allows it to correct itself. Very hard to do in the moment b/c the natural instinct is to release the throttle.
Or the rear can step out so far enough to one side or the other, regain traction and shake the bike back and forth so violently that the frame will contact the bars. I believe this is what Pompetta experienced since he was not doing anything to lighten or cross up the front. His rear tire hydroplaned to one side, then regained traction.
Examples of both in a matter of 2 sec.
Close Shave! (http://www.youtube.com/watch?v=HtjQ4SK4GXk&feature=related#normal)
The only true tank slapper I had came on my CBR when I hit a pot hole doing about 70. The handle bar went lock to lock several times. It happened so fast I had no time to react and I have no idea how I held on. My wrists got pretty banged up and I burned my leg on my exhaust when my feet came off the pegs. It seemed like the pot hole probably caused the front wheel to jerk to the side and chaos ensued. I think the craziest part is that the chassis sorted itself out somehow and I didn't crash.
Tank slappers and tornadoes... they come out of nowhere and just make the beast with two backs shit up. I hope I never have one, and I'm definitely considering purchasing a steering damper as an upcoming mod. It won't always prevent one, but it doesn't hurt to have it.