Author |
Message |
Drkside79
| Posted on Monday, April 05, 2010 - 09:26 am: |
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So i have been hearing a lot about tank slappers recently. (mostly elsewhere) Is this something that happens often? Is it something that happens to the XBs? Other than braking to compress the front shock is there anything to do? |
Ft_bstrd
| Posted on Monday, April 05, 2010 - 09:36 am: |
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I've only experienced a partial one. I hit the high bank coming out of the last turn at Nashville Super Speedway to directly and deflected the front wheel for a little while until it righted itself. Other than that, I've never felt one. |
Paw
| Posted on Monday, April 05, 2010 - 09:51 am: |
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From what you are saying...I take this as you do not know what a tank slapper is...It is where your front tire is deflected to the left or to the right and it continues to deflect back and forth...It gets it's name from the handle bars slapping the the tank...Most of them happen when someone does a wheelie and brings the front end down with the tire turn to the left or right. |
Greg_e
| Posted on Monday, April 05, 2010 - 09:53 am: |
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I've not even felt the start of a slapper on my 9R, used to feel the start often on my old Katana. I think some of it has to do with the front end geometry. |
Paw
| Posted on Monday, April 05, 2010 - 09:55 am: |
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Here is a video of one from the front wheel getting lose. http://www.youtube.com/watch?v=LZ1srcQMa_0 |
Paw
| Posted on Monday, April 05, 2010 - 09:56 am: |
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And one after a wheelie this dude got lucky and save it his front end was turned to the left when he landed. http://www.youtube.com/watch?v=ZzNh0c2UyaQ&feature =related |
Drkside79
| Posted on Monday, April 05, 2010 - 09:58 am: |
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Well PAW I know what one is. (harmonic feedback caused by a bump) I just didn't know how common it is. |
Paw
| Posted on Monday, April 05, 2010 - 09:59 am: |
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This one after a wheelie turned out real bad. Happens at :50 His tire was turned to the right when he landed. http://www.youtube.com/watch?v=YD6jruSIELA&feature =related |
Paw
| Posted on Monday, April 05, 2010 - 10:04 am: |
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Geez take it easy Drkside79...Next time word your post better so we know you know what one is!!! Just trying to be helpful!!!!!!!!!!!!! |
Vtpeg
| Posted on Monday, April 05, 2010 - 10:09 am: |
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My '03 after a tank slapper. No warning just lock to lock.
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Drkside79
| Posted on Monday, April 05, 2010 - 10:31 am: |
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Paw my second post wasn't meant to be rude just was a clarification of what i was asking. Sorry for any misconception. |
Froggy
| Posted on Monday, April 05, 2010 - 10:35 am: |
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Due to the steering geometry on the Buells tank slappers are very uncommon. They can still happen though. |
Fast1075
| Posted on Monday, April 05, 2010 - 10:39 am: |
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You used to see a lot of tank slappers in street class dragracing before the major sanctioning bodies started requiring dampeners if the chassis is altered..people would "lower" the bikes by running the fork tubes way above the triple clamp...took away rake and trail...very dangerous... |
Xbimmer
| Posted on Monday, April 05, 2010 - 10:58 am: |
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The LAST thing you want to do is hit the front brake. Reduces front geometry which aggravates the situation. They used to be more common on bikes with better engines than frame tech. My brother got spit off a Z1 at 100 per once, I saw a kid slam onto the freeway on a GS450S after a slapper, my 750F1 tried it once on a rain grooved section of I-5. My R100S only did it on black ice twice but very briefly. Common advice back then was to try to hang on and push on the rear brake, and at least in my case that worked. |
Midknyte
| Posted on Monday, April 05, 2010 - 11:00 am: |
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Best article I've come across on the subject http://www.beginnerbikers.org/showthread.php?2905- Whats-a-Tankslapper&highlight=slapper "...Usually occuring when accelerating hard over bumpy pavement, a tankslapper ensues when the front tire becomes airborne, then regains traction outside the rear tire’s alignment. The resulting deflection bounces the tire off to one side, followed by another bounce in the opposite direction as it contacts the pavement again..." A bike, in motion, wants to stay up and keep moving in a straight line. A tankslapper occurs when the front wheel, having lost traction, comes back in contact with the tarmac "outside the rear tire’s alignment", or, outside of its' natural straight line desire. As it snaps back, if it bounces and overshoots in the other direction, it sets up a nasty oscilation as it comes back and tries right itself again. Viola - a tankslapper.} |
Wolfridgerider
| Posted on Monday, April 05, 2010 - 11:01 am: |
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We tell our students to adjust their weight toward the front of the bike... Lean over the tank and use your arms like shock absorbers (not stiff arm) and gently roll off the throttle. I have never had one on any Buell I have ever ridden on the street or the track. But my 2000 Road King would start to do it if I looked at it wrong while I was in a turn. I hear the new frame has fixed that. |
Ft_bstrd
| Posted on Monday, April 05, 2010 - 11:02 am: |
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Usually it's amplified by the rider trying to correct the problem. |
Buellkowski
| Posted on Monday, April 05, 2010 - 11:22 am: |
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+1 FB. I once rode a country road aggressively on my tuber (no damper) and happened upon a dog while coming around a bend. The oscillation started because of my reaction to the surprise. Braking only made it worse so I pulled in the clutch and coasted until the shaking stopped. Didn't turn into a full slapper; my guardian angel kept up with me that day. |
Sifo
| Posted on Monday, April 05, 2010 - 11:38 am: |
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I got a mild oscillation going once on my XB. I was way over due for a new front tire due to a back order on the tires I wanted. The tire had a good amount of cupping at that point. I let go of the bars stretch my arms while slowing for a stop sign around 45 mph. Settled right down as soon as I got a hand back on the bars though. Tried it a few more times with my hands just over the bars, and it would do the same thing again. Got the new tire on in a couple more days and never had that happen again. I think the XB chassis is stiff enough that it normally doesn't want to start that sort of oscillation. I think hitting the brakes is the wrong thing to do. Just backing off the throttle usually does the trick it you catch it early. |
Reepicheep
| Posted on Monday, April 05, 2010 - 12:36 pm: |
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I had a Yamaha Radian that would go into one any time you were off throttle downhill with hands off the bars. New steering head bearings helped fix that (and lots of other things as well). My M2 never did it. My 9sx has been rock solid, including jumping a curb leaned over on the throttle at mid ohio. Oops... glad that worked out! The Uly would feel like it was starting one when I would lean over with a 170 squared off dunlop on the rear and a sync on the front. That was just to get me home, once the sync was on the back, it was solid. It'll wobble a bit if the front tire comes up accidentally (it hear it can happen) and comes down a little off center... a few wobbles and its locked back in line. The uly is definitely more sensitive to doing it then the 9sx though. |
B00stzx3
| Posted on Monday, April 05, 2010 - 01:03 pm: |
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Never felt one on my 9R..... but those GPR stabilizers do look for nice. Woudl that solve the problem? |
Swordsman
| Posted on Monday, April 05, 2010 - 01:06 pm: |
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The only one I've ever had was when I rounded a blind curve on a narrow one lane road to discover it was actually a 90' turn and a sheer drop. In my sudden moment of panic I believe I jerked the bars and got a wobble started. I had just enough lane to ease up without running off the side, and it leveled out pretty quickly... only got maybe 3 or 4 skakes. Luckily, my instinct never tells me "brakes", it always says "less throttle". I have to think about brakes. ~SM |
Daveswan
| Posted on Monday, April 05, 2010 - 01:34 pm: |
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check out this recovery! http://www.youtube.com/watch?v=6Fa0GmdSN4A&feature =related |
Texastechx1
| Posted on Monday, April 05, 2010 - 02:00 pm: |
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i've had a few tank slappers, one on a 99 HD dyna low rider and a couple more on a few liter jap bikes. None on my X1 though or any XBs either. The best thing to do is accelerate... HARD. I know it sounds fishy and goes against everything your mind and gut feeling are telling you, but it works. Takes all the load off the front end so you can straighten everything out. |
Ft_bstrd
| Posted on Monday, April 05, 2010 - 02:08 pm: |
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90% of the time more throttle is the answer. 10% of the time more throttle ends the suspense. |
Texastechx1
| Posted on Monday, April 05, 2010 - 02:09 pm: |
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lol |
Natexlh1000
| Posted on Monday, April 05, 2010 - 02:26 pm: |
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The only time it happened to me really was on my 1979 XLH. I had firmed up the rear suspension all the way out with no alteration for damping. Went around an exit ramp at a high speed coming off the highway and it flopped side to side bad enough so that I lost my line and by the time I got it damped down to a controllable state, I was almost at the outside curb going less than 35! My recipe for tank slapper: Twist-o-matic forks that needed a rebuild, no rear damping, all the spring preload possible , tall bias ply tires on spokes and a 19 year old fresh from his KLR250. |
Xbimmer
| Posted on Monday, April 05, 2010 - 02:38 pm: |
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This is more the tank slapper, I feel for that guy... http://www.youtube.com/watch?v=XiKmPFo6xNA&feature =related |
Drkside79
| Posted on Monday, April 05, 2010 - 02:53 pm: |
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Dear God that was awful. Hit the gas my ass. |
Fast1075
| Posted on Monday, April 05, 2010 - 03:09 pm: |
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I had a front downtube break on a pass on HEAVILY modified H-2 Kawi in 1975 at the dragstrip...it broke at about 1000ft...went instantly into violent tank slappers. Me and the bike departed company at around 125 mph...Thank God they had haybailed the Armco barriers...Ruined a really nice set of Bates leathers and my favourite Bell Star helmet...no broken bones...just bruised all to hell... |