I was just thinking that I only know a couple of people who have experienced a tank slapper.
One was on a modified Z1 that was set up for drag racing back in the 70s. The front end had just been modified and at about the end of the quarter at about 155 mph from what I can remember he went into a tank slapper and ran off the end of the strip before getting it back under control. The front end was changed back to stock before the bike was raced again.
Another was on a MotoGuzzi California II. It happened while riding on a two-lane highway that was pretty rough. He was riding at about 80 and a tank slapper started that he couldn't get back under control and ended up dumping the bike at about 60 resulting in serious injuries. Later the cause was determined to be a combination of road conditions, worn steering head bearings, and worn wheel bearings.
Head Shake
Similar to a tank slapper only a little less violent. Usually a quick shaking of the handlebars is all that results.
* EXUP Brotherhood's glossary of terms
Tankslapper
A violent repetitive swinging of the handle bars from left full lock to right full lock. Very scary to new riders, or anybody of any riding level. Some result in crashing but you can ride them out. Firstly, one of the best ways to avoid having one is to not strangle the bars when you ride. Don't grip them like you're trying to strangle your mother-in-law. A nice relaxed grip prevents many a tank slapper. If you happen to have a violent tank slapper, the best advice is to ride it out - DON'T ROLL OFF THE GAS!. If you are able to ride it out, immediately check your front brakes (pull the lever and pump them up). Violent slappers can spread the pads in the calipers, and you may need one or two pulls on the lever to bring the brakes back to full power.
* EXUP Brotherhood's glossary of terms
This is really a quite different thing than a shimmy or a headshake.
I have only witnessed the one that happened at the strip. I have experienced head shake when test riding a bike that needed a lot of work and experienced various forms of shimmies on many bikes but I personally hope that I never experience a tank slapper.
I have heard discussions about tank slappers and been to AMA safety clinics where they were discussed but they do not seem to really be that common on the street. However, it is probably a good thing for people to know something about as a little knowledge may help in the event we ever experience one. Most of the discussions of tank slappers were concerned with bikes either pushed way beyond their limits or with modifications that altered the steering geometry.
I had an H2 Kawasaki that I used to run at the strip in the seventies and a sever headshake was enough to keep me from messing around with the bikes rake and trail.
Mike
Comment