tank slapper

When a motorcycle shakes its head. The front forks going from lock to lock.

The pillion passenger on a motorcycle.

The aftermath of a very rare and extraordinary poo. A tank slapper requires the coming together of a unique arrangement of circumstances not encountered on a frequent basis.

Firstly the poo being ejected must be firm, ideally smooth, definitely not sticky and have some elastic properties.

Secondly the body from which the poo is being ejected, must be longitudinally centred and slightly forward on the pan. The sphincter must not be too slack or overly encumbered by anal beard, this is to ensure maximum velosity on exit and reduce any parasitic friction.

If these properties are met, the poo will launch out of the anus. It will hit the forward side of the pan, adjacent to the bowl water. Ricochet on to the back pan, leaving two perfectly vertical skid marks in front and behind the bowl water. This is a tank slapper.

When the fuel in a vehicle hits the inside of the tank hard enough to shake it, nearly always cause by making sudden, unplanned turns. Tank slapping is a symptom of bad driving.

Many cars use special baffles to help reduce this.

Can also include the rider's legs on a motorcycle.

see 'Tank Slapping'. The art of anal sex with a man in a doggy style.

A sudden oversteer in a car caused by the rear-end being unsettled in a corner. Usually happens if the accelerator is pressed too hard or too early on corner exit. May be unpredictable and needs delicate steering and pedal work to correct depending on severity

Term is originally used in motorcycling, but is used interchangeably with cars and racing

Tankslapper is when a car has sudden oversteer due to many different conditions depending on suspension or drivetrain setup.

One possible origin for the word is old WW2 tank crew vetetans taking careers as racing drivers during 1950s and dubbing the natural effect of inertia as a "tankslapper" as the weight of a tank usually centered around the rear due to storing ammunition.