Last week, we stopped at the letter N in our A to Z of bike terms. This week, we continue with our list of unusual biker terms.

ONWARD WITH O

Orchard Gudang - The improvised 'circuit' used by illegal racers along Orchard Road. Another favourite location is 40 Tiang, or 40 lamp posts, at Lim Chu Kang.

Oil cooling - An engine cooled by its oil.

O-ring chain - A motorcycle chain with rings made of rubber fitted between links. O-ring motorcycle chains seal in the lubricant and repel dirt, prolonging their life.

Overhead camshaft - Camshaft mounted in the cylinder head above the pistons. In a single-overhead-cam (SOHC) layout, one camshaft powers all of the valves in a cylinder head.

Pak Haji - Normally refers to a man who has completed his Haj. They traditionally dress in white, which is why this is biker slang for the men in white - traffic cops.

Pinned - Refers to bikers going full throttle.

Piston - The part which compresses the gases in the cylinders. With every 'explosion' in a cylinder, the piston is forced downwards and turns the crankshaft.

Pre-load - Compression of a suspension spring to take extra loads or for a harder or softer ride.

Power band - Also known as the sweet spot where your engine produces the maximum power as you rev the bike.

Power slide - Sliding the bike sideways while accelerating.

Rake - The angle of the steering head.

Roost - The spray of sand and mud leaving the rear wheel of a dirt bike during acceleration.

Scraping - When riders bank their bikes, their footpegs often scrape against the tarmac producing showers of sparks.

Scrambler - Another term to describe a dirt bike.

Shroud - The plastic part on the side of a dirt bike's fuel tank, which protects the radiator.

Sprockets - Gears on the rear wheel and countershaft.

Superman - A trick executed by freestyle motocross (FMX) stunt riders. The rider launches from a ramp. While airborne, he temporarily releases his grip on the bike and poses a la Superman in flight.

Swingarm - The section of the motorcycle which connects the rear wheel to the chassis. Unlike conventional swingarms, a single-sided swingarm is used by the Ducati 916 superbike.

Tank-slapper - A severe wobbling of the handle bars due to poor suspension set-up. The 'headshake' gets more violent with increases in speed.

Trackdays - Days which are spent riding at race circuits.

Torque - A measure of engine flexibility, measured in Newton metres (Nm).

Trail - The distance from the front tyre contact patch (the point the tyre rests on the ground) to the line drawn down the forks to the ground.

Trailing - Dirt-riding in jungle or forest terrain.

Undertray - The back section of a sports bike which holds the brake and signal lights.

Valve - Either exhaust or inlet, which allow gases into or out of the cylinders.

V-twin - An engine configuration which has two cylinders lined in a V. Harley-Davidson and Ducati motorcycles come with V-twin engines.

Wheelbase - The distance between the front and rear axles. Longer wheelbases offer a more stable ride, while bikes with a shorter wheelbase turn quicker into corners.

Wheelie - Riding on only the rear wheel.

Now you know your A-B-Cs, next time won't you sing with glee?

HAVE A SAFE NEW YEAR

'If you drink, don't drive. Ride instead.' This is a bad biker joke which usually makes the rounds during festive seasons.

But the sad truth is that bikers die when they hit the bottle and the throttle.

From January to November this year, 24 people died in drink-driving fatalities - 15 of those were motorcyclists and their pillions.

Commander Traffic Police, Deputy Assistant Commissioner Ng Guat Ting, said: 'You may think that you are still sober enough to drive or ride after drinking, but we have seen too many cases where drink drivers or riders caused the deaths of their friends and loved ones.'