Pressure hose

A pressure hose is a rubber timing hose laid across the road. When your front wheel rolls over it, a pulse of air pressure triggers the timing device.

How the measurement works

Unlike a light barrier, the hose reacts to the tyre, not the bumper. The timing point is your front wheel. That is the same for every crew, however long the front overhang of the car. Many organisers time to the hundredth of a second this way.

How to spot one

The hose is usually easy to see, often with a marshal and a small timing box by the road. At a secret check it may be placed so that you only see it late, for example just after a bend.

Practical tips

• Roll over the hose at a steady speed, not at walking pace and not with a jolt.
• If you time yourself, take the time when the front wheel touches the hose. A mark on the side window that lines up with your front wheel helps.
• Two hoses in a row are normal. Some systems use the second one as a backup or to detect direction.