Jones Counter

It was developed in 1971 by Alan Jones to accurately measure the length of road running race courses.

One count typically corresponds to about 1/20 of a wheel revolution (this varies if a different gear ratio is used); this provides a resolution of about 10 cm in course length, although overall accuracy, depending on calibration and other factors, is lower, but normally better than 1 part in 1,000.

Created by Laurent Lacroix in 2000,[2][3] its distinguishing feature is a 27" rotary cable that allows the user to mount the Veeder-Root Counter on the handlebars.

To measure road-race courses, the counter is fitted to a bicycle between the left fork leg and the front wheel.

Before the counter is used, the bicycle must first be calibrated by being ridden on a straight section of road between marks whose separation has been accurately measured by steel tape.