The Jones Counter is a type of bicycle

odometer An odometer or odograph is an instrument used for measuring the distance traveled by a vehicle, such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two (electromechanical). The noun derives from ancient Gr ...

which adds the function of a

surveyor's wheel A surveyor's wheel, also called a clickwheel, hodometer, waywiser, trundle wheel, measuring wheel or perambulator is a device for measuring distance. Origin The origins of the surveyor's wheel are connected to the origins of the odometer. W ...

to a bicycle. It was developed in 1971 by Alan Jones to accurately measure the length of

road running Road running is the sport of running on a measured course over an established road. This differs from track and field on a regular track and cross country running over natural terrain. These events are usually classified as long-distance ru ...

race courses. The counter has gears that drive a mechanical digital counter. 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. Almost all road running courses in the world are measured with this device. The Jones Counter has been used to measure all Olympic Marathon courses since the

1976 Montreal Olympics The 1976 Summer Olympics (), officially known as the Games of the XXI Olympiad () and officially branded as Montreal 1976 (), were an international multi-sport event held from July 17 to August 1, 1976, in Montreal, Quebec, Canada. Montreal w ...

except for the

1980 Moscow Olympics The 1980 Summer Olympics (), officially known as the Games of the XXII Olympiad () and officially branded as Moscow 1980 (), were an international multi-sport event held from 19 July to 3 August 1980 in Moscow, Soviet Union, in present-day Russ ...

. In addition, it has often been used to measure Olympic Road Race Walking Courses.

Models

Clain Jones Counter

The original production version was manufactured by Alan Jones's son Clain from 1973 to 1982. The gearing produces 20 counts per revolution of the bicycle wheel.

NYRRC Jones Counter

Production was taken over by

New York Road Runners New York Road Runners (NYRR) is a non-profit running organization based in New York City whose mission is to help and inspire people through running. It was founded in 1958 by Ted Corbitt with 47 members and has since grown to a membership of more ...

from 1983 to approximately 1990.

Jones-Oerth Counter

Paul Oerth took up production in approximately 1990 and continued to about 2006. These models have a different gear ratio (260/11 counts per wheel revolution). In 2006, production of the necessary gears ceased, and an alternative plastic-encapsulated set of gears was introduced. This was short-lived, and the Oerth model went out of production.

Jones-Oerth-Lacroix Counter

The JOL counter is a variation of the Jones-Oerth model. Created by Laurent Lacroix in 2000, its distinguishing feature is a 27" rotary cable that allows the user to mount the Veeder-Root Counter on the handlebars.

Jones Counter model JR

Development of a new model started in 2007. The first production units became available in April 2008 and were used for the measurement of the

London Marathon The London Marathon (also known as the TCS London Marathon for sponsorship reasons) is an annual marathon held in London, England. Founded by athletes Chris Brasher and John Disley in 1981, it is typically held in April, although it moved to Oct ...

, which took place on April 13, 2008. The gearing (260/11 counts per wheel revolution) is identical to that of the Jones-Oerth model.

Use for measuring road-race courses

Jones-Counter- Einsatz und Anwendung am Fahrrad zur Streckenvermessung

To measure road-race courses, the counter is fitted to a bicycle between the left fork leg and the front wheel.Picture in course measurement lesson
/ref> The tab or tabs on the large ring gear engage with the spokes, thus providing drive to a Veeder-Root counter. 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. A calibration can then be calculated in terms of counts per kilometer. Next, the bicycle is ridden over the race course to determine its length. Finally, the bicycle is recalibrated by riding again over the calibration distance. This is done to check for changes in bicycle-wheel diameter due to temperature changes, air leakage, and other causes.

References

External links

*
The Measurement of Road Race Courses
' (handbook of the

IAAF World Athletics, formerly known as the International Amateur Athletic Federation and International Association of Athletics Federations and formerly abbreviated as the IAAF, is the international sports governing body, governing body for the sport ...

) Counting instruments Sport of athletics terminology