Jones counter
From WikiRun
A Jones counter is a device which attaches to a bicycle for use in measuring race courses. It was invited by Alan Jones in 1970. It consists of an automobile odometer which is mounted so that its gear teeth engage a bracket attached to a bicycle wheel. Because the digits on the odometer do not represent an exact distance, the Jones counter must be calibrated before each use to reflect current temperatures and bicycle tire pressures.[1]
External links
References
- ↑ http://www.jonescounter.com/2.html Retrieved 2008-07-18.