I. Introduction

        For more than thirty years the mechanical Jones counter has been the predominant wheel revolution counter used in the measurement of road-racing courses by the bicycle method. Each wheel revolution produces a count of 20 on the meter and so wheel revolutions can easily be read to 0.05 revs, an accuracy that is more than sufficient for course measurement. Despite the meter's extreme ruggedness and reliability, it is astonishing  that in this age of rapid change in technology nothing has come along to overcome its obvious shortcomings.

    The most obvious shortcoming is  the poor readability of the counter display. Digits are only 4 mm high and the counter is mounted on the wheel axel at right angles to the normal direction of reading and far away from the measurer's eyes while bicycling. It is especially difficult to read a digit that is in the process of transitioning to another digit. Road safety is obviously compromised while the measurer looking down at a difficult-to-read display. Recently, Laurent Lacroix has developed a modification of the meter in which the gearing on the axel is connected through a cable to the counter mounted on the handlebars. This modification solves some of the readability problems, but at increased cost, increased complexity, and possibly reduced reliability.

    A major disadvantage is that the counter cannot be zeroed before a ride. Consequently the measurer cannot get a direct readout of distance traveled and must record readings before and after the ride and then perform a subtraction. In laying out a series of  equal splits, the measurer cannot repeatedly use  the same split value, but before the ride must prepare a table with the calculated meter reading for each split.

    Because the counter generates 20 counts for every wheel revolution, the measurer has to read and manipulate large numbers thus increasing the chance of error. This possibility of error originally created doubts about the acceptance of the meter.

    A minor annoyance is that eventually the counter reaches 100,000 but records this as 00000 (wrap-around), and so the measurer has to keep track of this for his calculations. The use of counters with six digits instead of five reduces the problem but does not eliminate it.

    Although with lubrication the problem can be reduced considerably, the counter is very noisy and creates a lot of drag. Therefore, if the measurer has a high performance bicycle and rides a lot, he has the nuisance of mounting and demounting the meter for doing course measurement.

    Even measurers who are not bothered by degradation of bicycle performance probably should remove the counter when it is not being used for measurement because, despite its ruggedness, it does wear out and get damaged. A former NC state certifier once had to replace the counter three times in one year.

    Replacement may soon not be an option as it is likely that manufacture of the component parts of the counter will be discontinued. Indeed, the original gearing that produced 20 counts per revolution is no longer made and has had to be replaced with one that gives 23.6363.

   The above shortcomings of the Jones counter prompted the presently described modification of electronic cyclocomputers as counters. Precise synchronization with a graduated wheel rim allows measurement down to less than 0.01 rev equivalent to 0.1 of a  count on the Jones. The measurer need only read Sections II, III, V and XIV-1 to get a quick start in using them in course measurement.