The Run Canada Committee
Road Race Course Measurement Procedures

APPENDIX C

Example of Course Measurement

Calibrating the Bicycle

You take your trusty bicycle with tires fully inflated and your pack of equipment out to the calibration course you previously submitted for certification. It is 7:15 AM. You determine the temperature as before (53 °F) and ride the bicycle around for roughly five minutes to warm the tires up. You record the time and temperature.

You position the front axle of the bicycle over the start point on the calibration course. You record the start count as 116091. You ride the calibration course, carrying your equipment. You carefully stop the bicycle with the front axle positioned directly over the end point. You record the finish count as 125499.

You then repeat this procedure three more times, recording the start and finish counts. Each time you reverse direction, you freeze the front wheel with the handbrake before turning the bike around. In this way, your finish count for one ride is your start count for the next ride. This isn't necessary but makes it slightly easier to calculate your average count.

You now sit down and fill in the first part of the Bicycle Calibration Data Sheet. The average pre-measurement count works out to be 9407.25 counts. If you had been using an odd-distance calibration course, you'd have to convert this to one kilometer (or one mile), but in your case, your calibration course is already one kilometer. You multiply your average pre-measurement count by 1.001 to obtain your working constant of 9416.6572 counts per kilometer. You raise this to 9417 and will use this value for preliminary course markings. Also, since you will be marking some mile splits, you multiply the 9416.6572 figure by the conversion factor of 1.609344 (see Appendix E) to obtain a mile constant of 15154.64 which is raised to 15155 counts per mile.

You now measure the course (see next section).

After you have completed your two measurements of the race course, you return to the calibration course. It is now 10:30 AM. You check the temperature and record 63 °F.

You calibrate the bicycle just as you did for the pre-measurement calibration with four rides. This time the average count is 9399.75. You multiply this by 1.001 to obtain your finish constant of 9409.1497 which is raised to 9410 counts per kilometer.

Since the finish constant is smaller than the working constant, the constant for the day is taken to be the working constant or 9417 counts per kilometer. If you start your measurements in the early morning, you will generally find your working constant to be larger than your finish constant. This means that the preliminary course marks will not need to be adjusted for the change in the bicycle calibration.

Updated: 15-01-2009