A few weeks ago I posted a note about a mechanical odometer that I had recently acquired. That odometer, a Kanto Seiki, was a mechanical odometer that was available in the early 1970s as a substitute for the Halda Tripmaster. A problem with the Kanto Seiki odometer is that it can not be calibrated itself. The correction or calibration has to be done externally to the odometer.
Kanto Seiki Odometer
I have this problem to a smaller extent with my other mechanical odometers such as the Halda Speedpilot and the Hemo Trip Taeller. These odometers are calibrated by turning screws which is a procedure that not as well defined or precise.
The Hemo Trip Taeller Odometer
This past week I acquired a speedometer/odometer correction box which will go along way to resolving the calibration problems with these odometers.
Speedometer/Odometer Correction Box
This device allows for the installation of internal gears that will adjust the rotation of the speedometer/odometer cable.
Inside View of the Speedometer/Odometer Correction Box
The device comes with a set of gears that can be installed inside the box that will change the output cable rotation speed.
Gears for the Speedometer/Odometer Correction Box
The device comes with a table which shows which gears to install based on the factor.
This speedometer/odometer correction box was originally sold by a rally equipment business, “Competition Limited” in Dearbon, Michigan. Competition Unlimited prepared the calibration table for the correction box. Competition Limited was one of the major rally equipment businesses in the 1970s and 1980s. It was run a well-known and successful SCCA Pro-Rally competitor, Gene Henderson.
Over the upcoming months I will be using this device to get comfortable with its usage. I am interested in how long it takes to adjust the speedometer/odometer correction box. In many of today’s rallies, the time allowed for odometer calibration is based on the time it takes to calibrate an electronic odometer – not a mechanical odometer. Perhaps in rallies where mechanical odometers are anticipated, an odometer calibration run could be run prior to the start of the timed portion of the rally. This would be more competitor friendly. This approach was used in the classic rally in Germany that I recently competed in, the Baden Classic. At that rally, a calibration run was available for all competitiors the day before the formal rally, therefore all cars could have a fully calibrated odometer prior to the start of the timed portion of the rally.
I will post at a later date on my tests for this device, especially when used along with the Kanto Seiki odometer.