User manual

GPX Pro 44

NOTE: When you are going below about 3mph (5kph), the gear

will be reported as "N" when utilizing rpm/speed ratio to report

gear.

There is one particular advantage to using the rpm/speed ratio for capturing gears (even if you

have a gear sensor), if you are already capturing RPM: using this method does not "use up" an

analog input.

Using different gear ratios (cars) or sprocket ratios (motorcycles)

If you sometimes (or often!) change your transmission ratios, the GPX can automatically account

for that change and still report correct gear changes.

We'll use a car as an example first. Let's assume you have calibrated the gears, and you car's gear

ratio is 3.00. Go to the menu Set/change axle ratio, Set axle ratio at initial calibration, and enter

3.00. You may then use the GPX and as long as you do not change your axle ratio, the gear data

will be properly recorded. Now let's assume you make a modification to your vehicle, and the

new ratio is 3.63.

You do not need to g o throug h the length gear calibration process

. Merely go to

the menu item Set/change axle ratio, Enter current axle ratio, and enter 3.63. You're good to go.

For a motorcycle, the process is identical, except you enter front and rear sprockets instead of

axle ratios. For example, you might enter 16-43 (front sprocket 16 teeth, rear sprocket 43 teeth)

as your initial axle ratio (assuming you calibrated all your gears with that 16-43 combination);

then, when you change your sprockets, merely enter the current sprocket ratio (e.g, 15-44).