speedo gear Q

You should not have to change gears when you change a speedometer. The different spedometers are supposed to read the same cable rpm as the same speed.

Now that I've said that... I know that some folks have had problems with putting in a different speedo. I think they may have gotten an old speedo that has had a new face put on it, and caibrated for the new face. This would require a new speedo gear to compensate for the different calibration.