Andy makes a good point.

I think that there are two concerns that need to be carefully investigated before installing an aftermarket TPMS on a motorcycle:

1) If the device is a 'cap' that fits onto the end of the valve stem, then you will need to replace existing plastic or rubber valve stems with metal valve stems. This is because the centrifugal force of the rotating wheel causes the 'cap', no matter how small and light it may appear, to exert a force on the valve stem. Over time, a plastic or rubber valve stem may not be able to handle the repeated deformation cycles imposed by this force.

This might present an insurmountable problem for folks who run tires with tubes in them.

2) You need to be a critical consumer, and remember that you get what you pay for. The little Garmin valve caps that I use cost about US $75 each, and that's just for the sensor - there is also the additional cost of a GPS navigator that has TPMS capability if you do not already own one.

There are a lot of TPMS products coming out of China. Many of these are made by companies without an established reputation. I hate to paint a country with a broad brush, but, would you buy a helmet with a "Made in China" label on it?

Do the research, read the various reviews, search the forums and see what the experience of others has been before you buy an aftermarket TPMS.

Michael