One of the great things about going to a rally (or Tech Days or MeetUps or meetings) is comparing gadgets ("farkles") and learning about new things.
One thing that came up at the rally was a discussion/demo of an after-market TPMS if your bike didn't come with one. Robert B talked about his TPMS he installed on his sidecar rig. Here is a link to the company he used:
my-fobo.com
Jerry
"I ride because it frees my mind from the tyranny of petty things."