Has anyone tried the TireGard wireless TPMS? Expensive, but it looks like a good idea - just wonder if it will effect the wheel balance?
Yes, I would expect that the sensor hanging on the valve stem would affect balance.
I did some reading on that TireGard system some time ago, and afer doing so my main reaction was "why would I spend $200 just to avoid bending over to check my tire pressures?". The system isn't set up to be a full time monitor with a display on the bars; the display is made to fit in your pocket. Any alarm it sounds would most likely be drowned out by the mechanical and exhaust sounds, as well as being muffled by your pocket of course.
IMHO, it would be much wiser to spend perhaps 20% of that price on a quality tire pressure gauge, and then train yourself to check your tire pressures at least once a week prior to the first ride of the day (cold). One advantage of doing it the old fashioned way is that getting down and dirty will force you to inspect your tires, possibly alerting you to abnormal tread wear, or perhaps a nail stuck in the tire that could fly out and cause a sudden rapid deflation, or any other obvious problem. A monitor system won't do any of that for you.
As for the subject of this thread, I've found over the years that the vehicle manufacturer's specs tend to reflect the minimum safe pressures, while the sidewall pressure is the maximum pressure. The ideal pressure will be somewhere in between, depending on whether you're looking for maximum tire life, best handling, or best ride. I personally run 38 front and rear, versus Harley's recommendation of 36 front and rear, and I bump the rear up to 40 when riding two-up. I get 11,000 to 12,000 miles on a D402 rear tire, changing well before reaching the 1/32" minimum tread depth (usually around 3/32").
Jerry
As a side note, this is one of those times of year when ambient temps are rapidly changing for many of us. Tire pressures change roughly 1 psi per 10 degree change in temp, so it's wise to check tire pressures more often until daily temps stabilize. While you've got the gauge out, check all your other vehicles as well. That tire monitoring system on your new car or truck that just meets Federal regs won't tell you diddly until your pressure is 25 to 30% below spec.