I have the Doran Manufacturing TPMS (~$200). It's a full featured system for motorcycles, trikes and cars. It runs on the bikes 12V system so no batteries to change in the head unit. It comes with thread-on sensors for the valve stems but it also comes with special, steel, valve stems that allow you to mount the TPMS sensors inside the tire. I didn't use their stems so mine are mounted on the outside. My complaint is that the TPMS sensors make for a leak path when they are screwed on the outside of the tire. And, since I use balancing beads, I lose air whenever I remove the sensors to measure or add air. I'm going to convert my system to use their valve stems and put the sensors inside the tire when I get motivated. My other complaint is that when the bike is turned off current tire pressure indication is lost. Since the TPMS sensors only transmit once every few minutes, to conserve battery life, it may take 5 minutes before they have reported in. Don't worry too much about this because if there is a sudden loss of air pressure they transmit immediately and the head unit goes into alarm. But is inconvenient when heading out of the garage and you can't get an immediate update to know if you should top-off before leaving home.
The TireGard handlebar mounted system looks interesting and the head unit is battery powered. So, I hope others will chime in with their experiences using it other products.
I've got the TireGuard/Big Bike Things TPMS on both my bikes, although not with the handlebar mounted receiver. My receiver can be used as a key fob.
The system consists of a programmable receiver and a front and rear transmitter. The transmitters take the place of the valve stem caps. They are a little large-looking, but do not weigh much.
The system monitors tire pressure and internal tire temperature as you ride. Like BonS' units, it transmits every few minutes. The system stays active for about 20 minutes after the bike is parked, and the last transmitted data is saved. When you turn the system back on the next time you use the bike, it takes a 1 psi change from the last recorded pressure for updates to start. These are battery saving features.
High and low pressure, and high and low temperature alarm levels can be set. It gives an audible alarm and the display flashes when a threshold is crossed.
Mine consistently read 1 to 1.5 psi lower than what I measure using a digital pressure guage. This is consistent bike-to-bike, so it's either by design in the TPMS, or my digital guage is off. It's no big deal to me, since what I'm interested in is relative changes, especially dramatic ones.
They work fine with 90° valve stems. I would recommend all metal stems because the (even slight) extra bulk of the transmitters will add to the forces working against the base of the valve stem. I would NEVER use them with OEM stems if the plastic support piece for the OEM stems were not also in place. They would work very well with stubby straight stems.
They also work fine if you are running Ride-On balancing and sealing compound in your tires, which is not true with all internally mounted TPMS systems.
I'm happy enough with the product that I would buy them again.
