Tire pressure monitors have been available for cars for a long time and have proven to be a lifesaver. Since 2007 it has been mandatory on all new cars or trucks in the USA. It’s only in recent years that they have started to get fitted on higher-end motorcycles and are available as aftermarket kits.
The Tire Pressure Monitoring System (TPMS) is an electronic system for your motorcycle that monitors the tire air pressure and alerts the rider when it detects a pre-set drop (15%) in pressure or increase (35%) due to temperature. Sensors on each tire, periodically wirelessly transmit the pressure status of the tires to a monitor either integrated into the bike dashboard or externally mounted.
What does a TMPS monitor look like?
TPMS monitors come in two different varieties.
Integrated (Internal sensors):
The pressure display is normally part of the dash and the sensor mounts inside the tire on the rim.
After Market (External sensors):
The pressure display is normally external and the sensor mounts outside on the tire valve stem.
What are TPMS monitors like to actually use?
I have friends that have aftermarket systems and I hear mixed reviews. Like anything, it depends on how you ride, do you like gadgets, system specs etc. As we know, opinions are like “bottom holes”, everybody has one.
On my KTM 1190R, I had a TPMS monitor fitted as standard.
From experience, the system was a blessing and a nightmare.
Blessing: Gives you some peace of mind and accuracy (+/- 5%) when it comes to tire pressures and detecting a slow leak.
Nightmare: When you end up checking the pressures every 5 mins while riding. If you suffer from OCD, do not get a TPMS monitor. LOL!
Pairing the sensors with the receiver on start-up can be an issue. If the sensor is removed for some reason at a tire change, replaced or the rim gets knocked hard close to the sensor, you may need to get the dealer to reset or have the TPMS monitor “re-learn” the sensors.
How accurate are TPMS monitors?
Some systems claim to have an accuracy of +/- 1%, but in my experience, it’s closer to +/- 5%. You will also find systems that will display tire air temperatures with similar accuracy claims. I have never used a system showing tire air temperature, so no idea if the accuracy claims are true.
Can I use “Slime” or similar tire sealant aerosols?
Some manufactures of TPMS sensors that are mounted internally on the rim, advise against using tire inflation or sealant aerosols, as the glue can gum up the sensor and stop it from working until it is cleaned out. That said, Slime on their website clearly state they are TPMS safe for manufactures of sensors. YMMV, so use it at your own risk.
More info from Slime: https://www.slime.com/us/blog/what-does-it-mean-to-be-tire-sensor-safe.php
Can valve-mounted TPMS sensors be used with rubber or 90° valve stems?
In short, yes, but double-check, as some systems advise against mounting their monitors on rubber valve stems due to the added weight, harmonic vibration, causing the valve stems to crack. Also, rubber valve stems can or deteriorate over time in some climates.
How long do the sensor batteries last?
Most TPMS sensors use small lithium button batteries, like the type you find in watches.
Bikes with internal sensors that are mounted on the rim and integrated as part of the bike electronics in my experience last 3-5yrs before needing to be replaced. I owned a KTM 1190R for 3 years that had an integrated TPMS monitor, and I never needed to change the sensor batteries in that 3-year period.
Note: Some manufactures use TPMS sensors that are non-replaceable on some models. Honda and Kawasaki are two manufactures that come to mind. It might be worth asking when you buy a bike with a TPMS monitor, are the sensor batteries replaceable, or you might be in for a nasty shock a few years down the line.
Can they be damaged by changing a tire?
Yes, they can. If you are using tire irons, make sure you start opposite to the location of the valve stem and sensor, to avoid damaging the sensor. If a mechanic is changing your tires, let them know you have TPMS sensors fitted.
If you ever need a replacement sensor, this is not a bad place to start. They have organized eBay listings: http://tire-pressure-sensor.com/
Are TPMS monitors waterproof?
I have never seen an integrated TPMS monitor that is not waterproof and dustproof.
Aftermarket systems are a different story, especially the cheaper systems you see on sites like AliExpress etc. Make sure you double-check and read the reviews before buying!
Can you buy aftermarket TPMS monitors?
Many 3rd party companies offer add-on TPMS systems.
They range from US$25-150 and everything in-between. Many are actually the same systems, but re-branded. You will find no end of options on sites like AliExpress, Amazon etc, so do your due diligence and find what works for you.
When you buy, make sure the system is for a motorcycle. I know that sounds obvious, but I have seen people make this mistake.
Below are a couple of the better-known TPMS monitors on the market for reference.