Modern Vespa

I had just picked up a rear new tire from the shop and 15mins later while I was still out and about my TPMS gave me a warning that my rear pressure was low.

Here's what I found when I got home after a few stops at service stations along the way to get some air ...

EDIT: crosslinks TPMS Tire Pressure Monitoring System and TPMS measurements

Does the GTS have TPMS built in, or have you got an aftermarket system?

Eek.

Not built-in (yet): you can buy TPMS valve caps which work with an app on your phone to keep tabs on tire pressure in real-time. Even better, if you happen to own a GTS SuperTech, and use steelbytes' Vespa Snoop app in place of Vespa's own, among other benefits is an in-built TPMS monitor to give you an even more-convenient heads-up.

Now, my burning question: what the eff happened to cause that puncture?

I carry a couple bottles of a sealer called Ride-On with me. On the two occasions where I wound up with a punctured tubeless tire during the past 20 years, I put that in, reinflated the tire (I also carry a small 12V compressor) and was on my way. I think, as best I can remember, I've only had three flats with tubeless tires on bikes in my life, compared to a couple dozen with tube type tires, which required tow trucks and huge $$$.

A screw-on TPMS Bluetooth sensor adds a lot of levered weight to the end of the fill valve, causing it to wobble, weakening it over time, and possible causing the sensor to smash against the frame as it rotates, especially in the rear. Really not recommended.

You can buy internal Bluetooth TPMS sensors. They do work but they make the tire somewhat harder to install/remove.

as Juan said internal are better. I got cheap internal ones from AliExpress and use my app to monitor them.

you can of course also get ones with a unit that you attach to your handle bars (or dashboard if in a car) instead of using an app

edit: added crosslinks to my previous posts on the topic in the top of this thread

TMPS was not an option on my MC designed the early 90s so I had now way of knowing if a tire was going flat, especially while underway. So I purchased a FOBO 2 Bluetooth TMPS and have been using it for about 2 years. I've found it accurate and easy to use.


You replace your traditional stem cap with the FOBO 2 stem caps then launch the FOBO app on your phone (an iPhone in my case). It displays current pressure, target pressure and temperature. When the pressure falls below the target temperature threshold, the screen flashes and an alarm sounds in my AirPods Pro II that I wear when I'm underway. I routinely ride my bike at 70+ mph and haven't had any problems. The caps are quite light, really not much heaver than a metal stem cap. While underway, the centrifugal force pushes the cap towards the stem so there's not pressure trying to rip the stem out of the wheel. It is a bit pricy ($92) but I find it gives me great peace of mind while riding. It is simple and fast to check tire pressure before every ride without having to rotate the tires to get the stem into measuring position, remove tire caps, get out the tire pressure gauge, make the measurement and replace the caps. I've replaced the standard button battery in each cap after about 16 months. The app provides a low battery warning in plenty of time to get new batteries (I think mine showed low battery for 2-4 weeks before I finally replaced them). There's a (typical sappy) video on the Amazon page showing its operation. I recommend the FOBO II and would put them on any bike I had without TMPS.

I specifically chose not to use a T-valve on the stem. My tires hold air well and I rarely have to top them up and when I do, my pump has a reasonably accurate pressure gauge. Also, the front wheel really doesn't have room for a T-valve because the brake disks are so large. I usually overfill a bit and then bleed off the excess by loosening the cap. This takes a bit of finesse but easy once you get the hang of it


Miguel

iirc I've had 4 in the last several years on GTSs ...

think I'm gonna take the opportunity to test my repair kit today. sticky string plus tiny hand pump (have been thinking of small 12v pump). As long as it will hold enough air for a couple of hours then it would get me out of pretty much any trouble I'll ever get in. Plus it'll let me do the grocery shopping today

have seen people such as Greasy complain about the slime style sealants ...

Is it true that these should never be used on rubber valve stems?

O.S.[/b]

debatable.
more by me on the topic in TPMS Tire Pressure Monitoring System and TPMS measurements
and somebody else's TPMS
and Valve stem problems.

quick surf for a tutorial before testing my kit (although I already believed i knew how to use it) gave me this video by Ryan

This Tire Plug Can Kill You – How to Best Fix a Flat

2023 GTS already has a prepared icon in the display (Classic, Super & SuperSport) for TPMS, however, no sensors are installed...

don't get too optimistic ..
https://modernvespa.com/forum/post2187527#2187527

mind you, piaggio do for the moto guzzi
https://www.af1racing.com/AF1-2D000687-OEM-Moto-Guzzi-Tire-Pressure-Monitor-Set---AF1-2D000687


edit: this is made by Whetron Electronics (Suzhou) Co.,Ltd.
https://manuals.plus/m/f090435c1a5f3e9180717f2ad5bfe2aca52c37fd7deeed1875a3c421a7c06205_optim.pdf


(gotta luv google sometimes)

...Huh.
My rear Bonnie tire (scorpion trail II) last year ended up with 2 mushroom plugs before it even had 4-digit mileage. I ended up with 11k miles on a twice-plugged tire that I was NOT gentle on: interstate, mountain twisties, gravel forest roads, back highway, urban traffic, etc. They didn't budge or leak at all.

After that video, I might have to switch back to rope, at least for dualsport/ADV traveling...drat. The mushroom plugs don't require the brute force that rope needs to put in. The "self-sealing" part of the rope's test was interesting. I didn't know that!

Oh monitoring is so 2022.

Get with the times. Auto adjustment is where we are at in 2023.

https://road.cc/content/tech-news/dsm-use-tyre-pressure-adjustment-hubs-paris-roubaix-291873?amp

So I used my kit and all good. Yes I did use that tiny pump - took 15mins of pumping.

After waiting an hour and checking pressure again I did trip to the shops with a 15km detour. So a couple of power starts at the lights, speed humps, manhole covers, dropping off kerbs, some nice twisties with a couple of hairpins, grandma driving at 15kph in a 40 zone, idiot doing a u-turn in front of me causing pretty heavy braking, etc. ie, a typical trip to the shops (I usually do that detour as the hairpins are so fun).

Test caused increase of temp from 23C (ambient) to 45C resulting in pressure increasing from 27psi* up to 31psi. Worked a treat.

Nice to have confidence in my kit (but ain't gonna go on the freeway or do country riding until I replace the tire)


* 27 is a bit lower than usual but I'd had enough of the tiny pump and was too lazy to get the normal tire inflator

Thank you ....after reading that even the manufacturer recommends against the installation on rubber valve stems - I'll not use them.
O.S.

Why not put it in the tires before getting flats?

I've had two flats in 3 years on my GTS. I've detected both by noticing traction control engaging more often than usual.

The first one required a tow truck; I was on the other side of the bridge and the tire wouldn't hold air.

The second one I rode to a Costco and rope patched in the garage with the help of their tire inflator machines.

If you're insured by State Farm in the US, their comprehensive plan covers towing and labor for emergency roadside. You get a new tire for just the cost of the rubber. It can actually be to your financial benefit to get a flat if your tire has some miles on it.

Good thinking....I had them on a Vstrom and the rear caused the stem to fail while I was several hundred miles up the Alaskan Highway. It was a Sunday but two Goldwing guys took my tire into the nearest town and got a guy to open up and install a new stem! Cost me $20..... Never used them again!