They can also hold higher pressures, which makes them a must for track cycling where tyre pressures typically exceed 120psi.

That’s balls though, isnt it? Rear shocks can take 250psi or more and they take much more of a hammering than track tyres. (That’s not directed at you, it’s directed at that nonsense spouted on Cycling News.) I dunno. Meh. I’m arguing on STW, do I win £5?

I’ve never bent one and never had a core unscrew. Do I get a Presta Valve badge to sew on my jersey?

I have had one which my pumps wouldn’t screw onto. Seemed to be a malformed thread.

Sods law i read this thread yesterday and i thought ive never snapped a presta valve and i have 5 bikes fitted with them and have been using them for 30+ years

Went to pump up my road bike tyre today and somehow managed to snap the whole tubeless valve about 20mm up from the lock ring, on the bright side the actual presta valve is intact!

New tubeless valves ordered from Wiggle on my +account

.They can also hold higher pressures, which makes them a must for track cycling where tyre pressures typically exceed 120psi

Schrader will take 120psi, 9 bar is high-end for a truck, 130.5psi. 8 bar is a good average, 116psi. Haven’t seen a truck with Presta valves yet
Presta means “fast” which is why you need them on the track. A track rim with an 80mm Schrader valve might have an imbalance 🙂

I moved to presta when I had velocity deep v 90s rims

There were no 75-90mm schareders availible and no. Valve extensions availible.

Then when xc racing I used c02 cans and at the time there were no Schrader adaptors for those.

Just standardised with it on all my bikes due to there being literally no downside to doing so and ensured I didn’t have to fanny around with my pump converting it in the dark and cold …..I also mitigated against cheap shit pumps by not buying a cheap shit pumps.

I like presta simply because it has a locking to stop the valve being pushed into the wheel when I’m pushing on the pump

You can get schraeder valves with lock rings as well, they are less common but definitely handy (as long as you don’t use them as a fixture to swing your pump off of).

As I said before, Schraeder allow higher flow (never had an issue seating tyres even on my basket case 729 with the bent lip) and don’t clog as easily.

I don’t buy the less permeable argument either. Shocks, forks, gas rams and air cylinders all have schraeder cores. I have a modified air rifle with an 800psi airsoft tank that hasn’t dropped pressure since it was last used a few years ago.

That test (if there was an actual test and not just uninformed “common knowledge” nonsense) was probably carried out comparing decent presta tubes vs whatever cheap crap schraeder tube was lying about.

Shocks, forks, gas rams and air cylinders all have schraeder cores.

They are used in a lot of applications. For high-pressure critical applications, much higher quality cores are used. Those aren’t necessary for tyres running at 30 psi.

So if I’m running tubeless with sealant and I put schrader converters onto my prestas I could leave them on and use my JoeBlow pump with dual inflation head. No need to take them off other than any sealant maintenance? Is there a downside to that?

Edit: running at less than 30 psi

You want a push and lock pump. Any hand pump, if you are ham fisted, get one with a mini hose, it removes stress on the valve.

They are used in a lot of applications. For high-pressure critical applications, much higher quality cores are used. Those aren’t necessary for tyres running at 30 psi.

True but their quality is determined by their ability to hold pressure. Why would the two be any different assuming the valve seat is clean and isn’t distorted from over tightening? The design principle is essentially the same, it’s a brass valve held on its seat by the pressure behind it any additional tightening force (in the case of Presta) is hardening the valve face onto its seat which, over time, is actually more likely to make it leak.

That aside, there are probably more factors that would cause a leak before the valve can be blamed.