What's so great about presta valves?

[craigwend]

The main problem with these Schrodinger's valves is you don't know if the air is alive or dead until you let it out...

 

[Dadam]

So Prestas are designed to be farking fragile and Schraders are designed to leak in use at typical-for-bikes low pressures and need pumping up too often? It's almost like they were inflicted on cycling by motorists.

Umm... car tyres tend to be around 30-40psi, a similar range to MTBs. If memory serves my old 70s Cortina was 26psi, my current 3 series is 37 (rears when fully laden). So very similar; if anything the average bike tyre is higher pressure. I run the 35s on my hybrid at 60psi with schraders.

So far on this thread we've had assertions that schraders aren't designed for the high pressures of bike tyres and, simultaneously that they leak at the low pressures of bike tyres. You couldn't make this up.

 

[Dogtrousers]

Out of interest, does anybody run tubeless with Schrader valves? I mean on a bicycle rather than automotive use?

Dunno, but I was repairing a friend's wheelbarrow years ago and I took the schrader valve core out and filled the tube with slimey gunky sealanty stuff (sorry for the technical term) and replaced the core and it seemed to work. (It probably immediately went flat as soon as I left)

 

[Ian H]

Out of interest, does anybody run tubeless with Schrader valves? I mean on a bicycle rather than automotive use?

Tubeless Schraders, at least the ones for cars, are very much more bulky than tubeless prestas.

 

[Dogtrousers]

So far on this thread we've had assertions that schraders aren't designed for the high pressures of bike tyres and, simultaneously that they leak at the low pressures of bike tyres. You couldn't make this up.

We've also had claims that schraders work fine on aeroplanes at bonkers high pressures. I'm willing to bet that the valves on a 747 wheel that cost a bazillion dollars each may possibly look from a distance like the Schrader valve on an Apollo MTB but close up it will be a very different animal indeed. And each one will cost more than several crate loads of Apollo MTBs.

And we also have claims that Prestas are "fragile". I asked if anyone had ever had a Presta break on them and all I got was that the sticky up bit might get bent. Well yeah, that can happen. But the valve still works fine, but looks a bit wonky. That's the opposite of fragile. It's robust.

However it is true the Woods valves are often a vector for syphilis. That's definitely true, and I didn't just make it up.

 

[tyred]

Definitely Anglia on Tower Street King's Lynn stock them. Possibly other non-chain shops here do, but I think Motor World was the last chain to and they've been gone a few years.


So Prestas are designed to be farking fragile and Schraders are designed to leak in use at typical-for-bikes low pressures and need pumping up too often? It's almost like they were inflicted on cycling by motorists. The only reason to use Presta is if your rims are too narrow for anything better. The only reasons to use Schrader are if you run out of Woods tubes, or you're some sort of masochist, or you've lost the adapter from your puncture kit and only have a car tyre pump available.

Funnily enough, I've never broken a Presta valve or had a Schrader valve leak (on a bike. Did have one leak on a tractor tyre.) I must be doing something wrong!

I have had Woods valves fail when the rubber tube split.

 

[Dadam]

We've also had claims that schraders work fine on aeroplanes at bonkers high pressures. I'm willing to bet that the valves on a 747 wheel that cost a bazillion dollars each may possibly look from a distance like the Schrader valve on an Apollo MTB but close up it will be a very different animal indeed. And each one will cost more than several crate loads of Apollo MTBs.

Well they do work fine at bonkers high pressures. That's a fact. There was an implication that the basic design wasn't designed to cope with high pressures. Nobody was suggesting that Boeing buy their valves in bulk from Wiggle or Halfords or Aliexpress.

I tried to find some kind of data sheet for tyre schrader valves or a standard for the max pressure but the best I could do were a couple of links like this: https://simplybearings.co.uk/shop/p...O3xIh50fEPwtzuu5XUrxSjdgvcnVsmAMaAvHGEALw_wcB. A pack of Schrader cores rated to 200 psi... £5.48 for 4. So probably not aerospace spec but I imagine would probably do quite well for bicycles.

 

[Dadam]

surely this opening question is only something asked by knuckle dragging neanderthals who have only ridden MTB and hybrids all their life and have now see the sunlight of the road /gravel bike world?

I missed this one, must have zoned out when people were arguing about tongues and suction!

Yup that's me! 🦍

 

[Dadam]

Oh yes there's also the gem about increased drag with schraders!

 

[classic33]

I use standard BMX tubes, Schrader valves at 110+ PSI. No problems with keeping the air in.

 

[ChrisEyles]

Schraeder valves on MTB rear shocks hold 180+ psi no problem, and hold this pressure for months despite containing only a very small volume compared to a tyre.

Only reason to use presta IMO is if your rims are too skinny to fit schraeder valve sized holes in.

They are undoubtedly more fragile than schraeder valves and offer no advantages I can see.

Having said that I'd happily run a presta tube of that's what I had in the garage.

 

[Dogtrousers]

Schraeder valves on MTB rear shocks hold 180+ psi no problem, and hold this pressure for months despite containing only a very small volume compared to a tyre.

Only reason to use presta IMO is if your rims are too skinny to fit schraeder valve sized holes in.

They are undoubtedly more fragile than schraeder valves and offer no advantages I can see.

Having said that I'd happily run a presta tube of that's what I had in the garage.

How often have you got your bike out and found that the valves have unexpectedly shattered due to their extreme fragility?

Valves are valves. Meh.

 

[HLaB]

How often have you got your bike out and found that the valves have unexpectedly shattered due to their extreme fragility?

Valves are valves. Meh.

I am not sure if it was from a fall on Sunday (although it wasn't enough to even mark my bibs or cause any bruising) or from using a CO2 cannister just after 😐

 

[Dogtrousers]

I am not sure if it was from a fall on Sunday (although it wasn't enough to even mark my bibs or cause any bruising) or from using a CO2 cannister just after 😐

Does it keep air in?

 

[HLaB]

Does it keep air in?

It does now but after I replaced the core.