pressure gauge for schrader, presta, & woods valves

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Jdsk
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Re: pressure gauge for schrader, presta, & woods valves

Post by Jdsk »

mjr wrote: 26 Oct 2021, 8:43amOnly a pump gauge will read Woods, due to the design.
Mick F wrote: 27 Oct 2021, 9:41am My track pump - and the previous one - has a pressure gauge. The connector will go on all valve types.
Press the plunger to equalise the pressure and the gauge will tell you the tyre pressure.
Sheldon Brown on the types of Wood valves and their differences:
https://www.sheldonbrown.com/inner-tubes.html

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Wilhelmus
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Re: pressure gauge for schrader, presta, & woods valves

Post by Wilhelmus »

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Last edited by Wilhelmus on 25 Nov 2021, 2:17pm, edited 1 time in total.
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Re: pressure gauge for schrader, presta, & woods valves

Post by Bmblbzzz »

The, for lack of a better word, mass market puncture kits sold by eg Lidl and Aldi usually contain a short length of rubber tube nowadays.
MikeF
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Re: pressure gauge for schrader, presta, & woods valves

Post by MikeF »

Mick F wrote: 27 Oct 2021, 9:41am My track pump - and the previous one - has a pressure gauge. The connector will go on all valve types.
Press the plunger to equalise the pressure and the gauge will tell you the tyre pressure.
What plunger? The air valve on a woods valve is at the base of it, and if it's rubber tubing it won't be opened by pressing a plunger. I've not checked if the valve on the more modern ones can be reached from the top.

I've just checked Sheldon Brown. A pressure reading is possible with many Woods valves only while pumping.
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Mick F
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Re: pressure gauge for schrader, presta, & woods valves

Post by Mick F »

Yes, like I said.
Press the plunger and the pressure will equalise and the pressure gauge will show the pressure in the whole system.

By "plunger" I mean the pump plunger with the handle.
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Re: pressure gauge for schrader, presta, & woods valves

Post by Mick F »

PS:
It works the same way with Presta too, and the pump connector only depresses the Presta valve when air is being pumped.
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Re: pressure gauge for schrader, presta, & woods valves

Post by MikeF »

OK. I agree that works with Presta and Schrader because the "plunger" can press on the the valve, but in the case of Wood's valves there may not be a mechanical valve, eg rubber tubing or on the ones I've seen the valve is near the bottom and the "plunger" wouldn't reach it.
Maybe with some new ones the valve extends to near the top - I don't know.
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RickH
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Re: pressure gauge for schrader, presta, & woods valves

Post by RickH »

MikeF wrote: 28 Oct 2021, 9:40am OK. I agree that works with Presta and Schrader because the "plunger" can press on the the valve, but in the case of Wood's valves there may not be a mechanical valve, eg rubber tubing or on the ones I've seen the valve is near the bottom and the "plunger" wouldn't reach it.
Maybe with some new ones the valve extends to near the top - I don't know.
I think there is some misunderstanding. When you use a track pump (& most, if not all, hand pumps) with presta (& woods) valves nothing physically presses the valve open (unlike shraeder valves). Operating the pump until some air goes into the tube will equalise* the pressure in the tube & pump & the pressure gauge on the pump will indicate the same pressure as is inside the tube.

(* OK the pressure in the tube will have increased very slightly as you pump but the pressure will still be equal on both sides of the valve, unless you have a leaky pump.)
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Mick F
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Re: pressure gauge for schrader, presta, & woods valves

Post by Mick F »

Yep.
That's what I said, or at least meant.
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Re: pressure gauge for schrader, presta, & woods valves

Post by Mike Sales »

It is interesting to watch the gauge as you pump.
It goes to a rather higher pressure than the air in the tyre as you pressurise the air in the pump, and then drops steadily down to the tyre pressure before pausing at tyre pressure. It may then slowly drop as the pump system leaks.
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Re: pressure gauge for schrader, presta, & woods valves

Post by MikeF »

RickH wrote: 28 Oct 2021, 10:22pm
MikeF wrote: 28 Oct 2021, 9:40am OK. I agree that works with Presta and Schrader because the "plunger" can press on the the valve, but in the case of Wood's valves there may not be a mechanical valve, eg rubber tubing or on the ones I've seen the valve is near the bottom and the "plunger" wouldn't reach it.
Maybe with some new ones the valve extends to near the top - I don't know.
I think there is some misunderstanding. When you use a track pump (& most, if not all, hand pumps) with presta (& woods) valves nothing physically presses the valve open (unlike shraeder valves). Operating the pump until some air goes into the tube will equalise* the pressure in the tube & pump & the pressure gauge on the pump will indicate the same pressure as is inside the tube.

(* OK the pressure in the tube will have increased very slightly as you pump but the pressure will still be equal on both sides of the valve, unless you have a leaky pump.)
Except the pumps I have, have a "plunger" that will press on both Schrader and Presta valves. It's operated by a lever.
I have a gauge on the track pump and when connected, the gauge will give a reading because air has been allowed to be realeased from the tube and reach it. If the valve hadn't been pressed the gauge would not give a reading. There isn't a need to operate the pump to obtain a reading.
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mjr
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Re: pressure gauge for schrader, presta, & woods valves

Post by mjr »

MikeF wrote: 29 Oct 2021, 1:02pmExcept the pumps I have, have a "plunger" that will press on both Schrader and Presta valves. It's operated by a lever.
I would call that a pin. We have previously discovered during discussions that some pump heads have it but not all do.
I have a gauge on the track pump and when connected, the gauge will give a reading because air has been allowed to be realeased from the tube and reach it. If the valve hadn't been pressed the gauge would not give a reading. There isn't a need to operate the pump to obtain a reading.
You would need to operate the pump to obtain a reading for a Woods-valved tube, as there is nothing for the pin to depress. This small drawback is worth it for the great benefit of never having a failed valve core deflate your tube IMO... and I find that Woods-valved tubes hold pressure longer, but I think people suggested that may be because the remaining manufacturers are higher-end than the widespread cheap Schrader junk tubes, although I generally buy branded tubes of all valve types.
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Re: pressure gauge for schrader, presta, & woods valves

Post by ANTONISH »

Wilhelmus wrote: 26 Oct 2021, 9:47am The old rule of thumb, when pumping up a bike tyre, was to stop two strokes of the pump before it bursts. Seriously, though, the great advantage of the old-fashioned cylindrical hand pump, for which mounting points were usually provided on the frame, is that it gives the user feedback, in the sense that it becomes harder and harder to get any more air in. This, combined with the finger and thumb test, usually proved adequate, even if you were Fausto Coppi or Tullio Campagnolo. With such a pump, it was virtually impossible to over-inflate a tyre.
I rarely use my pressure gauge - I just use my thumb as you describe - maybe a bit softer if its wet - bit harder dry.
On the odd occasion when I check with a gauge the pressure is always within the limits shown on the tyre.
My Zefal frame pump will definitely overinflate any tyre that I use.
Pressure gauges are in any case only accurate within limits.
My thumb tells me if a tyre is OK to ride on - the actual pressure is academic,
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Re: pressure gauge for schrader, presta, & woods valves

Post by ANTONISH »

What plunger? The air valve on a woods valve is at the base of it, and if it's rubber tubing it won't be opened by pressing a plunger. I've not checked if the valve on the more modern ones can be reached from the top.

I've just checked Sheldon Brown. A pressure reading is possible with many Woods valves only while pumping.
[/quote][/quote]
In the fifties a replacement for the Woods valve was produced which had a plunger type seal- I bought some.
They are in the picture up thread.
Of course you are right that you can't get a pressure reading because the valve isn't open.
gxaustin
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Re: pressure gauge for schrader, presta, & woods valves

Post by gxaustin »

What is the advantage(s) of the Woods valve? I had them as a kid, before moving on to Schrader, and then Presta.
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