Presta and Schraeder Valves



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Just zis Guy, you know? wrote:
> I have superficially similar tyres and tubes fitted with both Presta and Schrader valves. The
> Prestas all hold pressure better. Maybe Tony is right and the Michelin Airstop tube with Prestas
> is better made than the *identically priced* tube with Schraders.

You may well be right for all I know that Schraders leak but to be fairly certain, you must test
with identical tyres and intentical tubes (except for valves). Different sizes/versions of tubes can
have the same price. Small differences in tyres and tubes have made astonishing differences to air
holding in my experience.

~PB
 
On Fri, 30 Jan 2004 10:45:01 -0000, "Dave Larrington"
<[email protected]> wrote:

:)pmailkeey wrote: ) )> Got prestas on your car too ? Mine on the car match the bike. I like )>
:standards. ) )No. But since a car tyre pump is of limited use for inflating high-pressure
:)bicycle tyres,

Maybe the cheap ones.
--
Comm again, Mike.
 
On Fri, 30 Jan 2004 12:40:59 -0000, "Dave Larrington"
<[email protected]> wrote:

:)Just zis Guy, you know? wrote: ) )> If it please the Court, I regularly use my track pump to
:inflate the )> tyres of my mobile death greenhouse. )> )> It has a dual head, Schrader and Presta,
:as does my Topeak Road Morph. ) )While this may be the case, Your Honour, motorcar tyres contain
:lots of air )at comparatively low pressures, while road bicycle tyres contain little air, )at high
:pressure. Track pumps, as the name suggests,

..it's used to pump up tracks ?

--
Comm again, Mike.
 
On Fri, 30 Jan 2004 10:47:42 -0000, "Dave Larrington"
<[email protected]> wrote:

:)Public Biggs Announcement. ) )Mr. Biggs has gone mad. ) )First we read that he fries patches, now
:he wants to teach his wheels to )swim...

Wonder what he uses on his ducks ?

:) )Normal Pete Biggs will be resumed as soon as possible. ) )That is all. ) )-- ) )The Sanitory
:Inspector )Friern Barnet ) )

--
Comm again, Mike.
 
On Fri, 30 Jan 2004 23:31:29 -0000, "Danny Colyer"
<[email protected]> wrote:

:)"pmailkeey" wrote: )> Some time ago, I checked the web on this and Schrader was the more )>
:popular spelling. And that's how it's spelled on the box a spare tube )> is in ! ) )That reminds me
:that I've got a couple of said tubes downstairs (not for )any of my machines, you understand, but
:bought as spares in case of )punctures when riding with the neighbours' kids in the summer). The
:)boxes that these Specialized tubes came in have "Schraeder Valve Tube" )written on the sides. )
:)So nyaa :p ) )(Also, when spellchecking this post, the Microsoft spellchecker )suggested
:replacing "Schraeder" with "Schrader". Which suggests to me )that "Schraeder" is a better
:spelling). )

When is a light bulb a lamp? Well, Mr Edison referred to "lamps" in his patent - although I thought
"light bulb" cropped up in there somewhere too.

I'd gues the S-valve was patented - and if so, how was the name spelled there ! ?
--
Comm again, Mike.
 
On 30 Jan 2004 11:29:51 -0800, [email protected] (Dave Kahn) wrote:

:)"Just zis Guy, you know?" <[email protected]> wrote in message
:news:<[email protected]>... )> "John Everett"
:<[email protected]> wrote in message )>
:news:[email protected]... )> )> > >An air tank the same volume as a cycle
:tyre? )> )> > As if that makes any difference. Air pressure is air pressure, )> > independent of
:the containment vessel. A valve either leaks or it )> > doesn't. )> )> OK, let's say the valve
:leaks 1cc per hour at 120psi. Pump up a bike tyre )> and an aircraft tyre to 120psi. Leave for ten
:hours. Measure the pressure. )> Think about it. Remember your O level physics. ) )Do you really
:think Schraders leak at higher pressures? I thought the )only disadvantage of using them for high
:pressure applications was )that they were a bit harder to inflate.

Considering the usual attachments for them mechanically open the valve during inflation, there'll be
less air-effort to inflate the tyre than with prestas !
--
Comm again, Mike.
 
pmailkeey wrote:
> When is a light bulb a lamp? Well, Mr Edison referred to "lamps" in his patent - although I
> thought "light bulb" cropped up in there somewhere too.
>
> I'd gues the S-valve was patented - and if so, how was the name spelled there ! ?

Someone mentioned earlier in the thread that the valve was invented by a company called Schrader, in
which case the spelling "Schrader" would certainly be correct. When made by other manufacturers, the
spelling they choose for their own product may also be correct (in much the same way that "disc" is
correct when referring to a CD, because "Compact Disc" is a registered trademark).

Of course, it's also possible that "Schrader" is a registered trademark, in which case a valve made
by a different manufacturer might have to be called by the generic name "schraeder". A bit like hook
and loop fastener isn't supposed to be called velcro unless made by Velcro, elastane isn't supposed
to be called Lycra unless made by DuPont, and Google really don't like people describing searching
the web as "Googling".

You're right, it probably has been patented and it would be interesting to see how it's spelt there.
I suspect that both spellings are probably correct, for one reason or another.

--
Danny Colyer (the UK company has been laughed out of my reply address)
http://www.speedy5.freeserve.co.uk/danny/
"He who dares not offend cannot be honest." - Thomas Paine
 
On Mon, 02 Feb 2004 21:04:33 GMT, [email protected]
(pmailkeey) wrote:

>Considering the usual attachments for them mechanically open the valve during inflation, there'll
>be less air-effort to inflate the tyre than with prestas !

Or there would be if the attachments for Prestas didn't also open the valve.

Guy
===
May contain traces of irony. Contents liable to settle after posting.
http://chapmancentral.demon.co.uk
 
On Mon, 02 Feb 2004 21:04:34 GMT, [email protected]
(pmailkeey) wrote:

>When is a light bulb a lamp?

When it's being accurately described. A lamp is the little glass and brass thing, the thing it fits
into is a lampholder, light fitting, luminaire or possibly electrolier if you're really grand.

>I'd gues the S-valve was patented - and if so, how was the name spelled there ! ?

Schrader.

Guy
===
May contain traces of irony. Contents liable to settle after posting.
http://chapmancentral.demon.co.uk
 
Reply to Just zis Guy, you know?
> >When is a light bulb a lamp?
>
> When it's being accurately described. A lamp is the little glass and brass thing, the thing
> it fits into is a lampholder, light fitting, luminaire or possibly electrolier if you're
> really grand.
>
>

In theatre, where I earn my crust, IIRC the lamp goes into the lampholder on the lamptray, which is
part of the luminaire, which is a posh but commonly-recognised name for a lantern. Calling lanterns
lamps is another example of Thurber's "thing contained for the container".

--
Mark, UK. [Who wonders what overlap - other than me - there is between u.r.c. and
rec.arts.theatre.stagecraft] If you give me six lines written by the most honest man, I will find
something in them to hang him. - Richelieu
 
On Sat, 31 Jan 2004 09:29:09 +0000, "Just zis Guy, you know?"
<[email protected]> wrote:

:) )Looking at the web I found quite a lot of sites describing how to )*stop* them leaking, so that
:does tend to suggest that leaks are not )uncommon.

Was there any indication as to the cause of the leaks ?

An easy anser is to change the valves ! Can you do that with Prestas ? AFAIK, there are unscrewable
ones, but I know some don't. All Schraders do !

:) )Schraders are used in high pressure applications (e.g. aircraft )tyres). One strength of
:Schraders is that you can feed a lot of air )through them very fast.

!!! ? One can indeed remove the whole valve to aid in/deflation rates.
Where large tyres demand greater inflation rates still, the Schrader bodies can be removed leaving
something like a clear 3/8" hole, or possibly bigger.

:)There are a couple of things in this thread which I don't understand: )one is the "standards"
:argument which would , after all, indicate that )we should all standardise on heavy steel bikes

?? But having a transport type independent standard which is quite suited to bicycles seems quite
sensible. IF racing cyclists prefer Prestas for less weight, I don't mind !

:) )Maybe if I cleaned the Schraders really thoroughly they would hold )pressure better - and maybe
:it is rather easier just to use a valve )which doesn't *need* to be cleaned ;-)

I've not seen the same chalk contamination on car valves - so why bike tube manufacturers fill
theirs with dust, I don't know.
--
Comm again, Mike.
 
"pmailkeey" <[email protected]> wrote in message
news:[email protected]...

> Was there any indication as to the cause of the leaks ?

Crud in the valve seat mainly

> An easy anser is to change the valves ! Can you do that with Prestas ? AFAIK, there are
> unscrewable ones, but I know some don't. All Schraders do !

Since I've never had a tube outlast the valve that's not really an issue.

> ?? But having a transport type independent standard which is quite suited to bicycles seems quite
> sensible. IF racing cyclists prefer Prestas for less weight, I don't mind !

You miss the point. Presta is also a standard. Bill Gates would love it if eveybody gave up on every
other type of operating system on the basis that Windows has umpteen percent market share, this is
known in the Mac an Linux worlds as the "40 billion flies can't be wrong" argument...

> I've not seen the same chalk contamination on car valves - so why bike tube manufacturers fill
> theirs with dust, I don't know.

AIUI the dust is there to stop the tubes sticking together when packed. Car tyres are, of
course, tubeless.

--
Guy
===

WARNING: may contain traces of irony. Contents may settle after posting.
http://www.chapmancentral.co.uk
 
On Mon, 2 Feb 2004 22:46:05 -0000, "Danny Colyer"
<[email protected]> wrote:

:)pmailkeey wrote: )> When is a light bulb a lamp? Well, Mr Edison referred to "lamps" in )> his
:patent - although I thought "light bulb" cropped up in there )> somewhere too. )> )> I'd gues the
:S-valve was patented - and if so, how was the name )> spelled there ! ? ) )Someone mentioned
:earlier in the thread that the valve was invented by a )company called Schrader, in which case the
:spelling "Schrader" would )certainly be correct.

I'd spotted that.

When made by other manufacturers, the spelling
:)they choose for their own product may also be correct (in much the same )way that "disc" is
:correct when referring to a CD, because "Compact )Disc" is a registered trademark).

Er, because they're discs ! Like floppy discs, hard discs and slipped discs.

:)A bit like hook and loop )fastener isn't supposed to be called velcro unless made by Velcro,

I was wondering about that recently where "velcro" came from !

:)elastane isn't supposed to be called Lycra unless made by DuPont,

And "spandex" ? :)

Now, where's me Jacuzzi !
--
Comm again, Mike.
 
On Mon, 02 Feb 2004 22:57:13 +0000, "Just zis Guy, you know?"
<[email protected]> wrote:

:)On Mon, 02 Feb 2004 21:04:34 GMT, [email protected] )(pmailkeey) wrote: ) )>When is
:a light bulb a lamp? ) )When it's being accurately described. A lamp is the little glass and )brass
:thing, the thing it fits into is a lampholder, light fitting, )luminaire or possibly electrolier if
:you're really grand.

I have pondered this muchly.

To me, a light bulb is a bulb which gives off light. A lamp is any of the following varieties:

Standard, desk, anglepoise, street (aka lighting column), head, fluorescent, bike, miners', oil,
parrafin, gas, carbide, reversing, neon, davey, safety, blow...

some of which have a light bulb in them.

--
Comm again, Mike.
 
On Mon, 02 Feb 2004 22:54:48 +0000, "Just zis Guy, you know?"
<[email protected]> wrote:

:)On Mon, 02 Feb 2004 21:04:33 GMT, [email protected] )(pmailkeey) wrote: )
:)>Considering the usual attachments for them mechanically open the valve )>during inflation,
:there'll be less air-effort to inflate the tyre than )>with prestas ! ) )Or there would be if the
:attachments for Prestas didn't also open the )valve.

The ones I've seen have been simple tubes which screw on and seem to rely on the fact there's no
spring behind the valve.
--
Comm again, Mike.
 
On Mon, 02 Feb 2004 22:57:13 +0000, Just zis Guy, you know? wrote:

> On Mon, 02 Feb 2004 21:04:34 GMT, [email protected] (pmailkeey) wrote:

>
>>I'd gues the S-valve was patented - and if so, how was the name spelled there ! ?
>
> Schrader.
>

This is correct. The inventor was George Schrader and he lived in New York. His father was a German
immigrant. It's possible that the family name was originally Schräder. (The umlaut signifies that
there's a missing 'e' so Schräder is really Schraeder.) It wouldn't be surprising if they had
changed removed the umlaut or 'e' to make it easier to spell. However, google searches for Schräder
and Schrader on German sites gives 15 times more hits for Schrader (pronounced Schrarder to rhyme
with yarder) and I don't think this can be explained by frequent references to tyre valves.

German cyclists often call Schrader valves 'Autoventile' - car valves. Perhaps we should do the same
to make life easier.

--
Michael MacClancy Random pleonasm - "I never make predictions, especially about the future."
- Attributed to Samuel Goldwyn www.macclancy.demon.co.uk www.macclancy.co.uk
 
On Mon, 2 Feb 2004 23:50:40 -0000, Mark McN
<[email protected]> wrote:

:)In theatre, where I earn my crust, IIRC the lamp goes into the )lampholder on the lamptray, which
:is part of the luminaire, which is a )posh but commonly-recognised name for a lantern. Calling
:lanterns )lamps is another example of Thurber's "thing contained for the )container".

And not a mention of "lamphouse" - the end of the lantern where the bulb ;) goes.

:) )-- )Mark, UK. [Who wonders what overlap - other than me - there is )between u.r.c. and
:rec.arts.theatre.stagecraft]

Could I interest you in a 48 channel 3-scene lighting desk ?

[Slightly on topic, I went to the public inquiry into the Metro extension in Birmingham. (Don't want
dangerous tram tracks on the streets.) There was me and 2 other fellers having a chat in a break and
it soon dawned on us that all three of us were into theatre lighting ! Turns out there's even a
techy's web site - URL I've forgot
!]
--
Comm again, Mike.
 
"pmailkeey" <[email protected]> wrote in message
news:[email protected]...

> :)>Considering the usual attachments for them mechanically open the valve )>during inflation,
> :there'll be less air-effort to inflate the tyre than )>with prestas !

> :)Or there would be if the attachments for Prestas didn't also open the )valve.

> The ones I've seen have been simple tubes which screw on and seem to rely on the fact there's no
> spring behind the valve.

I have at last count five different pumps which fit Presta valves. All open the valve as the pump
head is applied. It is not immediately obvious looking at the outside of them, but you can tell
simply by measuring the depth of the hole into which the valve fits. Alternatively you can try
only putting the pump head only partially onto the valve and see how easy it isn't to put wind in
the tyres :)

--
Guy
===

WARNING: may contain traces of irony. Contents may settle after posting.
http://www.chapmancentral.co.uk
 
pmailkeey wrote:
> Er, because they're discs ! Like floppy discs, hard discs and slipped discs.

I *was* going to point out that they would be floppy disks, hard disks and slipped disks. But I
thought I'd check the OED first, and found that "disk" is defined as:"US spelling of disc".

Bum.

But wait! I happen to have a copy of the Chambers dictionary dating from the 1950's. And that gives
"disk" as the primary spelling (although "disc" is acceptable).

I suspect that "disc" has only really become commonplace in the past 20 years, because of CD's. And
the compilers of the OED like to keep up with the evolution of the English language (hence their
acceptance of the irritating habit of using "data" as a singular noun), so my guess is that they've
changed the primary spelling accordingly.

--
Danny Colyer (the UK company has been laughed out of my reply address)
http://www.speedy5.freeserve.co.uk/danny/
"He who dares not offend cannot be honest." - Thomas Paine
 
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