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Ride For Jesus 01-11-02 12:42 PM

Checking Air Pressure
 
Hey Guys, I hate to bother you again about the same subject, but since I'm new to presta, how do you check the air pressure? I screwed the adapter on all the way and the valve release ( or whatever it's called ) doesn't come up far enough to be depressed by a standard tire pressure gauge.
Should I buy another adapter, and cut it down to size? Do they make special gauges for presta valves? What's my best bet? Thanks, Jeremy P.S. This is my last post about presta valves -- I promise!:)

Richard D 01-11-02 01:00 PM


Originally posted by Ride For Jesus
Hey Guys, I hate to bother you again about the same subject, but since I'm new to presta, how do you check the air pressure? ... Do they make special gauges for presta valves? What's my best bet? Thanks, Jeremy P.S. This is my last post about presta valves -- I promise!:)
Yes they do make special gauges.

More posts on presta valves are welcome :D

Richard

D*Alex 01-11-02 04:31 PM

You need a special gauge made specificallyfor presta valves. It has a little button in the insert tube-that presses the valve.
Presta valves don't leak nearly as much air as shraders valves do. Tose pressure gauges blow too much air out, anyway. Inflate it to the correct pressure every week and you should be fine.

mike 01-11-02 06:50 PM

Welcome to the pain-in-the-@ss world of using Presta valves in the USA.

Switch to Schrader valves. You will thank me for this advice when you get a flat in farmland. A thousand people will be willing to help you, but nobody will have equipment with a Presta valve attachment.

The reverse happened to me in Europe when I had Schrader valves and everybody else had Presta valves. My saving grace was that European cars use Schrader valves, so once I made it to a garage, I could fix my tire, but that was miles and miles of walking. Meanwhile, about 12 bikers stopped to help me, but to no avail.

pat5319 01-12-02 03:14 AM

OR...

Flick the tire with your finger it the sound should be close to a "ping" rather than a "thunk", if you're unsure, have your local LBS check for correct pressure and then see how it sounds

Pinch the tire with your fingers, you should "just" be able to depress the sidewalls slightly. ( You want the tires "hard" AND a bit pliant).

Get a foot pump with combination prsta/schrader head equipped with a built in pressure gauge

Ride Inflated
Pat

DnvrFox 01-12-02 06:42 AM

The best way to check air pressure on a Presta valve is to hook up a floor pump with a built-in gauge and top it off at whatever pressure you want to ride (probably just a few strokes). Just takes a second, and your tire will always have lost air pressure just by sitting around, anyway.

Pretty soon, you will get a "feel" for how often you should do this. I used to do it daily, but now about every 3 days or so.

John E 01-12-02 11:35 AM

Sorry, Mike, I strongly hold the opposite opinion regarding valves for bicycles. Although I used to have Schraeders on the commuting/touring road bikes, I now use Prestas exclusively. I would not want to drill out my narrow road rims or even my heat-treated Ritchey mountain bike rims to accommodate Schraeders. I can pump more pressure into a Presta, lose less pressure per day from a Presta, and prefer the appearance of a Presta on anything other than a cruiser or StingRay bike. I carry a spare innertube, a small screw-on Schraeder adaptor (which I haven't used in years), and a convertible Zefal HP-X pump.

D*Alex 01-12-02 11:45 AM

Geez, why drill a perfectly ggod rim when a valve adapter is so small you can tape one under your saddle? Presta valves hold air so much better, I'd suggest that everybody should change their shrader valves to prestas!
With one of those little adapters, even 'farmer brown' can give you emergency air, so what's the big deal about checking pressure? Fill it until it is firm. If you need to be anal about pressure, buy the presta gauge and leave your rims intact!

Geronimo 01-12-02 12:30 PM

I usually just screw the adapter onto one of my valve stems and leave it. Harder to lose that way.

MichaelW 01-12-02 01:04 PM

My track pump has a guage, and I take my 28mm tyres to 90psi. With a mini pump I struggle to get above 80.
Ive never had the need to borrow air from anyone. I find that a bike pump provides sufficient to continue a ride.

How high can you take Schraeder valves. When I used them, I always seemed to lose that extra bit of pressure in a hiss when I removed the pump.

Ride For Jesus 01-12-02 02:57 PM

Yes, presta valves do seem to be better suited for bikes, and with an adapter ( which is so tiny and insignificant weight-wise ) handy you'll never have a problem. Thanks again guys!
Jeremy

P.S. Mike, I used to feel like you until my recent conversion to presta. If you haven't tried 'em, give 'em a try; you might just change your mind! :)

LittleBigMan 01-12-02 10:15 PM

I use prestas, but only because they came with the bike.

I thought the main difference was in their ability to maintain higher pressures. If I had a tire fitted with a Schrader valve, I probably wouldn't waste my time trying to change it.

Mike, you are having fun on the road, aren't you?

(Say, 12,000 miles last year ain't bad, for a Schraeder man... :) )

mike 01-13-02 10:46 AM


Originally posted by Ride For Jesus

P.S. Mike, I used to feel like you until my recent conversion to presta. If you haven't tried 'em, give 'em a try; you might just change your mind! :)

O.K., guys, I am willing to listen. Is there really an advantage to Presta valves?

Yes, I have used Presta valves, but I still don't see the advantage - for people living in the non-Presta valve world of the USA. Of course, in Europe, Asia, Africa. Hmm, maybe everywhere besides the USA, Presta fitted pumps are easy to come by, but in the USA, if your Presta fitted pump fails, or if you lose it, or whatever, you are screwed until you find a bike shop or another rare biker with a Presta valve pump.

Oh, I suppose the valve is easier to repair - if you have the parts you need, simple though they are.



Granted, I am not using really high pressure tires, which may be a Presta valve advantage.

Is it the weight advantage? How much weight could you save? More weight than a good haircut would get you?

Seriously, what's the digs on Presta valves?

Ride For Jesus 01-13-02 12:44 PM

Dear Mike,
It's only been a few days now since I first started using prestas, and why you ask? Some feel that they look sharper on a bike (I tend to feel the same way), some feel that there is a weight advantage (I'd have to see the evidence on that one), but my sole reason for converting is the high pressure thing (I want my tires at the maximum level that they can hold). I've got high pressure tires, and the schreaders just wouldn't hold it for very long. The prestas seem to be doing better -- knock on wood.
Believe it or not, I'm still using my frame-mounted schreader pump. I can't see buying a presta pump when you can get a presta-schreader adapter for a buck; you just screw it onto the end of the presta, and bada-boom! Instant schreader! You can keep it, as a couple guys mentioned, on the stem or under the saddle, or like me, in my wallet with my change.
But in all reality, if you're not into high pressure, I wouldn't even worry about it. The important thing is that you're riding, and having fun doing it! You're cool Bro; I hope to talk to you again sometime.

Sincerely, Jeremy:)

roadbuzz 01-13-02 08:02 PM

Probably the biggest drawback to a Schrader valve on a typical lightweight road rim is that the size of the hole would weaken it significantly.

Geronimo 01-14-02 02:33 AM

a small benefit, but a benefit none the less is that the presta valve is held closed with air pressure only. Schraeder valves use a spring in addition to the air pressure, and every time you have to pump a tube up at road/trailside, you have to defeat that spring and work that much harder with your frame/mini pump. in short, prestas are slightly easier to inflate at any pressure (you can even blow them up like a baloon to get things started).

D*Alex 01-14-02 08:09 PM

to the best of my knowlege, nearly every bike pump sold in the US is presta-compatible. All you need to do is unscrew the head, pull the little 'finger' out, and put the plasic 'donut' in backwards. All Zefal and Blackburn pumps are like this.
If this fails, a little 49 cent presta-shrader adapter is all you need.

pat5319 01-14-02 10:12 PM

Why presta? ( vs Schraeder)

Prestas:

hold high presssure longer
inflate to higher pressure
more durable
lighter ( I hate to give that as a reason)
will inflate with ANY pump with an adapter
the smaller hole required makes for a stronger rim

Ride Presta Ride COOL
Pat

john999 01-16-02 07:24 AM

Presta valves :

- Tubes are much more expensive.
- You can't get tubes in country towns if you're touring.
- If you lose the adapter (or it's stolen) you're stuffed.
- They are more troublesome (sticking, leaking) in my experience.
- They hold pressure better - so what ? Most pressure is lost through the tube ! (punctures, etc)

John E 01-16-02 08:43 AM


Originally posted by D*Alex
to the best of my knowlege, nearly every bike pump sold in the US is presta-compatible. All you need to do is unscrew the head, pull the little 'finger' out, and put the plasic 'donut' in backwards.
One exception, Alex -- the Schwinn dual-function CO2 cartridge/minipump thingie speaks only Schraeder.

Thirty years ago, when I asked Charlie Harding (C Harding's For Bikes, West Los Angeles CA) why Schraeders were so popular on bicycles, even though Prestas are easier to inflate, he replied, "Because John Q. Public inflates his bike tyres at a gas station instead of by hand."


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