Stretch

It's not the spring, its the air behind it!

Retro Grouch 

Come on! So what happens when the poppet valve on a presta tube opens? There's exactly the same amount of air pressure behind it for you to pump against.

Ed Holland

But the area of the valve inlet is less for a Presta than for a Schraeder. Physics tells us that force=pressure x area, so the force required to pump against a given tire pressure, using the same pump will be lower if one uses a presta rather than a Schraeder valve.

Ed

edit: I'm wrong.... and too clever for my own good. Of course air only goes into the tire when pressure in the pump is equal or greater than the tire pressure. If the same pump is used, the same force is required to push the handle to the same pressure. Sorry for the confusion

thewinwizard

Whichever your bike came with!!!

The Quiet One

Splonge: Presta or it could be Schrader and I'm not being indecisive.

Miele Man

hey there. Did you notice that the last post before yours was ELELVEN YEARS ago? LOL

Both have advantages and disadvantages. With Presta you have to be careful that when pumping with a hand pump you don't break the valve stem off. With Shaeder it's very easy to put tube sealant into the tube.

Cheers

AlexCyclistRoch

I'm surprised that after 11 years, nobody has asked how a Woods Valve compares......

dr1445

i find the schrader air chuck wears out before a presta air chuck with a floor pump. they get to 40psi and pop off, at that point you need a third hand to keep the chuck on the valve because the clamp no longer holds by itself.

fietsbob

Dont forget your valve caps!

P/V pressure differential closes the check valve in the stem.
S/V the spring in the valve core + the pressure differential close the valve

so... hand pump You have to use air pressure from the pump to open 2 things wanting to stay closed..

You can adapt a rim drilled for S/V to P/V with a reducer ,
but the bigger stem won't go in the smaller Hole to do the reverse..

I like my Schwalbe A/V (s/v) tubes on my Brompton , because they are secured with a ring nut ,
to use push on compressor hose ends ..

(like p/v ring nuts on stems , but the hole in the rim for s/v is bigger)

Bike Gremlin

What if I told you I prefer Presta for road bikes and Schrader for MTBs?

CrankyNeck

Presta might have a few small advantages, but overall Schrader valves are far superior. Lots of cyclists I know who have wide enough rims have drilled larger holes so they can use Schrader valves. I would do the same if my rims weren't aero-shaped and bit too narrow for safety sake.

KLiNCK

That would be Hank Schrader. A giant amongst DEA agents, home brewers and tire valves.

SquidPuppet

How so?

thewinwizard

Yes I did mate. I just thought I'd have a sense of humor. I also see this thread has been resurected!!

CrankyNeck

Schrader valves have an easily removable core (OK, more presta valves are now available with removable cores, but they're still not mainstream and you definitely pay for it), they are much more robust and thus a lot harder to damage (how many people do you know or have ever seen damage a Schrader valve?), and you have a lot more options for inflation in emergencies since that is the valve used on auto tires.

Gresp15C

About the spring in the Schrader valve, doesn't the pump head push the pin down? I don't think you're working against the spring when you're pumping a Schrader tube.

prathmann

That is correct. The first hand pump I bought for my old Schwinn Varsity was missing the little depressor pin and therefore relied on air pressure to open the valve. It was essentially impossible to use - every pump felt like I was pushing against 200+psi even when the tube was still uninflated. Took it back to the Schwinn dealer who first insisted that no pin was needed since air pressure alone would open the valve. Asking him to demonstrate quickly convinced him of his error and he went looking through his stock of pumps to find one with the necessary pin.

But Schrader valves at that time (pre-'75) did still have a disadvantage - the pumps came with a flexible tube that had to be screwed onto the valve. Then, after pumping up the tire you had to unscrew that tube but for the first few turns the pin would still be depressing the valve and you'd lose some of the precious air you'd just worked so hard to get into the tire. No longer a problem with thumb-lock pump connections, or even with better made screw-on connections that make sure the pin is no longer in contact before the airtight seal between the pump and the valve is broken.

GravelMN

Who digs up these zombies?

Both systems work just fine with minor +/- for each. I personally like Presta but I added an adapter to the back one on each bike so that I can use any kind of pump or compressor in a pinch.

Squeezebox

used to be with a Campy Record clamp on front derailleur you could screw on an adapter to the end of the bolt. I prefer presta just because, but I put an adapter on 1 on the valves just in case.
So with an adapter you can do presta to Schrader, but not the other way. So go with presta tubes with a tiny adapter and you have both.

Retro Grouch 

Why did you open it?

Check response #64. It's a guy, probably just like you and me, who likes to read the outrageous responses folks come up with in Schrader vs. Presta threads.

Gresp15C

My family had one of those pumps. I had to figure out how much to over-pressure each tire, in order to reach the desired pressure after losing air while unscrewing the valve. And of course we pumped 'em up to the maximum to keep those Schwinn steel rims from getting dented when we hit a curb the wrong way.

I still have the screw-on chuck, and use it for getting all of the air out of a tube while folding it up for my saddle bag.

Defeating the Schrader valve spring with pressure would be a tough job. The spring force isn't a lot, but the area of contact is tiny, leading to a lot of pounds per square inch. And that difference would remain between the pressure on the pump side and the tire side.

By the way, I have no dog in this fight, but I'm just curious about how things work.

marcw

I like shrader valves, all pumps can handle them.

Squeezebox

Any pictures of a woods valve? I have seen a few but only a few.

randomgear

One woods valve for SqueezeBox:


Imported to the US from the Netherlands last September.

Since an 11YO zombie thread is the best thing I've seen today.

GravelMN

Didn't realize it was a zombie until it was too late. Either these are coming up in a search or someone is digging pretty deep to find these. It's amazing how old some of them are and how many times they've been resurrected. No problem with feeding a zombie now and then, still some good information in some of them.