Presta or Schrader Valve?
 

What's the difference? Which one is like your regular car tyre valve? What are French valves?

The old theory was that the Presta valve could hold higher air pressure better then a Schrader (car valve), but that doesn't hold water because semi trucks use Schrader's and they can have as much as 120psi for wide base tires, but then figure in the load and temperture and the pressure will be higher then that. So really the only real advantage is weight. The other slight advantage is that the Presta valve uses air pressure to prevent air lose and easier to pump by hand, whereas the Schrader uses a spring to prevent air loss and the spring makes it harder to pump by hand; also the spring could weaken over time resulting in loss of air pressure, where as since air pressure prevents the Presta valve from leaking rather then a mechanical spring chances of failure are less...except the Presta valves tend to be a bit more fragil-so it's a toss up.

I like the Prestas because they have a little lockring which secures the valve to the rim. This way, when you attach your pump to the valve, it doesn't push the valve down into the tire. It stays there nice an solid. This is especially useful when you are filling an empty tube.

as do schwalbe's

Good to know. That's why I come here. All kinds of useful tidbits.

As was pointed out in a very similar thread a month or more ago, Schrader valves, while they DO have a spring, most pumps that inflat them depress the spring as the pump head makes its seal around the valve. Therefore, there is little or no extra pumping effort.

Smaller valve hole in the rim for a slightly stronger rim & a lighter weight valve are, I think, the Presta valve's maim claims to fame compared to the Schrader. Maybe Presta construction is a bit simpler? I suppose there are better aerodynamics with the smaller Presta valve.

Anyway, do a search on this topic. It was argued/discussed at length, recently.

Like Mike says, I think one of the main advantages of presta is the smaller valve hole. This helps strength of rims and allows more customization of rim style, especially road rims because they are narrower. An advantage of Schrader is that you can easily add aftermarket sealant fluid such as slime to the tube. There are adapters available that screw onto a presta valve to allow you to use a schrader pump... can be useful at a gas station. There are also rim inserts available so that you can safetly use a presta valve on a rim drilled for schrader.

I don't like Prestas at all. Maybe I am doing it all wrong but when I come to pump the damn things up and loosen off the little nut (enough to let any air in) at the end and attach the little brass adapter thing and the pump, all the air starts rushing out and it is a race to see whether I can pump the tyre up before the air leaks out again. This doesnt happen with Schräder valves. At least with these all the air that you pump into the tyre stays in.

Ha, ha, ha, ha. I love it whenever this subject comes up.

"Presta valves hold air pressure better." My air conditioner uses a Schrader valve and is designed to hold the coolent at 200psi with no pressure loss for years at a time.

"Presta valves are easier to pump bacause Schraders have that little spring." Look at your Schrader valve pump head. See that little finger. That finger pushes the valve open so there's no difference in pumping effort. If you are strong enough to inflate a tire against a 100psi back pressure, that puny little spring wouldn't bother you much anyway. What can the rateing on that spring be? 0.1 lb/in? Probably less and you only push it about 1/16" anyway.

Actually, I do see some advantages to each. Presta valves require a smaller hole to be drilled in the rim. A smaller hole stands to be stronger, but that's not a place where I've seen rims fail. Schrader valves lose a bit of air pressure when you disconnect the pump because the finger holds the valve open for a bit. The air you hear from Presta valves when you disconnect comes from the pump hose. Schrader valves are easier to check with a stand alone pressure gauge. The very act of checking a Presta valve that way loses enough air to change the pressure. Schraders are much easier to inflate using my air compressor set up, but it wimps out at about 100psi anyway so I'd still have to use my floor pump. I'm going to guess that Presta's weigh less. If you let a front wheel rotate to a stop, Presta valves tend to stop at the top and Schraders at the bottom.

When I was mountain biking I liked to use rims drilled for Schrader but use Presta valved tubes with an adapter nut on the valve stem. That way my tubes were the universal donor for my riding buddies and my bike was the universal recipient for their inner tubes.

To me the biggest advantage that trumps everything else is to have all of your bikes use the same system so you don't have to monkey around with your pump when you inflate tires. I'm all Presta except for the wife's bike. I think that the rest of the stuff kind of balances out.

The new wheels I bought for my younger son's mountain bike came drilled for Schrader, but I use Prestas with thin metal washers and rubber grommets. It is a nice system, because you can use an inner tube with either type of valve in an emergency.

I don't worry about having the same valve type on every bike, because each bike has its own pump, and my floor pump is bilingual. However, since only my UO-8 has Schrader, I still think I'll convert it to Presta, to match the other 4 bikes.

I like the Prestas because they don't lose any air when removing the pump head. I do carry an adaptor though in case of emergency.

Sorry Retro Grouch but your incorrect...HAHHAHAHAHAHA...well at least in one area; anywhew the sites below debunk your "not any easier to pump" thesis.

see Presta heading at: http://www.sheldonbrown.com/gloss_p.html

and read this from Jobst Brandt: http://www.yarchive.net/bike/presta.html

And you do lose air pressure when you release the pump from the tube from the pump shaft, hose, and valve head as it is the sound of air escaping your tube. In reality, what you lose is minimal, so no need to fret.

The main reason I prefer Schrader valves is you don't have to have that little brass adapter and take it on/off everytime you need to fill the tube or check the air pressure.

Unless you have the correct pump

Even smart people make mistakes but in this case I'm willing to forgive you bacause you just repeated what someone else said without asking yourself if it makes sense or not. That might get you real good grades in school but it doesn't always make it true.

In this case, I'm going to stand by what I said until one of your sources can explain why my ideas aren't valid. Frankly, I think that they are both just plain wrong in this case because you don't use air pressure to push open the spring on a Schrader valve. Neither of them addresses that fact do they?

Jobst Brandt stated that Prestas are easier to pump with a pump head that has only a gasket.

Since all the shrader pumps I have seen lately have a means of depressing the spring without using air pressure, I would conclude that there is no reduced effort to fill a presta tube. My personal experience hand pumping both types of tubes bears this out. If there is any advantage of one valve over the other, it is insignificant.