Of the 3 types of valves, I like modern Dunlop valves the best. Has the advantages of a presta without the little stem and nut, plus the valve is easier to remove than the other 2.

That would be incorrect. Walmart (aka Hellmart) sells presta tubes for 700C tires. I've seen them in a number of Hellmarts around the country.

They also sell 700C tires. Not good ones but they are better than Continentals

Our local hardware store has presta tubes.

It's more like an example of Sayre's Law.

Tractorlegs stands corrected Ouch! I'll let go of my Conti's when they unwrap my cold, dead . . . . well, you know.

If they come in shares, I'll gladly give you mine. I've had far too many Continentals fail me to use them even around town. The straw that really broke the camel's back was 4 blowouts on two tires within the first 26 miles of a 2 week bike tour. One of them occurred within two miles of where I parked my car. The 4th one caused me to thumb a ride back to my car and made me reroute my tour. All of the blowouts occurred on tires that had been pumped to the suggested pressure.

I used the Continentals for the rest of my tour but I had to run them at 20 psi lower than the suggested pressure. There's nothing quite like riding squirmy tires for 400 miles. I'll use anything...including the Bells sold at Hellmart which are just awful...over Continentals.

Wow, I don't blame you for avoiding Continentals. My experience is completely the opposite. I've used Contis since 2006 (9-1/2 years now) and haven't even had a puncture. I used the sportCONTACT for four or five years then switched to Touring Plus, both @ 700 by 32 and 80 psi. I ride modestly, around 1500 to 2000 miles per year - -

I do not blame you though, if they did to me what they did to you I'd move on.

Quote:

Originally Posted by GerryinHouston

I've read that you can buy a Presta to Schrader adapter. Can you leave that adapter permanently on the Presta stem (and capping the valve with the Schrader cap?).

You can, but another advantage of the Presta valve is that when you tighten the little stem part, it's a positive seal. If you leave it loose, you can (theoretically,anyway) have sufficient centrifugal force (because the presta valve has no spring to hold it shut) to leak air out. So you can't leave the adapter on and the valve not tightened down. So you'd have to remove the adapter, loosen the stem, replace the adater to fill your tire, then repeat the process to tighten the stem. Another downside (minimal) is the small amount of rotating weight at the rim. Minimal, especially if you use aluminum rather than brass adapters. The Schrader valve has a built-in spring, and so in normal cycling* will not leak air.

A real expert (Jobst Brandt, RIP) weighed in on the Presta advantages in response to a question, from Presta valves (Jobst Brandt)

> If anyone can tell me the advantage of Presta, I'd like to know.

Two main advantages are the slender profile that doesn't cut as large a hole in the rim, and the lack of a spring that allows easy pumping with a simple pump head (one with no features except a gasket). The slender form is probably the more important feature because the valve hole in the rim describes the minimum cross section and therefore the ultimate strength of the wheel. When the rim yields at the stem hole the wheel fails. If this cross section is small it limits spoke tension that is the essence of wheel strength. A rim may feel heavy and look strong, but if you consider the cross section at the stem hole it loses much of that robust appearance.

*Jobst pointed out in the same thread that a world-record attempt at 160mph resulted in a
Scrader valve leaking due to centrifugal force on the valve stem.

I have come to prefer Presta.
But I could go either way.

Incorrect.

My wife's hybrid bike with 28c tires has Schrader valves. All of my bikes with 25c, 26x1.5 and 26x2.1 have Presta valves, and I prefer them far and away over Schrader. I had a Schrader tube on my wife's bike completely fail once when the entire valve stem pulled out of the tube as I was trying to remove the pump head. In general I find that removing the pump head to be more difficult on Schrader valves than on my Prestas.

I don't use the Presta caps that come in the package as those are meant only for packaging to prevent the valve from puncturing the tube in transit. So for me it's easier to just unscrew the Presta valve than it is to unscrew a Schrader valve cap and then have to put it down somewhere or hold it while pumping the tire. I do not like to leave Schrader valves uncapped (on both cars and bikes). I also prefer threaded Presta valves with the retaining nut since it keeps the valve from pushing back into the tire when I'm trying to attach the pump head. Putting the pump head on an empty Schrader tube/tire/rim can be pretty difficult sometimes.

blondes have more fun but brunettes are more fun

Incorrect. Your experience with breaking Schrader valves is similar to many others' experience with breaking presta valves. I have seen more Schrader valves get gummed up and leak air (which can usually be fixed with a Schrader valve core remover and/or a bit of spit) than presta, but I have seen far more presta valves get broken or torn out of the tube. It makes little difference if you have more pumping finesse than a gorilla, though, and Schrader are obviously more convenient on an 'everyday' bike that might need its low pressure tires topped up at a gas station or by a passing motorist who keeps a compressor in his car.

Now is the schrader or presta and with or without a helmet, and what do you lub your chain with?