You can get little inserts to adapt a schraeder-drilled rim to accept a presta stem properly.

http://www.bikemannetwork.com/Mercha...-SC/RM9002.jpg

aluminum version:
http://www.bikemannetwork.com/biking/p/RM9002

rubber version:
http://www.bikemannetwork.com/biking/p/RM9001I

another rubber version:
http://www.loosescrews.com/index.cgi...id=40029521248

nonsense
more nonsense, they're in the rim's "shadow" and the wieght difference is marginal

both effects would be close to immeasurable

hey you might think that schraeder tubes hold air better since older tubes (as in three decades old) are thicker and the air leaks out more slowly. anyone know when they made that switch? it's a good idea to use an adapter with presta tubes, especially with hand pumps. when i remove pump heads and i know it's tight, i'll gently flex the stem against the side of the valve hole in the rim to help me get some more resistance so i'm not pulling the valve out of the tube.

the presta caps aren't as important as the schraeder caps (which are pretty inessential themselves) but i don't see any reason not to run them.

The mech at my LBS (actually former mech/manager) showed obvious disdain for reflectors, dork disks, stem nuts and caps. Seemed to think one looked like a newb with any of those things. When I upgraded wheels, the new ones came sans reflectors and the dork disk, so I ride without them. Stems and caps are kind of on again - off again with me. If I'm using a repaired tube from the hook marked "good tubes" I will ignore the stems and caps. Only when I am using a brand new tube will I put those on, maybe. One flat, and I've usually lost 'em.

I really do like the threadless tubes, though my shop doen't regularly carry them.

my only complaint about presta valves is that the small screw at the tip of the valve (the one you screw and unscrew to hold and release air) can often break off with the force of the NY Kryptonite chain being pulled through (like immediately after unlocking) the wheel. Another little thing i learned while messin'.
Though I did find just having a valve cap greatly reduced the frequency of this problem. One could argue to not lace the kryptonite chain between the spokes with the valve but that takes a whole nother second!

From a time / economy of motion perspective
I like Schaeders better.
I dont have a problem with Prestas, though....
Split Rim truck tires are Shreader valves and they have
air pressure equivalent to a small bomb so if someone loses
one on a bike it means they didnt screw the core in right.

Almost every time I go to pump up a Schraeder, I have to stick the pump head pretty tightly onto the valve, thus getting the pump head stuck on the rubber on the valve stem. This makes it pretty difficult to remove the pump head, not so with Presta.

Also, unthreaded valve stems have been nothing but trouble for me. I bought some that'd blow the pump head off at 80 PSI because there wasn't enough metal on the valve stem to hold the pump head on. GO THREADED PRESTA (preferably 60 mm stems).

i'm partial to presta threaded. the reason being that the nut on the threaded stem prevents the stem from being pushed in and puncturing the tube when you're trying to get the pump head on - this can be a MAJOR pain in the ass. it's a little more convienent than using a set of needle nose pliers on an unthreaded stem though. i use a park tool home mechanic pump at home, and a topeak road morph on the road. both chucks have held onto both types of presta valves inflating to around 140PSI.

Presta's are way easier to deal with when changing a tube on the road. Inflate them by mouth and bleed as necessary when installing the tube.

Presta valves mainly fail for me when the tube rubber at the base of the valve stem cracks. The long presta stem and the difficulty of getting a pump to seal to it well, and then to release, cause more stress to the tube. The schrader adapters help a little bit, but they're never as robust as a wider schrader stem. However, with narrow rims there isn't much that can be done about it.

Anyone can make something 'cheaper' but not cheaper AND better.
You gets what you pay for . . .

I cant belive the problem all you cyclist are having with a simple presta stem. Its just a fricken stem,not brain surgery. I'm starting to really worry about you.

2 me a schradeder rulz cos its ready to go and practically a universal standard, no adaptorneeded -presta is jus another thing to learn about and another part to lose- ill adapt but i wont like it- i like schraeders simplicity tho' and theres dope valve caps.

^^^it pretty obvious why you can't grasp the 'theory' behind a system as complicated as Presta valves... you can't even comprehend the english language at a second grade level, much less the high level physics require for 'lefty loosy, righty tighty'

my favorite thing about bike forums is how nice everyone is.

it's easy to be a ******* on the internet because you don't actually have to talk to the person face to face.

My favorite thing about bike forums is how a stupid thread you started in a moment of boredom can rise from the dead and resurface days, weeks or even months later.

sniff sniff... these things don't age well

Jerk!

now to run into you on the street somewhere...

Yep,its easy to be dickless on the otherside of the screen. Makes some brave.

Some of us are dicks in person too... please don't assume that we are nice in real life.

Good point.

You can suck the air out of a presta without taking it apart. I do this after I have repaired a tube and want to store it. A little masking tape to hold the valve head down. You suck using your tongue as a diaphragm - no need to inhale. You can pull the small volume of air out of that sucker in no time flat - flat as in making the tube as flat as possible for folding and stowing in your bag. It's a small thing, but try doing that with a schraeder.

Caruso

....

What's wrong with loosening the valve core with the tool that's always on my bike and removing the air from my schraeder tubes? :p

Personally, my only experience with Presta has been helping other people patch holes (you know the ones.... you see them out there on multi-thousand dollar bikes, no pump, no kit. to quote the last guy: "The bike's brand new, I didn't think I'd need my pump and patch kit." ....)

My daily bike runs at 110 psi, and I top it up about once a week. So the crap about them not holding air is just that, crap.

I'm supprised so much trouble with stems. I've never broken one,torn one or had a problem with one,lucky i guess or i'm just careful.

MTB forks and shocks use schrader valves, and they hold much higher pressures than 120psi. most rear shocks can hold up to 300psi. and as the shock compresses, the pressure rises exponentially.

...of course, with a schrader valve, the actual seal for the valve is the valve cap, and on shocks, the caps are metal, with an O-ring in the top to properly seal it off, but plastic ones work just as well. i prefer presta valves, but for my tubless wheelset, i'm going to switch to schrader, so i can't have to use an adapter with my combo portable shock/tire pump. i hate adapters more than i hate people who skid on tubulars...and i hate people who skid on tubulars a whole lot.

I still ride bmx, and I can assure any naysayer that a Schraeder valve can hold over 130 PSI while taking heavy impacts without fail.

Tradition has a lot to do with it, I think. None of the "advantages" to a Presta valve really seem to carry any weight.

Oh yeah! well....well....Presta looks better! On top of that, it's newer technology so it makes me feel more advanced than you primitive Schraeder users.