tatfiend 

Does either type have any advantages or disadvantages?

I note that Michelin tubes use unthreaded and almost everyone else seems to use threaded.

Bone Head

Personal experience: My floorpump head slips off the unthreaded stems but grips the threaded.

urbanknight

^ Yep. The pump head stays on more easily with threaded, but that also chews the rubber seal more quickly. I really don't care which type I have.

Steev

I like the unthreaded so that the pump head comes off without force when the clip is released. I know of no functional difference. Seems my LBS rarely has unthreaded in stock. When I last asked, I was told the tri people had cleaned out the unthreaded stock, don't ask me why the preference.

z415

Threaded also comes with a screw-on nut type thing hat helps hold the tube via the valve with pumping up from flat and installing the tube. Other than this and what is listed above, there is not difference.

Most LBSs I've been into seem to think the threaded ones are useless - this is mostly coming from the college racing salespeople though.

Happy Thanksgiving.

ScrubJ

I prefer the un-threaded myself.

frankenmike 

If you have very deep rims, most valve extenders only work on threaded valves.

operator

That nut is as worthless as not knowing how to inflate a tire without one. The only thing it does is help unexperienced flat changers pinch the valve area against the tire/rim, and for people who do know how to use it, it's slower to thread that stupid thing on.

Road Fan

I like threadless, and have no trouble with the pump head slipping off, if I tighten the pump head. The Silca head is adjustable, to improve the head-valve seal when necessary.

Road Fan

nitropowered

Most tubes now a days are threaded. Its getting harder and harder to find unthreaded tubes.

ScrubJ

"Giant" branded tubes are threadless. I can't imagine them having the market cornered on threadless tubes.

Al1943

Michelin invented bicycle "balloon" tires and tubes. All Michelin tubes are unthreaded, and less damaging to your pump chuck O-ring.

Norcal02

I prefer the nonthreaded ones, but the only ones that I've gotten locally without the threads are Novara. I've heard some stories about them not being so strong around the area where it connects to the tube and them breaking there. In fact, I've been through some because of that, but none while riding strangely enough. In fact today I just replaced my front tube because it still had a threaded stem on it...the pump would NOT separate from it and I put just too much force on it, tearing the stem out. < Noob.

Soil_Sampler

vredestein
torelli
michelin
hutchinson

they all make smooth presta valve tubes.

tatfiend 

The Michelin tubes I got recently have thicker rubber around the stem base to reduce the chance of failure there. So did older Continental tubes but the latest ones purchased seem to no longer have it.

thorsteno

The Michelin tubes I have are smooth but have 2 or 3 butressed grooves about 1 cm from the tip of the valve. The grooves give a little purchase for the pump head. I've only replaced the rubber washer in my SKS floor pump once in 4 years. Ususally air up the commuter to 100 psi and the road bike around 130.

capsicum

I use threaded shrader on my motorcycles, they come with double 12mm nuts to really lock 'em in place. Helps keep the tube from shifting during install, loss of valve stem into the tire in the event of a flat, and during low pressure use when the whole tire may slip a little.

(One of the bikes has actual bead locks installed, and the other has a knurled bead seat to help prevent slipping in the first place.)

My topeak joeblow floor pump has adjustable preload on the stem gripper so it holds well, but applies and releases without excess force and wear. Its that little screw on ring at the very tip.

fuji86

The new XLC brand 700x20-25C's (48 mm stems) that I just installed were unthreaded. No problems with the unthreaded valves other than a mental perception of replacing threaded (as they replaced Innova threaded Presta valve tubes) with threaded tubes. I had no issues with the pump or valves. I'll admit, I think the threads & lock nut looks pretty cool, but I've gotten over that already, the tires have air in them now and the bike is ridable again, which trumps a cool chrome lock nut anyday. I have 30 mm deep V rims too.

Perhaps additional advantages to the threaded valves, the locknut serves to keep larger foreign objects and dirt out of the rims and tires. Much like the larger bottom of a Schrader valve seals the stem hole in the rim. Run thru a deep enough puddle of water and no valve seals completely. The locknut also serves to keep the valve from pushing into the tire when it's completely flat and you're trying to get the hand pump onto the valve to air them up, but pulling the hand pump off the valve is easier with the unthreaded. Maybe the threaded valves hold in place better when the tubes are ridden as under-inflated over time ? That is it drifts less, we've all seen the leaning valve stem from riding under-inflated.

fietsbob

un threaded? You talking glued on sew-ups?...

NB
there is an Unthreaded zone between the cap coarse theread and the ring nut
fine threaded portion .
that is where the pump gasket seals best , with a silca track pump,
[my favorite presta pump]
and It is a reasonable chore to remove the hose , which is holding air pressure.
shove it on further and A its hard to remove , and B it wears out the rubber seal
in the pump head needlessly..

Mr. Fly

I believe the "unthreaded" valve stems are still threaded at the tip, which is where valve extenders and the plastic valve caps thread on.


At least some of Michelin's 26" tubes have threaded stems, because that's what I have on my commuter right now.

JTGraphics

I use the unthreaded stems on my road bike myself not because of that but because I like the Michelin tubes.
While I do also have several of the threaded stems which are on some of my other bikes because get them cheaper like my commuter.
I have never had a problem with the smooth stems slipping off while pumping up my tires also.
Use what ever you like if the price is right their is no real difference as far as the stem goes.

BCRider

All the stuff I've seen on dirt bikes say to leave those nuts loose or run them up and jam 'em against the valve cap after using them to get the first inflation air into the tubes. That way if the tire and tube slip a little it won't rip the stem out of the tube. Especially when using lower pressures common in off road use. THis was hammered home to me back when I rode trials bikes that only used from 7 to 12 psi to get the tire really squishy and give a huge contact area. It's a good thing you're using the bead locks or you probably would have ripped a few stems off by now.

LesterOfPuppets

I like 'em smooth cuz it does seem to wear out my pump's rubber at a slower rate.

DOS

Unthreaded, I recently discovered them and love them. My pump heads don't slip at all, but they disengage easily when I want them too.