Bicycle Mechanics - Presta valve torn off

I got a flat the other day when the valve stem partially pulled out of the tube. The valve often rattles and I stopped a few miles from home and gave the ring nut a few turns to quiet things down. I think at 120 psi this maneuver (which I repeat once a week) ripped the valve right out after 1500 miles. This is the first flat with Armadillos, and you can't fault the tire! Anyway, has anyone tried double-nutting the valve stem with a nut on the inside? Is that more likely to cause problems? My rims have a medium-deep V. Any other bright ideas to stop the rattle? Does anyone leave the ring off their presta valves? What is that thing for anyway, as the air pressure will never let the valve move into the tire? Thanks.

The usual way to handle presta valve stem nuts is to discard them. They serve no useful purpose and can, as you discovered, over-stress the valve base if tightened too much.

The only time they are of any use is when first inflating a new or repaired tube as they keep the stem from retreating into the rim until a bit of pressure has built up. You can do this easily by pressing your thumb on the tire over the valve until it's held in place so the nut isn't really needed here either.

^^^as good as it gets^^^

OK, I'll not use them, but the packrat in me insists on keeping them since they're such well machined little things. I'll try a wrap of electrical tape around the valve to see if this effectively muffles the rattle. Things were so much simpler with my traditional schraders on the MTB.

try a drop of lock-tite before you put it on. Then the nut can serve its' purpose, and won't rattle, so you won't have to keep tighening it.
BTW, I've had way more valve failures with schraders than prestas.

OK, I'll not use them, but the packrat in me insists on keeping them since they're such well machined little things. I'll try a wrap of electrical tape around the valve to see if this effectively muffles the rattle. Things were so much simpler with my traditional schraders on the MTB.
Are you running prestas in shcraeder drilled rims? If so, get they make a shim to put in the hole to size it correctly. Also, what you were hearing was probably the loose nut anyway. It if it is not there, it cannot make noise.

How tight is that loctite going to hold the nut? If you have a roadside flat are you going to be able to get the nut off if you need to replace the tube? I just leave the nut off.

One thing you might want to check: next time you have the tire & tube off the rim, check for sharp burs around the stem hole inside the rim. These are often not cleaned up very well when the rim is made.

No nuts.

I have nutted presta valve tubes on all of my bikes. I don't have any problems with them at all.

I have nutted presta valve tubes on all of my bikes. I don't have any problems with them at all.

+1

The usual way to handle presta valve stem nuts is to discard them. They serve no useful purpose and can, as you discovered, over-stress the valve base if tightened too much.

The only time they are of any use is when first inflating a new or repaired tube as they keep the stem from retreating into the rim until a bit of pressure has built up. You can do this easily by pressing your thumb on the tire over the valve until it's held in place so the nut isn't really needed here either.

HillRider is right on. They may be handy when first inflating, to support (especially long stem) presta valves. After that you can discard them. If you have a rim that tends to cut into the area around the stem, take an old tube and make a washer out of it, place it over the valve before installing the new tube. That will give you an extra layer of protection for "safe inflation."

If you just can't discard such cute little nuts, make them into a necklace!

The usual way to handle presta valve stem nuts is to discard them. They serve no useful purpose .... The only time they are of any use is when first inflating a new or repaired tube as they keep the stem from retreating into the rim until a bit of pressure has built up.Agreed. I learned to pitch those things decades ago when riding dirt bikes. If the valve stem is left to its own devices, it will start to lean and indicate that the tire is slipping on the rim and needs attention. In fact, most tubular tires have no threads on the valve stem for those things.

Agreed. I learned to pitch those things decades ago when riding dirt bikes. If the valve stem is left to its own devices, it will start to lean and indicate that the tire is slipping on the rim and needs attention. In fact, most tubular tires have no threads on the valve stem for those things.

Also, it's arguable that if a tubular goes flat all at once, you WANT it to come right off the rim immediately. If you nutted the valve, it would stay on in that point, making the bike pretty unstable.

no nuts as well