jrg1244

Just got back from a quick 12 mile ride, but before I left, again, I broke the little nut off the presta valve stem. The little threaded rod breaks and sometimes the tire will still hold air while other times I get the whoosh, and need to stop at the local shop to get a fresh supply of new tubes. It seems to have started about a year ago, when I bought a new floor pump, the Park Tool home mechanic floor pump. I'd bet I've broken 6 or 7 of them off since then and it's starting to get really annoying. Maybe I'm using the chuck wrong? Anyone else with this issue, or this pump, care to weigh in? Should I get another pump?

Berg417448

I have that same pump and have used it without issues for years. It maybe your technique that is contributing to the issue. It might be helpful to watch some videos to see if you are attaching the pump head correctly. Sounds as if you might be bending it instead of putting it on straight when attaching and removing.

Daniel4

I've broken lots of those until I figured out how to pump presta valves properly.

Make sure your pump has a flexible hose and when you're pumping, keep it flexed - like having a big arc. Don't keep it straight and taught.

wipekitty

In most cases, the little nut does not need to be completely unscrewed in order to inflate the tire. Try giving it maybe 2-3 twists. I bent a bunch of those suckers before trying this technique.

Brocephus

This is why I got in the habit years ago of using a schrader adapter. The presta's aren't as much of a problem when using a floor pump at home, but out on the road, pumping up a tire with my Silca frame pump, that you just can't stabilize like a floor pump, that's where I had this problem. The screw-on schrader adapters protect the fragile presta stem, and since using them routinely, I don't think I've even bent a presta stem, much less broken another one.

jrg1244

I'll check out the videos as suggested... It may be that I'm pushing the chuck on too far, then when I release the lever, I'm applying enough sideways force to break the nut off. Thanks for the suggestion to only unscrew a few turns. Will try that with my new (as of this morning) tube!

Gresp15C

Indeed, I've also given up on Presta pump heads. I found all of the adapters that I've collected over the decades, and put one on each bike, plus one with the pump at home. I've only had one nut break off, but have lost several tubes due to the weakness of the joint between the stem and the tube.

Brocephus

Yup, same here. I've kept one on every bike I've owned, for years, and keep a spare in my road bike's seat bag, in case I fumble one into the weeds while fixing a flat way out in the boonies somewhere.
I haven't even pumped up a tire at home without using one in longer than I can remember. They basically fix the main weak point of presta valves, there's no downside IMO.

BirdsBikeBinocs

Where do I get these Schrader adapters.??

Daniel4

Any bike store has them. They also come with the cheap ccm floor pumps.

HerrKaLeun

If you have a wide enough aluminum rim you can use a round file to enlarge the hole and use Schrader valves. I did that upon converting to tubeless and never looked back. No adapter needed, any car or gas station can pump up your tire etc.

For on the bike I got a mini pump with a hose. But yes, i see how you can break off that tiny thing. especially when removing the chuck after inflating and you try to hectically not waste any air.

speedevil 

You don't "waste" air when removing a presta valve chuck. The valve closed when you stopped pumping more air into the tire. The only air that escapes is what is in the hose.

Schrader valves don't work this way, the valve is held open against spring pressure, and air will escape from the tire when the chuck is removed. Once the spring closes the valve no more air will be lost. it's a different design that works fine for low pressure applications, but the presta design works better for use at higher pressures.

Mad Honk 

jrg1244,
I have one pump dedicated for Schrader valves and one for Presta valves. I throw the factory head away and use a Silca pump head. Cost about $30 and it goes straight on from the top so no side twisting. You can upgrade to the newer pump head that costs $65 but it is a thing of beauty, and works flawlessly. Side release instead of top so no extra pressure on the valve stem. As others have said I keep a presta /schrader adapter with all bikes in case I am out in the boonies and can only find a gas station with schrader chucks. In the shop I use a modified Milton blower nozel with a flex hose attached to a Silca head that allows me to use the compressor to fill the tires. Smiles, MH

Phil_gretz

I only now buy tubes with replaceable stems. This serves with extenders for aero rims as well as any failures with traditional length stems. Stock up on valve assemblies and Teflon tape...

GlennR

They're usually in a jar next to the cash register.

It's one of those things people lose all the time and and buy 2-3 at a time.

BTW... never broke a presta valve.

Brocephus

And I've never lost a schraeder adapter.

GlennR

Neither have I, but that's because I never needed one.

These days most pumps have a head that fits both.

Brocephus

Sure, I realize that, both my floor pumps have dual capacity. And I realize plenty of folks have no issues with prestas, but the fact remains that they are thin, fragile pieces of metal that are easily damaged, which isn't helped by the fact they're so frequently used.
I was just making a suggestion to the OP that his problem could be easily and inexpensively avoided with the use of a schrader adapter, which does in fact mitigate much of the risk, as has been attested to by other posters.

Brocephus

Great suggestion ! I got curious and just took a look around.....
https://www.treefortbikes.com/Q-Tube...-Cores-Bag-Ten
Pretty inexpensive way to sidestep the weak link in the system, and along with a good patch kit, keeping tubes running indefinitely.

HerrKaLeun

Schraeder valves are used on refrigeration systems with up to 500 psi. Also on shocks. I think they can handle even roadbikes.😎

The presta valves I had release some air when you touch that "screw" and move it laterally. I assume if you don't pull up the chuck exactly straight.

I grew up with what I believe is referred to as Dunlop valve. Only very few high end bikes had what was referred to as French valves. Of course none of the common pumps worked for those.
Then MTB came with Schraeder valves and life got easy, we could just use the already existing car infrastructure.

JohnDThompson 

Breaking the nut on a presta valve is an indication of poor technique. You need to apply and remove the pump head directly, not at an angle.

Fortunately, most modern inner tubes have removable cores, so when this happens you can simply replace the broken core with an intact core. Replacement valve cores can be purchased separately or salvaged from discarded inner tubes.

tntyz

I've broken plenty of presta valves with my Planet Bike pump in the past. A few things I've found to the help reduce the chances of breakage:

1. Unscrew only as much as needed to get air through the valve. Maybe 1-2 turns?
2. Rotate your wheel so the valve is at the top pointing down. When removing the chuck you're pushing down instead of pulling up.
3. Don't push the chuck on very far. It doesn't have to be jammed down on the valve to get air through (at least on my pump).
4. Put a new chuck on the pump. Mine wears out and then I violate #3 .

JanMM

Even though I’m not amazingly coordinated, I don’t recall ever breaking a Presta.

MikeyMK

ThermionicScott 

Use one hand to hold the pump head straight while flipping the lever with the other. You're probably allowing the pump head to get crooked and bend the valve. I broke off one Presta nut years ago and learned my lesson.