Today I mounted some 30X3 tires and metal stemmed tubes, with the flaps. I put the tubes in the tires, put the flaps in around the inner side of the tube, Installed the bridge washer and nut down against the flap in the way they should be. Then I got the tire on the wheel, at which point I bounced it around hoping that would help seat the tire, and then I put just enough air into it so the tire poofed out and seated nicely in the rim. Everything seemed perfect. I put the wheel on the car and then went to air it up to 55 psi.It was then I heard a small popping noise and the air started coming out through the valve stem hole. It was not a happy moment. When I finally got the tire off I found that the metal stem had popped out of the tube! This was a rather new tube. The base of the metal stem measures 11/16 (the flat base part that bears against the tube wall).
I don't know what the heck I could have done wrong. Anyone have any ideas? One front wheel is on the car and seems OK, but I still have to mount the rear 30X3.5 tires I don't want to go through this again, or have to worry about it while driving.
Might try adding a little rubber cement. How to install metal stems.
The flap has nothing to do with the tube. the tube needs the bridge washer and nut fitted to it so the valve is clamped to the tube.
Without the flap the tube has to hold air by itself.
I have successfully installed dozens of original type metal valve stems and the procedure I use is nearly identical to that depicted on the sheepisland site referenced above. However, rather than filing the nub until it is flat or smooth with the tube, I leave it standing about the thickness of a penny. Experience tells that leaving a little more meat increases the likelihood that the bridge washer and stem when tightened will form an effective seal.
Experience also tells me NOT to use any type of sealer, or bead lubricant. Doing merely allows the tube to rather easily squish and slide away from the valve stem when the nut is tightened.
Like mileage, your experience may vary.
I put the tube in, then put the flap in around it. with the stem coming thru the hole in the flap. Then I installed the bridge washer with the tangs away from the flap/towards the wheel rim and tightened up the nut. Then I brushed some tire lube around the rim and levered the tire on both beads at same time. The tire went on fairly easy. I added about 20#s of air and the side walls spread out and the beads seated. When I added more air something popped and it leaked out the stem hole in the fellie. Took it apart and the stem had popped out of the tube. Not stuck in the tube --out of it.
I don't want to try putting the stem back in the hole. This is a different situation than a rubber stem being replaced with a metal stem. This was a new metal stemmed tube. I'm just wondering if I did something the wrong way,since its my first time using metal stemmed tubes.
No it's the same thing. Or;
You are missing the point, the flap is not installed as part of the valve install. The flap goes outside the bridge not under it.
Ray, as mark and Peter pointed out, the metal stem fits the tube, as installed during manufacture. You do not need to interfere with the nut and bridge washer. The tube is fitted into the tyre and inflated just enough to hold its shape. Then, if you must use one, the flap is installed after the tube is in the tyre.
Personally, I never use flaps. I use a rim liner on the rim instead. Your mis-fitting of a flap is just another way they can give grief. Others will disagree, preferring to spend many dollars as insurance against pinching the tube when fitting.
Hope you get it sorted soon.
Allan from down under.
Ray - Are you by chance referring to a new tube that had a new metal stem that had been manufactured with a silver dollar sized rubber base that was then vulcanized onto the tube? If so, it may be that the vulcanizing process was defective. Possibly the tube had not been cleaned and scuffed by the individual that affixed the new stem and rubber base assembly to the tube.
If the above facts describer your situation, I suggest you consult with the company from which you purchased the tube.
This is my tube. The base of the stem is only 11/16 diam. The bridge washer has no ridge rings (?) that would help clamp down on the tube
When I got the new tube it did not come with a bridge washer and nut, as I assume an original tube might have. I saw another posting on flaps and it showed the flap being against the tube and with the bridge washer tightened down on it, and this seemed to make sense to me rather than the other way. So maybe the flap should not be under the washer?
"So maybe the flap should not be under the washer?"
(with thanks to Mark G. for posting the link)
Ray, it appears the hole in your tube is too large. Do it like the link says, and you shouldn't have a problem.
Ray, The whole also looks to be at a 45 degree angle rather then flat with the surface of the tube.
The stem you have was manufactured with the silver dollar sized rubber base or foot moulded to the stem. The rubber base was then vulcanized to the tube.
It appears that you pulled the stem free of it's rubber foot when you tightened the bridge washer and nut WITH THE FLAP in between. There is nothing that can be done with the parts you have other than find some other use for the rubber.
Start over again with a new tube and do not insert the flap until the bridge washer and nut assembly are tight and the tube has been placed in the tire.
Does anyone NOT use bridge washers with the new metal stem tubes?
My dad doesn't use bridge washers. His opinion is that they are not needed with a vulcanized metal stem tube. He hasn't had any problems yet.
According to my 1917 edition of the Dyke's Manual, there is a washer that goes between the tube and the bridge washer. This would be a non-vulcanized stem - see below. This round washer was probably eliminated with the advent of the embossed bridge washer like the one shown below.
I suspect that there is generally no need for the bridge washer and nut when using the newer vulcanized metal stem.
The bridge washer serves two purposes. First it provides a surface to seal the old style valve stem in the tube. And the ears prevent the stem from twist when used in drop center rims like those found on a second generation Model A Ford.
When I earlier this summer replaced the tires and tubes on both my 1909 T, and 1907 K, I installed new tubes with the vulcanized stems. Since the tubes arrived directly from the tire vendor (Universal) with the bridge washer and nut in place, I left them there believing that while they may serve no purpose, they are unlikely to cause any harm. Thus far, such has been the case.
It is not totally clear from the picture, but I think the tube is probably still OK and could be used with an original-type stem. The original-type stem has a much larger base and a bridge washer that matches up with it such that it clamps properly. I would also smooth the top surface of the tube some more for a better seal.
However, it does look like that tube doesn't have as much rubber in the area of the stem as those rubber stem tube versions that I've put metal stems in.
Can you fellows still buy stick-on valve stems? We can still get 3-4" long thin rubber stemmed valves which stick on just like a puncture patch. I use them to save good Butyl rubber tubes which are much better quality than those available new. The valves are not widely stocked, but can be ordered in. They are good when you loose a valve stem through under inflation and the tyre moving on the rim and cutting the stem off.
These I hide in period Dill brand valve caps which completely the stem.
Just for interest.
Allan from down under.