RoadBikeReview.com's Forum Archives - Components


Archive Home >> Components(1 2 3 4 5 6 7 8 9 10 )


Now I'm having problems with tubes?(14 posts)

Now I'm having problems with tubes?tahoskier
Sep 4, 2002 12:02 PM
I recently posted a topic about flatting and tires. I switched out my tires with more durable ones. Everything was fine for awhile. Now I am getting punctures at the base of the inner tube valves. It has happened on the last three inner tubes. I have noticed that it only punctures or tears after I inflate the tire a few times(after a few rides). Could it be that it is pinching between the the valve stem and the stem hole when there is high pressure in the tire. Or did I buy a bad batch of tubes? (I purchase six tubes at the same time.) Or could I be installing the tube incorrectly.

Any advice for this newbie would be greatly appreciated.
re: Now I'm having problems with tubes?tahoskier
Sep 4, 2002 12:04 PM
I forgot to mention that I am using Spinergy x-aero wheels. If that makes a difference.
I'm thinking it's youretro
Sep 4, 2002 12:11 PM
Are you using a frame pump or floor pump? With a frame pump (but it happens with floor pumps, too), it's easy to shove it back and forth as you pump and rip out that valve stem. If that's the case, try bracing your non-pumping hand against the spokes or rim to hold the head end of the pump motionless.
Yuppergrzy
Sep 4, 2002 4:25 PM
Wriggle that sucka around and you'll yank it right off every time. Get a decent floor pump and treat your valve stems with care and respect.
I'm thinking it's youtahoskier
Sep 5, 2002 8:24 AM
Thanks. I'll try to be more careful.
There's this tooSpoke Wrench
Sep 4, 2002 12:59 PM
You really don't want your valve stem completely seated against the rim until AFTER the tire bead gets seated. Otherwise as you pressurize the tire, the tire bead will pinch the tube at the base of the valve stem.
Me toospookyload
Sep 4, 2002 3:29 PM
I buy tubes by the case and recently bought a case of Kenda Ultra Light tubes with 48mm valves. 7 of the 10 tubes tore the valve stems out after installation. This is during inflation, not when pulling the pump head off. The wheels are Mavic Ksyriums. Kenda sent me a new case when I emailed them. They have seemed fine. Salsa tubes are made by Kenda too by the way...so if they are either of these you might look into it.
Me tootahoskier
Sep 5, 2002 8:27 AM
They're Ultracycle(cheap tubes). I'll try another brand.

Thanks
In addition, lose the "valve nut"Kerry
Sep 4, 2002 4:40 PM
Lots of people screw that silly nut on the valve stem "to hold it in place while I pump" and as a result put a whole bunch of stress on the stem/tube interface. There is absolutely no need for that nut - the tube pressure keeps the valve stem in place. You don't mention what brand of tubes you're using, but people repeatedly have trouble with "off-brand" rubber.
In addition, lose the "valve nut"schills
Sep 6, 2002 8:50 AM
Keep the nut if you have a floor pump with one of those dual twist-to-lock type heads. I guarantee that the removal of that type of pump head puts a great deal of stress on the valve in a way that was never anticipated. The nut helps.
Please explainKerry
Sep 6, 2002 4:24 PM
When you are pulling off a pump head, the force on the valve stem is toward the hub, away from the rim. How does the nut do any good in this situation. Alternatively, if you're jerking the stem side to side (dumb move) then the nut doesn't help either. If there is no way to avoid such action with the pumps you refer to, then it's time for a new pump.
re: Now I'm having problems with tubes?maximum15
Sep 5, 2002 8:15 AM
Assuming that you are doing things correctly as other posters have mentioned, it is possible to have a bad group of tubes. I once purchased a few tubes, only to have everyone of them fail at the same location you are talking about. (I took them back to the LBS and argued until they replaced them). One other thing to look at is the area of your rim tape at the valve hole. Make sure you have coverage and no sharp bits from the rim hole creating a problem.
re: Defective TubesChen2
Sep 5, 2002 10:00 AM
I've seen more flats from defective tubes than flats from punctures. The tubes have been various brands and the valve stem area seems to be the most common area for defects.
~Al
Defective Operatorsgrzy
Sep 5, 2002 2:18 PM
Probably depends on where you buy your tubes. The stuff from Performance and other "bragain brands" is notorious for being total crap, but what you pay for is what you get. I have a fairly large bag of tubes that have been punctured, repaired and punctured many times over - and yet very few of them get tossed as defective tubes. If you buy quality tubes from Continental and others you will pay more, but then you never deal with the valve stem ripping out. the other thing is to use a quality floor pump as often as possible. Operator error is a large factor in the "defective valve stem" equation.