Tubes Air thieves

Discussion in 'Bicycle Repair' started by darwin, Jul 22, 2008.

  1. darwin

    darwin Well-Known Member

    Ive owned vehicles all my life and never had to put air in tires on a weekly basis. What is up with bicycle tires n tubes nowadays? Ive done the spit test on the valve stems and both front and back dont leak. Mysteriously though every weekend my tires lose 30 psi, Im scratching my head and its a pain in the arse. Do I need to do an air dance or pray to the tire gods or what?.............Someone is stealing my AIR!

  2. ihatemybike

    ihatemybike Member

    Time to pull the tubes and put them under water. Bet there are really small punctures or really slow valve stem leaks.

    I've found that pulling the valve stem core, putting some rubber cement it and re-installing will cure valve stem leak.
  3. Mountainman

    Mountainman Active Member

    I wonder what bicycle shops have to say about -- airing up ??? I owned a bicycle shop -- many, many years ago -- 1970-1973... If I remember right - after putting a new bicycle together -- filling the tires to max -- they seemed to hold air -- enough to ride anyway -- for some time -- couple of months -- but when sold needed to be topped off -- with some air.. My MB (mountainbike) with regular factory tubes -- seems to stay up (air) for around 2 to 3 weeks before needing more air.. Feel like I am blowing hot air here.. PS - if we are losing 30 lbs of air in one week we should -- check for leaks - or - buy new tubes.. Happy Riding from - Mountainman
  4. ihatemybike

    ihatemybike Member

    It is true that compared to a car's tire bicycle tires will lose air faster. This is due to the higher pressures and the thinner rubber being more porous.
  5. az cra-z

    az cra-z Guest

    I found that after switching to thorn-resistant (thicker) tubes, I go much longer between "air-ups", months vs. weeks with standard tubes.
  6. Butch

    Butch Guest

    On my bikes the tubes with SLIME in them hold air quite a while longer than the tubes without the SLIME.
  7. KilroyCD

    KilroyCD Active Member

    I'm with az cra-z on this one. Try the thorn proof tubes if you aren't using them already. The thicker (at least twice as thick) rubber will be less porous and hold air longer. Not only that, they're much more durable. I switched to these on my Whizzer after 2 flat tires in one month.
  8. sparky

    sparky Active Member

    Any specific rubber cement you prefer??

    This is the only thing left on my tire setup I worry about failing...
  9. turkeyssr

    turkeyssr Guest

    Well, some of the variation could be due to temperature, though I wouldn't think by 30psi. I find in my 'regular' bike, that I air up to 130psi in the rear and 100psi in the front, they lose about 10psi or so in a week. I would look into thorn resistant tires as another suggested, maybe even slime. -- John
  10. BeachBum

    BeachBum New Member

    If your ride is outside there is also the posibility of a jerk with a lolipop stick deflating you. :(

    Got any neighbors who might be mad for some reason?
  11. Mountainman

    Mountainman Active Member

    sparky -- Be careful with this one -- never heard of putting rubber cement on or in a valve stem ??? I am sure it would seal once - but - after that it may be - shot out ! Happy riding from - Mountainman
    Last edited: Jul 27, 2008
  12. mark2yahu

    mark2yahu Member

    The thorn-proof inner tubes will stay at rated psi much longer, like 2 to 3 months. The Slime Smart tubes are similar.

    Because I hate getting flats, I bought one of those Air Free Tires for my rear wheel. Their claims are true, it does ride-feel like a conventional pneumatic tire. Very expensive, though.
  13. sparky

    sparky Active Member

    Seems like I'm still losing more than 5psi a week with the thorn-proof tubes. Don't care, I've always known that bike tubes leak a lot.

    I would love to ride on a set of those to see how thye handle.
  14. Scottm

    Scottm Guest

    All the kids in the neighborhood come to me to fill their tires or fix flats on their wal mart bikes. After submerging several tubes in water I see tiny pin hole leaks at the seams and never around the stems. No nails or thorns, just factory carp. It's funny, some tires will hold air for weeks and then won't hold air for a day. I try to replace them with above mentioned thorn proof tubes. I also save the old tubes, cut the stems off and slice them open. Then I stick the new tube in the old tube, then put it in the tire. Don't know if it helps as an extra liner or if I just like to think it does.
  15. sparky

    sparky Active Member

    Using old tubes as tire liners is definitely worth it. Ya just gotta have some old ones first...

    As for the leaking from the stems, I've never experienced this myself. But every time I air up my tubes, I see tiny cracks around the valve stems... and I know when I do eventually get a flat, it's going to because the cracks in the valve stem kept getting bigger and bigger.
  16. mark2yahu

    mark2yahu Member

    Hi Sparky; I bought just one Airfree tire to see how they ride. Like I said, it rides like a regular tire. For me, it handles like a "real" tire. The only difference is if you pick the bike up about an inch or two and drop it, it will only bounce a little and absorb the shock, compared to a pneumatic tire which will bounce pretty good and also absorb shock. Next payday I'm ordering the 2nd tire for the front wheel :) It's worth it...I go to the desert and out there, you can't afford to get flats.
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