Advertise on Bikeforums.net



User Tag List

Page 1 of 2 12 LastLast
Results 1 to 25 of 31
  1. #1
    Senior Member
    Join Date
    Jul 2006
    Posts
    60
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    front tire constantly flat

    every time i go to ride my bike i find my front tire is flat. i've taken the tire off and there are no leaks in the tube and no punctures. i'll pump it back up and a few hours later it's flat again. the back tire is fine however. i keep my bike in my garage and it has been pretty cold lately so i wonder if that has something to do with it. i was hoping someone more knowledgable than me could provide some insight as to why this keeps happening.

  2. #2
    Senior Member Old Hammer Boy's Avatar
    Join Date
    Aug 2005
    Location
    Utah
    My Bikes
    Trek, Cannondale Tandem, Surly LHT
    Posts
    1,082
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Does your rim tape cover all of the spoke holes? If not, replace it. Try turning your tire inside-out and examine it under a strong light. Sometimes very small wires, thorns, glass, etc. can bury themself just under the inside layer and won't come out to do their mischief until you put some pressure on them. The other possibility is you may be pinch flatting the tube. That's squeezing the tube between the tire bead and the rim. If you're using the same tube and it still goes flat, fill it up partially and submurge it under water to find an "invisible" leak.

    Tires will lose some air over time, but usually only a few lbs./day, then stabalize and lose air more slowly. Generally, they'll hold perhaps 50% of their air for a month or two. How often do you ride?

  3. #3
    Senior Member Bill Kapaun's Avatar
    Join Date
    Feb 2007
    Location
    Mid Willamette Valley, Orygun
    My Bikes
    86 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.
    Posts
    7,174
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Have you checked to make sure the valve core is tight?

  4. #4
    Senior Member Old Hammer Boy's Avatar
    Join Date
    Aug 2005
    Location
    Utah
    My Bikes
    Trek, Cannondale Tandem, Surly LHT
    Posts
    1,082
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Bill Kapaun View Post
    Have you checked to make sure the valve core is tight?
    Thanks, I forgot that one!

  5. #5
    surly old man jgedwa's Avatar
    Join Date
    Sep 2006
    Location
    Carlisle, PA
    My Bikes
    IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
    Posts
    3,291
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Even if the valve core is tight, it could still be fouled with crud. Or Slime! You haven't been using Slime have you? Could be rust in there or could be dirt also. I used to work in a car tire place and we would put some spit on our fingers and them rub it over the end of the valve to get a film and then look for that film to bubble out. Not pretty, but it works.

    In addition to looking at the inside of the tire under a strong light, you could run your fingers slowly against the entire inside of the tire and feel for a sharp point.

    Bike tubes do loose air normally. They are not like car tires that hold air for seemingly ever. Some faster than others.

    Also, I have had many, many tubes that came from the factory with slight leaks at the seams.

    The definitive test for a tube is the old dunk test. If there is a leak, valve or tube itself, it will find it.

    jim
    Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
    --------------------------
    SB forever

  6. #6
    Senior Member
    Join Date
    Jul 2006
    Posts
    60
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    there shouldn't be any punctures because i have tire liners. i used to use slime but i don't any more and i haven't put any in these tires. i may have to try putting it in water, that's not something i would have thought of.

  7. #7
    Senior Member Bill Kapaun's Avatar
    Join Date
    Feb 2007
    Location
    Mid Willamette Valley, Orygun
    My Bikes
    86 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.
    Posts
    7,174
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    The "old bathtub" is the first place I go to check for small leaks!

  8. #8
    Has opinion, will express
    Join Date
    Jun 2003
    Posts
    12,996
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Large saucepan. Dunk the valve, too. Often missed. Check particularly where the join in your tyre liner is. Could be an abraded section of the tube from the sharp edges of the liner moving ever so slightly as the tyre rotates. This actually would be my bet.
    Dream. Dare. Do.

  9. #9
    Senior Member Tapeworm21's Avatar
    Join Date
    Jan 2007
    Location
    Berkeley
    My Bikes
    2010 Tarmac SL, 2007 Specialized Langster, 2013 Fairdale Weekender, 2013 Fairdale Coaster, 1986 Bridgestone 600, 1972 Schwinn Heavy Duty, 2014 Surley Long Haul Trucker
    Posts
    2,257
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Dude, just get a new tube. They're $5.
    2009 Specialized Tarmac Pro SL SRAM
    http://uplandsg.com/images/prodlogo_capoformaS.gif

  10. #10
    surly old man jgedwa's Avatar
    Join Date
    Sep 2006
    Location
    Carlisle, PA
    My Bikes
    IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
    Posts
    3,291
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I would consider it 3.95 well spent also, but lets not make that judgment for the OP. I applaud anyone's effort to save a penny and stick it to the man. It makes no economic sense, but some things are not about that. Particularly when it comes to bikes.

    jim
    Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
    --------------------------
    SB forever

  11. #11
    Senior Member donheff's Avatar
    Join Date
    Jun 2007
    Location
    Capitol Hill, Washington, DC
    My Bikes
    Specialized Tricross Comp
    Posts
    1,245
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Tapeworm21 View Post
    Dude, just get a new tube. They're $5.
    +10
    Every man is, or hopes to be, an Idler. -- Samuel Johnson

  12. #12
    Has opinion, will express
    Join Date
    Jun 2003
    Posts
    12,996
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You know, new tubes are OK, but if you don't know what's causing the original one to deflate, you're just wasting money putting a new one in. Duh!
    Dream. Dare. Do.

  13. #13
    The Improbable Bulk Little Darwin's Avatar
    Join Date
    Jul 2005
    Location
    Wilkes-Barre, PA
    My Bikes
    Many
    Posts
    7,383
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Plus thinking green, a patch is probably better than a tube.

    I usually toss my tubes, but I'm just saying...
    Slow Ride Cyclists of NEPA

    People do not seem to realize that their opinion of the world is also a confession of character.
    - Ralph Waldo Emerson

  14. #14
    Senior Member
    Join Date
    Jul 2006
    Posts
    60
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i have a spare tube so that's not a problem. the tire has actually retained the air i put in it a few days ago. i have no idea why it's so finnicky but it's working now.

  15. #15
    Senior Member BCRider's Avatar
    Join Date
    Mar 2008
    Location
    The 'Wack, BC, Canada
    My Bikes
    Norco (2), Miyata, Canondale, Soma, Redline
    Posts
    5,432
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yeah, good luck hearing or feeling a 2 hour leak. Dunking the tube to find the leak is the only way in those cases.

    If this is truly an intermittent leak then there's a very good chance it was caused by gunk in the valve. Do you use the valve caps all the time? I know that some think they are just there to avoid a valve stem puncture while the tube is in the box. But the caps also help by avoiding dirt getting on the end of the valve and blowing into the tube the next time you fill up the tire.
    Model airplanes are cool too!.....

  16. #16
    Senior Member Thumpic's Avatar
    Join Date
    Dec 2007
    Location
    The Sunny South
    Posts
    1,566
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    grit in the valve that finally blew into the tube....................
    Thumpic....

    Green is the new "CHEAP"

  17. #17
    Large Member urodacus's Avatar
    Join Date
    Nov 2006
    Location
    Okinawa
    My Bikes
    05 Giant TCR 0; 83 Colnago Saronni now Single speed; 81 San Rensho Katana Super Export track bike, #A116-56
    Posts
    1,173
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    not using latex tubes, are you? they leak air and are essentially flat overnight. much lighter in some cses and a smoother ride with less rolling resistance, but leaky. mine go from 120 to 20 psi in about 15 hours.

    most cheaper tubes are the butyl rubber type (geneally black in colour). these hold air much better, especially if the valve is properly inserted in the valve tube and ther's no grit around the seal.
    05 Giant TCR Composite; 83 Colnago Saronni; 81 San Rensho Katana Super Export track #A116-56; 89 Zunow Pentaglia: SOLD; 85 Tommasini: SOLD; 83 Guerciotti: SOLD

  18. #18
    Miles over Matter spoke50's Avatar
    Join Date
    Mar 2008
    Location
    birmingham al
    My Bikes
    trek
    Posts
    387
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I was thinking of starting this same thread until stumbled into this one. I'm having this exact problem except I am on my third tube in a month and still flat. I have examined the inside of the tire and can't seem to find anything. I'm now to the point of buying another tire. The one I got will hold air long enough to get a short ride in, but I just don't feel comfortable on it. The tire about 1000 miles on it (Continental Attack) any idea how many miles you should get out of a set of tires like these?

  19. #19
    Senior Member Pig_Chaser's Avatar
    Join Date
    Sep 2007
    Location
    Edmonton, AB
    My Bikes
    '07 Giant OCR3
    Posts
    1,144
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I suspect something in your tire.

    I had a situation where my front tire went flat twice in two days. Now i know how to fix a flat and I ran my fingers along the inside of the tire after the first flat and found nothing, so i fixed the flat and off i went. After the second flat in as many days, again i felt the inside of the tire and found nothing. However my suspisions told me something was wrong since it wasn't a pinch flat and the hole was on the onside of the tube where it makes contact with the tire. This time i scrutinized the tire in the location of the hole by flexing it and sure enough i found a small piece of glass that was actually imbedded in the tire.

    The moral of the story: Line up your tire label with your stem so that you can scrutinize your tire in the area of the leak.

  20. #20
    Mad bike riding scientist cyccommute's Avatar
    Join Date
    Nov 2004
    Location
    Denver, CO
    My Bikes
    Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
    Posts
    15,768
    Mentioned
    18 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Pig_Chaser View Post
    I suspect something in your tire.

    I had a situation where my front tire went flat twice in two days. Now i know how to fix a flat and I ran my fingers along the inside of the tire after the first flat and found nothing, so i fixed the flat and off i went. After the second flat in as many days, again i felt the inside of the tire and found nothing. However my suspisions told me something was wrong since it wasn't a pinch flat and the hole was on the onside of the tube where it makes contact with the tire. This time i scrutinized the tire in the location of the hole by flexing it and sure enough i found a small piece of glass that was actually imbedded in the tire.

    The moral of the story: Line up your tire label with your stem so that you can scrutinize your tire in the area of the leak.
    Also mark you tube with a permanent marker so that you put the tube in the same orientation when you put the tire back together. This is particularly handy for those slow leakers. If you end up with more then one patch in the same place, look for the poker

    I pump my tubes up so that they are about double the size (cross section diameter) of normal and then dunk them to find the leak. If it a slow leaker, you may have to move very slowly and knock the bubbles that normally form on the tube off to see if any new ones form.
    Stuart Black
    Solo Without Pie. The search for pie in the Midwest.
    Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
    Days of Wineless Roads. Bed and Breakfasting along the KATY
    Twisting Down the Alley. Misadventures in tornado alley.
    An Good Ol' Fashion Appalachian Butt Whoopin'.

  21. #21
    Small Member maddmaxx's Avatar
    Join Date
    Nov 2003
    My Bikes
    Leader home built hardtail, Diamondback Response
    Posts
    7,126
    Mentioned
    5 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by lason View Post
    every time i go to ride my bike i find my front tire is flat. i've taken the tire off and there are no leaks in the tube and no punctures. i'll pump it back up and a few hours later it's flat again. the back tire is fine however. i keep my bike in my garage and it has been pretty cold lately so i wonder if that has something to do with it. i was hoping someone more knowledgable than me could provide some insight as to why this keeps happening.
    You find no leaks or punctures. (I'll assume that you are checking under water) You did not say if you rode the bicycle before it went flat again. If you did, then a surprisingly common failure mode is failure to screw the nut back down on a presta valve. Normal riding will cause the valve to unseat (vibration etc) often enough to bleed air. Other than that, bad stem/valves cause as many slow leaks as holes in the tube.

  22. #22
    Senior Member
    Join Date
    Jul 2006
    Posts
    60
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    well, i found the leak. it was the valve that was slowly leaking. the tire wasn't punctured at all. it wasn't until i changed the tire that i found that the other one was leaking. i tried dunking it in the tub but i didn't see any bubbles. it wasn't until i hung the tire over the shower pole that i heard air hissing out. i tried pumping it up to see if i could pinpoint the leak and that's when i found it. thanks everyone for your input. i thought i had a phantom leak! i wonder what could have caused it. anyway, hopefully the new tire will last a while (at least until the weather picks up so i can go out riding)

  23. #23
    Uber Goober StephenH's Avatar
    Join Date
    Sep 2007
    Location
    Dallas area, Texas
    Posts
    10,614
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    On a Schrader valve, there is a little removable insert that can be taken out, and it can be loose. You can also get crud in there that keeps it from closing right. (We used to remove the insert to deflate truck tires, much quicker that way- and will actually form frost on the valve stem while deflating).
    "be careful this rando stuff is addictive and dan's the 'pusher'."

  24. #24
    Senior Member
    Join Date
    Jul 2006
    Posts
    60
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    nevermind, i found a slight tear in the tire that was next to the valve. that's what was causing the leak.

  25. #25
    Senior Member coldfeet's Avatar
    Join Date
    Dec 2007
    Posts
    2,118
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Pig_Chaser View Post
    I suspect something in your tire.

    I had a situation where my front tire went flat twice in two days. Now i know how to fix a flat and I ran my fingers along the inside of the tire after the first flat and found nothing, so i fixed the flat and off i went. After the second flat in as many days, again i felt the inside of the tire and found nothing. However my suspisions told me something was wrong since it wasn't a pinch flat and the hole was on the onside of the tube where it makes contact with the tire. This time i scrutinized the tire in the location of the hole by flexing it and sure enough i found a small piece of glass that was actually imbedded in the tire.

    The moral of the story: Line up your tire label with your stem so that you can scrutinize your tire in the area of the leak.
    There was a thread on here about the guy that ran his fingers round the tire to find the problem and found it was
    broken off syringe needle! Good idea to look first, or use a rag.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •