Advertise on Bikeforums.net



User Tag List

Page 1 of 2 12 LastLast
Results 1 to 25 of 28
  1. #1
    Let's do a Century jppe's Avatar
    Join Date
    Oct 2004
    Location
    North Carolina
    My Bikes
    Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace
    Posts
    6,164
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)

    Lesson for Newbies

    When a tire is not holding air, for gosh sakes don't just pump it up before you leave home and think you can sneak in a 35 mile ride on it. There's a good chance you won't even get ten miles before it goes flat-and almost causes your wheel to slide out from under you flipping you over.

    In fact it's actually more than a good chance. In my case it's 100%......

    You'd think we'd get a little smarter after riding a few years wouldn't you???? Maybe some of us non-newbs with a lazy streak could stand to learn a little something as well.

    Okay, okay-go ahead and learn the hard way..........

    BTW, the tire gave me everything it had to give. After close inspection I had a pretty huge chuck of rubber missing but the threads got me home....

  2. #2
    Squirrel solveg's Avatar
    Join Date
    Jun 2007
    Location
    Twin Cities, MN
    My Bikes
    07 Rivendell Atlantis, 80's Mondonico, 91 Cinelli ATB, 83 Schwinn Peleton, 94 Scott Cheyenne, 97 Klein Stage Comp, 81 SR Touring Bike, 80's CCM, 84 Bridgestone 200
    Posts
    4,917
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    How do you know it's not holding air? Seems like my tires lose 20 psi within a week.

  3. #3
    Senior Member
    Join Date
    Jun 2005
    Location
    rockford, il
    My Bikes
    Trek 7700, C'dale R2000
    Posts
    2,646
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The pavement is very rough in places where I bike. I use 700 x 23 tires on a Madone. Going down at over 30 MPH over a bump of a concrete bridge to black-top road gives quite a jolt.
    One day I forgot (got lazy) and did not pump up to 120 PSI.
    Result? Snake bite.
    Now I pump up faithfully and even got a new super pump.

  4. #4
    Senior Member snavebob's Avatar
    Join Date
    Jun 2007
    Location
    St Louis
    My Bikes
    Specialized Tricross SportCannondale Road Warrior 500, Trek 7300
    Posts
    125
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by solveg
    How do you know it's not holding air? Seems like my tires lose 20 psi within a week.
    I wonder why that is? Mine seem to do the same thing. Yet, I pump them up and they are fine for a 40 mile ride. Any ideas? Or, is it normal for them to lose air over time?

  5. #5
    Small Member maddmaxx's Avatar
    Join Date
    Nov 2003
    My Bikes
    Leader home built hardtail, Diamondback Response
    Posts
    7,126
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    Unlike car tires, you (probably) have tubes and they are relatively light so air leaks through the rubber at a very slow rate.

    There are things that are worse. For example it is reasonably difficult to contain hydrogen (a very small molecule) in many types of containers, it just slips through the walls and gets away. I wonder if this is why we can't make our bikes lighter by filling the tires with hydrogen or helium. Why is the sky blue. What am I doing up at this time of night?

  6. #6
    Banned. The Weak Link's Avatar
    Join Date
    Jan 2006
    Location
    Post-partisan Paradise
    My Bikes
    GF Wahoo '05, Trek T1000 '04, Lemond Buenos Aires '07
    Posts
    4,936
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by snavebob
    I wonder why that is? Mine seem to do the same thing. Yet, I pump them up and they are fine for a 40 mile ride. Any ideas? Or, is it normal for them to lose air over time?
    Yes. You need to check tire pressures before each and every ride.

    Unless you are feeling destructive and destroy your Presta valves in the process, in which case you were better off leaving them alone.

  7. #7
    Senior Member snavebob's Avatar
    Join Date
    Jun 2007
    Location
    St Louis
    My Bikes
    Specialized Tricross SportCannondale Road Warrior 500, Trek 7300
    Posts
    125
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by The Weak Link
    You need to check tire pressures before each and every ride.
    Thanks. I was checking them once a week.

  8. #8
    OnTheRoad or AtTheBeach stonecrd's Avatar
    Join Date
    Aug 2005
    Location
    Weston, FL
    My Bikes
    Ridley Noah RS, Scott CR1 Pro
    Posts
    2,170
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You will find that different tubes loose air at different rates. Just adjust your scheduled pumping accordingly. I check mine every 2-3 days and they loose about 20lbs in that period. However, every day I do a pinch check to make sure they are not soft. If soft then there is probably a leak. Sometimes slow leaks become fast leaks if you try to ride on them
    The problem with the gene pool is that there is no lifeguard and the shallow end is much too large

    2013 Noah RS

  9. #9
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    23,991
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jppe
    When a tire is not holding air, for gosh sakes don't just pump it up before you leave home and think you can sneak in a 35 mile ride on it.
    Actually, I did exactly that on Sunday on the tandem with my wife. We only rode 20 miles and it held air long enough for us to complete our ride but was pancake flat on Monday morning. At least I could fix it in the comfort of my home shop. I even patched the tube insted of sticking in a new one.

  10. #10
    Senior Member Thrifty1's Avatar
    Join Date
    Jun 2005
    Location
    OK
    Posts
    780
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by snavebob
    I wonder why that is? Mine seem to do the same thing. Yet, I pump them up and they are fine for a 40 mile ride. Any ideas? Or, is it normal for them to lose air over time?
    I use Michelin Air Stop tubes for that reason......they do lose air at a noticably slower rate but I still "top off" the pressure prior to each outing.

  11. #11
    Yen
    Yen is offline
    Surly Girly Yen's Avatar
    Join Date
    Mar 2007
    Location
    SoCal
    Posts
    4,105
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks for the tip! We check our tires now before every ride. We were checking only every few rides and were surprised how much air the tires had lost, and the big difference proper inflation makes during our rides.
    Specialized Roubaix Expert
    Surly Long Haul Trucker

  12. #12
    I need more cowbell. Digital Gee's Avatar
    Join Date
    Jun 2005
    Location
    Reno, Nevada
    My Bikes
    2012 Masi Evoluzione, 2009 Specialized Globe Vienna 2
    Posts
    7,894
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I top off my tires on Ruby Roubaix every couple of weeks. No problems so far. I can't imagine topping before every ride!
    Visit my blog! The Leadership Almanac
    2012 Masi Evoluzione
    2009 Specialized Globe Vienna 2

    Proud member of the original Club Tombay

  13. #13
    Squirrel solveg's Avatar
    Join Date
    Jun 2007
    Location
    Twin Cities, MN
    My Bikes
    07 Rivendell Atlantis, 80's Mondonico, 91 Cinelli ATB, 83 Schwinn Peleton, 94 Scott Cheyenne, 97 Klein Stage Comp, 81 SR Touring Bike, 80's CCM, 84 Bridgestone 200
    Posts
    4,917
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    DG, you use normal tubes, right?

    I think I've only seen a couple different brands. Why would DG's hold air better than anyone else's?

  14. #14
    I need more cowbell. Digital Gee's Avatar
    Join Date
    Jun 2005
    Location
    Reno, Nevada
    My Bikes
    2012 Masi Evoluzione, 2009 Specialized Globe Vienna 2
    Posts
    7,894
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by solveg
    DG, you use normal tubes, right?

    I think I've only seen a couple different brands. Why would DG's hold air better than anyone else's?
    Yep, normal tubes. Nothin' special.
    Visit my blog! The Leadership Almanac
    2012 Masi Evoluzione
    2009 Specialized Globe Vienna 2

    Proud member of the original Club Tombay

  15. #15
    OnTheRoad or AtTheBeach stonecrd's Avatar
    Join Date
    Aug 2005
    Location
    Weston, FL
    My Bikes
    Ridley Noah RS, Scott CR1 Pro
    Posts
    2,170
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    What pressure you run them at?

    If you are riding them at 110-120psi I would be surprised that they would not drop to 80-90psi over a couple of weeks. If you ride at lower pressure say 80-95psi then they will hold longer. It seems to me that they will stay at 80psi for month the higher pressures drop quicker.
    The problem with the gene pool is that there is no lifeguard and the shallow end is much too large

    2013 Noah RS

  16. #16
    Elite Rider Hermes's Avatar
    Join Date
    Oct 2006
    Location
    San Francisco Bay Area
    My Bikes
    Too Many
    Posts
    8,680
    Mentioned
    52 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Digital Gee
    I top off my tires on Ruby Roubaix every couple of weeks. No problems so far. I can't imagine topping before every ride!
    I top mine off prior to every ride. The primary reason is to reduce the chance of pinch flats. Riding at lower pressure is okay, improves the ride and traction especially on wet roads. However, if you hit a bump e.g. a raised section of road, you will pinch flat. Pinch flats are a function of tire pressure, rider weight and the speed at which you hit the bump.
    "Insanity: doing the same thing over and over again and expecting different results." Einstein

  17. #17
    I need more cowbell. Digital Gee's Avatar
    Join Date
    Jun 2005
    Location
    Reno, Nevada
    My Bikes
    2012 Masi Evoluzione, 2009 Specialized Globe Vienna 2
    Posts
    7,894
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by stonecrd
    What pressure you run them at?

    If you are riding them at 110-120psi I would be surprised that they would not drop to 80-90psi over a couple of weeks. If you ride at lower pressure say 80-95psi then they will hold longer. It seems to me that they will stay at 80psi for month the higher pressures drop quicker.
    I fill them to 100-110 when I top them off.
    Visit my blog! The Leadership Almanac
    2012 Masi Evoluzione
    2009 Specialized Globe Vienna 2

    Proud member of the original Club Tombay

  18. #18
    Elite Rider Hermes's Avatar
    Join Date
    Oct 2006
    Location
    San Francisco Bay Area
    My Bikes
    Too Many
    Posts
    8,680
    Mentioned
    52 Post(s)
    Tagged
    0 Thread(s)
    While we are on the topic of tire pressure and pressure over time, if you refill a tire with CO2 after fixing a flat, the CO2 will leak out faster than air. It is a good idea to deflate the tire to remove the CO2 and then refill with air.
    "Insanity: doing the same thing over and over again and expecting different results." Einstein

  19. #19
    Banned. The Weak Link's Avatar
    Join Date
    Jan 2006
    Location
    Post-partisan Paradise
    My Bikes
    GF Wahoo '05, Trek T1000 '04, Lemond Buenos Aires '07
    Posts
    4,936
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Hermes
    I top mine off prior to every ride. The primary reason is to reduce the chance of pinch flats. Riding at lower pressure is okay, improves the ride and traction especially on wet roads. However, if you hit a bump e.g. a raised section of road, you will pinch flat. Pinch flats are a function of tire pressure, rider weight and the speed at which you hit the bump.
    1. Do tires with lower pressures (80 vs. 120) ride slower?
    2. When I ride with knobbies at lower pressures they tend to feel sketchy. Just sayin'.
    3. "Large diameter tires have less rolling resistecne than narrower tires". True or false? Explain your answer.

  20. #20
    Time for a change. stapfam's Avatar
    Join Date
    Jan 2004
    Location
    6 miles inland from the coast of Sussex, in the South East of England
    My Bikes
    Dale MT2000. Bianchi FS920 Kona Explosif. Giant TCR C. Boreas Ignis. Pinarello Fp Uno.
    Posts
    19,915
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by The Weak Link
    1. Do tires with lower pressures (80 vs. 120) ride slower?
    2. When I ride with knobbies at lower pressures they tend to feel sketchy. Just sayin'.
    3. "Large diameter tires have less rolling resistecne than narrower tires". True or false? Explain your answer.
    Did one ride where I just jumped on the bike after feeling the tyres and that was a hard ride. Got back and only 80 psi.

    Knobblies - I ride a narrow 1.8 and keep them F & R at 50psi. Higher pressure will stop snakebites on the narrow tyre. Any less than that and I definitely squirm allover the road- but my Mud tyres are just spikes of Rubber. Doesn't matter how high I pump them up and anything over 15mph on tarmac and they are not under controll.

    Only ride 23's on the road but offroad- a wide tyre will cause me problems- Being a lightweight- I cannot push through the soft top surface to get grip. In Mud I skate across the surface wheras the narrow tyre will bit through the mud to the firm surface that is somewhere down there and I do get grip and as For riding across Grass- The Grass we have grabs hold of the tyre so the narrower the tyre, the less tyre to grab hold of.

    Now on the tandem- Anything less than a 2.1 at 60 psi and we are in trouble at the first bump we hit. Instant snakebite and we are biting the Gravel. On the road with slicks and it is 1.3's at 120 psi and we still have a flat spot at the bottom of the tyre in contact with the road. And that is on a tyre that is listed at max of 100 psi.
    How long was I in the army? Five foot seven.


    Spike Milligan

  21. #21
    OnTheRoad or AtTheBeach stonecrd's Avatar
    Join Date
    Aug 2005
    Location
    Weston, FL
    My Bikes
    Ridley Noah RS, Scott CR1 Pro
    Posts
    2,170
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I can't tell a lot of difference between 100 -120 psi but I certainly can tell the difference when they are <100psi. The bike just seems sluggish when the tires are under inflated.
    The problem with the gene pool is that there is no lifeguard and the shallow end is much too large

    2013 Noah RS

  22. #22
    Banned. The Weak Link's Avatar
    Join Date
    Jan 2006
    Location
    Post-partisan Paradise
    My Bikes
    GF Wahoo '05, Trek T1000 '04, Lemond Buenos Aires '07
    Posts
    4,936
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by stapfam
    Did one ride where I just jumped on the bike after feeling the tyres and that was a hard ride. Got back and only 80 psi.

    Knobblies - I ride a narrow 1.8 and keep them F & R at 50psi. Higher pressure will stop snakebites on the narrow tyre. Any less than that and I definitely squirm allover the road- but my Mud tyres are just spikes of Rubber. Doesn't matter how high I pump them up and anything over 15mph on tarmac and they are not under controll.

    Only ride 23's on the road but offroad- a wide tyre will cause me problems- Being a lightweight- I cannot push through the soft top surface to get grip. In Mud I skate across the surface wheras the narrow tyre will bit through the mud to the firm surface that is somewhere down there and I do get grip and as For riding across Grass- The Grass we have grabs hold of the tyre so the narrower the tyre, the less tyre to grab hold of.

    Now on the tandem- Anything less than a 2.1 at 60 psi and we are in trouble at the first bump we hit. Instant snakebite and we are biting the Gravel. On the road with slicks and it is 1.3's at 120 psi and we still have a flat spot at the bottom of the tyre in contact with the road. And that is on a tyre that is listed at max of 100 psi.
    Interesting. In this area many dirtheads ride on knobbies with 25-30 PSI. They claim they get better traction. If I run them that low I wash out on curves. I ride 2.1's at 40 PSI and that seems to work well. Maybe our trail conditions are a bit more forgiving -- trails are mostly hardpack and roots, many roots. Rocks tend to be sequestered in rock gardens, where they belong.

    Anyway, I've never had a pinch flat MTBing, but I did get one road cycling when I rode over a pothole, and I'm pretty sure I was running 110-120 PSI.

  23. #23
    Senior Member
    Join Date
    Jun 2005
    Location
    rockford, il
    My Bikes
    Trek 7700, C'dale R2000
    Posts
    2,646
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have never seen a 23 mm, 120 PSI tire holding full pressure over one day. They are always 10-20 PSI down.
    A 100 PSI ride over bumpy road is asking for trouble for this 185# guy.

  24. #24
    Small Member maddmaxx's Avatar
    Join Date
    Nov 2003
    My Bikes
    Leader home built hardtail, Diamondback Response
    Posts
    7,126
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by The Weak Link
    Interesting. In this area many dirtheads ride on knobbies with 25-30 PSI. They claim they get better traction. If I run them that low I wash out on curves. I ride 2.1's at 40 PSI and that seems to work well. Maybe our trail conditions are a bit more forgiving -- trails are mostly hardpack and roots, many roots. Rocks tend to be sequestered in rock gardens, where they belong.

    Anyway, I've never had a pinch flat MTBing, but I did get one road cycling when I rode over a pothole, and I'm pretty sure I was running 110-120 PSI.
    Depends on the terrain and the style of tire. Absorbing small bumps within the tire keeps the wheel in contact with the ground instead of bouncing up into the air. This however eats energy. Thus slower but perhaps better handling. Note the differences in style between Stapfam in Mud with more narrow and probably more pressure to knife down into the mud to solid ground underneath and my setup for dry gravel and small traprock which is a larger casing lower pressure tire that gets on top of the stuff and sort of floats along. Assuming equal engines (just for example, I know this will never happen), my setup would be slower and very slippery in his mud and his tires would probably get down into my loose gravel and slow down there.

    None of this is absolute, you have to try different things for each rider on each type of terrain.

    Note that one of the claimed advantages of tubeless tires is the ability to run lower pressures without flatting. There are however differences in casing desigh to get the tire to roll at these pressures.

  25. #25
    Let's do a Century jppe's Avatar
    Join Date
    Oct 2004
    Location
    North Carolina
    My Bikes
    Pinarello Prince/Campy SR; Cervelo R3/Sram Red; Trek 5900/Duraace, Cervelo P2C/Duraace
    Posts
    6,164
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I'm with Will and Hermes. I check air pressure before each ride and run 120 front and 130 rear. Never have issues with pinch flats here.....Even in a couple days the pressure in my tubes is down at least 20% so I can't imagine not pumping up for each ride.

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
  •