Tire Pressure and Stability

Discussion in 'Road Cycling' started by Elisa Francesca, Jun 20, 2003.

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  1. Increasingly concerned about the slow response time of my bicycle brakes and after nearly ramming
    into a parked car, I took Myrtille to the Local Bicycle Shop for a general check-up. My problem is
    my inexperience. She is my first ever bike, I only started riding a few months ago, and I never know
    whether my discomfort is due to a bike fault or my bad riding.

    The young man at the shop did indeed report a problem with the brakes. They were not worn out but
    completely misregulated - he said I was heading straight into a wall. He checked the derailleur too,
    finding it slightly misaligned. I have been able to change gear without too much hassle but about
    one time in twenty the chain pops off. Most interestingly, he said the tires were very flat, and
    pumped them up to the usually required pressure.

    To my delight, I found Myrtille far more stable on the road today than I have ever known her. I have
    been reporting my sense of instability at higher speeds in another thread, which has given rise to a
    very impressive debate about the physics of gyroscopes, as one knight after another enters the joust
    to prove that my perception is against the laws of the Created Universe. Well, it turns out there
    was a whole other parameter in the picture - flaccid tires wobbling all over the place, the faster
    the wobblier.

    Obvious to you, but not to me. There's a first time to everything. Many years ago, knowing nothing
    about photography, I bought an Olympus SLR which should have been the camera of my lifetime. I
    couldn't get a single decent picture out of it, but of course that was just because I was stupid. I
    only cottoned on to the fact that the instrument itself was a total lemon, with a shutter that
    answered to no-one, when it was past guarantee and cost a fortune to repair. Newbies don't know
    enough to know when they re in the right.

    There's something else I have learned: An instrument is not necessarily in good use-condition
    just because it is brand new and shiny. Bikes in cycling shops are like animals in pet shops -
    unloved, treated only as well as is minimally consistent with their economic status as a
    commodity, they wait forlornly for a human to adopt them and complete their destiny. I suppose an
    experienced cyclist with a new bike spends the whole first day checking it over and regulating
    everything, just as a computer nerdess like myself will spend a good week on the installation and
    tweaking of a new machine. But newbies should be aware, especially if they buy their cycles in
    places of mass consumption like mall shops (as opposed to small cycling businesses run by
    passionately committed experts) that they will need to line up a knowledgeable person to help
    them get their bike on the road.

    My two centimes. Cheers,

    Elisa Roselli Paris, France
     
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  2. On Fri, 20 Jun 2003 10:12:09 +0200, Elisa Francesca Roselli
    <[email protected]> wrote:

    >To my delight, I found Myrtille far more stable on the road today than I have ever known her. I
    >have been reporting my sense of instability at higher speeds in another thread, which has given
    >rise to a very impressive debate about the physics of gyroscopes, as one knight after another
    >enters the joust to prove that my perception is against the laws of the Created Universe. Well, it
    >turns out there was a whole other parameter in the picture - flaccid tires wobbling all over the
    >place, the faster the wobblier.

    They do that. And even at low speeds, cornering will be hell.

    Unlike cars, bike tires *really* need to be regularly (ie, you can usually get away with at very
    most a couple of weeks between, depending on use, usually less) pumped up. If you don't have a pump,
    you should consider buying one. For the wide type of tire, 35-40 mm wide, that you probably have,
    the 'rule of thumb' is that you should pump it until you can just barely indent it by pressing your
    thumb against it. If you get a pump with a pressure indicator, you can inflate them more accurately
    to a set standard, but it's not absolutely necessary.

    Jasper
     
  3. Archer

    Archer Guest

    In article <[email protected]>,
    [email protected] says...

    ...

    > To my delight, I found Myrtille far more stable on the road today than I have ever known her. I
    > have been reporting my sense of instability at higher speeds in another thread, which has given
    > rise to a very impressive debate about the physics of gyroscopes, as one knight after another
    > enters the joust to prove that my perception is against the laws of the Created Universe. Well, it
    > turns out there was a whole other parameter in the picture - flaccid tires wobbling all over the
    > place, the faster the wobblier.

    Maybe now you'll feel comfortable screaming down those hills you were worried about in a
    previous message!

    > Obvious to you, but not to me. There's a first time to everything. Many years ago, knowing nothing
    > about photography, I bought an Olympus SLR which should have been the camera of my lifetime. I
    > couldn't get a single decent picture out of it, but of course that was just because I was stupid.
    > I only cottoned on to the fact that the instrument itself was a total lemon, with a shutter that
    > answered to no-one, when it was past guarantee and cost a fortune to repair. Newbies don't know
    > enough to know when they re in the right.

    Good point.

    > There's something else I have learned: An instrument is not necessarily in good use-condition just
    > because it is brand new and shiny. Bikes in cycling shops are like animals in pet shops - unloved,
    > treated only as well as is minimally consistent with their economic status as a commodity, they
    > wait forlornly for a human to adopt them and complete their destiny.

    I like this analogy!

    > I suppose an experienced cyclist with a new bike spends the whole first day checking it over and
    > regulating everything, just as

    That's me!

    > a computer nerdess like myself will spend a good week on the installation and tweaking of a new
    > machine.

    That's me, too!

    > But newbies should be aware, especially if they buy their cycles in places of mass consumption
    > like mall shops (as opposed to small cycling businesses run by passionately committed experts)
    > that they will need to line up a knowledgeable person to help them get their bike on the road.
    >
    > My two centimes. Cheers,

    This post is definitely worth more than two centimes! At least a few Euro's, I'd say.

    --
    David Kerber An optimist says "Good morning, Lord." While a pessimist says "Good Lord,
    it's morning".

    Remove the ns_ from the address before e-mailing.
     
  4. Mark Hickey

    Mark Hickey Guest

    <[email protected]> wrote:

    >Bikes in cycling shops are like animals in pet shops - unloved, treated only as well as is
    >minimally consistent with their economic status as a commodity, they wait forlornly for a human to
    >adopt them and complete their destiny. I suppose an experienced cyclist with a new bike spends the
    >whole first day checking it over and regulating everything, just as a computer nerdess like myself
    >will spend a good week on the installation and tweaking of a new machine.

    Eeeek, if that's true, I'm likely to be arrested by the cycling equivalent of the ASPCA (American
    Society for the Prevention of Cruelty to Animals). I tend to ride my bikes hard, and put them away
    dirty. I lube the chain whenever it's annoyingly noisy, and clean the bike - well, sometimes before
    a race. To me, the dust that accumulates on my bikes is like a fine patina of use - akin to the mud
    you might find hanging from every available perch on a four wheel drive vehicle that's used
    properly. I raise my nose to those spotlessly shiny bikes I see on the road and label their riders
    "poseurs" (did I spell that right?). ;-)

    Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
     
  5. Dane Jackson

    Dane Jackson Guest

    Mark Hickey <[email protected]> wrote:
    >
    > Eeeek, if that's true, I'm likely to be arrested by the cycling equivalent of the ASPCA (American
    > Society for the Prevention of Cruelty to Animals). I tend to ride my bikes hard, and put them away
    > dirty. I lube the chain whenever it's annoyingly noisy, and clean the bike - well, sometimes
    > before a race. To me, the dust that accumulates on my bikes is like a fine patina of use - akin to
    > the mud you might find hanging from every available perch on a four wheel drive vehicle that's
    > used properly. I raise my nose to those spotlessly shiny bikes I see on the road and label their
    > riders "poseurs" (did I spell that right?). ;-)

    Ha! I'm tempted to forward your post to my tri-athlete director. She gave me a (moderately) hard
    time about my bike being dirty. Cripes, it's Seattle and I ride every day to work rain or shine. Of
    course my bike is covered with road spray, I'm always using it.

    --
    Dane Jackson - z u v e m b i @ u n i x b i g o t s . o r g clone, n:
    1. An exact duplicate, as in "our product is a clone of their product." 2. A shoddy,
    spurious copy, as in "their product is a clone of our product."
     
  6. Mark Hickey

    Mark Hickey Guest

    Dane Jackson <[email protected]> wrote:

    >Mark Hickey <[email protected]> wrote:
    >>
    >> Eeeek, if that's true, I'm likely to be arrested by the cycling equivalent of the ASPCA (American
    >> Society for the Prevention of Cruelty to Animals). I tend to ride my bikes hard, and put them
    >> away dirty. I lube the chain whenever it's annoyingly noisy, and clean the bike - well, sometimes
    >> before a race. To me, the dust that accumulates on my bikes is like a fine patina of use - akin
    >> to the mud you might find hanging from every available perch on a four wheel drive vehicle that's
    >> used properly. I raise my nose to those spotlessly shiny bikes I see on the road and label their
    >> riders "poseurs" (did I spell that right?). ;-)
    >
    >Ha! I'm tempted to forward your post to my tri-athlete director. She gave me a (moderately) hard
    >time about my bike being dirty. Cripes, it's Seattle and I ride every day to work rain or shine. Of
    >course my bike is covered with road spray, I'm always using it.

    A dirty bike is a used bike. A sparkling clean bike is a garage ornament. ;-)

    Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
     
  7. Buck

    Buck Guest

    "Mark Hickey" <[email protected]> wrote in message
    news:[email protected]...
    > Dane Jackson <[email protected]> wrote:
    > >Ha! I'm tempted to forward your post to my tri-athlete director. She gave me a (moderately) hard
    > >time about my bike being dirty. Cripes, it's Seattle and I ride every day to work rain or shine.
    > >Of course my bike is covered with road spray, I'm always using it.
    >
    > A dirty bike is a used bike. A sparkling clean bike is a garage ornament. ;-)

    But a filthy bike needs either a bath or fenders.

    -Buck
     
  8. Elisa Francesca Roselli wrote:
    > Most interestingly, he said the tires were very flat, and pumped them up to the usually required
    > pressure.
    >
    > To my delight, I found Myrtille far more stable on the road today than I have ever known her. I
    > have been reporting my sense of instability at higher speeds in another thread, [...] Well, it
    > turns out there was a whole other parameter in the picture - flaccid tires wobbling all over the
    > place, the faster the wobblier.

    I am embarased to admit that it didn't occur to me that your feeling of instability was more than
    just a feeling--that it actually was physical instability that could be caused by tire inflation. I
    should have thought of this. Come to think of it, untrue wheels or a messed up headset can also
    cause instability though those are less common in new bikes. Tires need to be re-inflated regularly.
    Rubber is gas permeable; especially the relatively thin rubber of bike tubes. Another problem with
    under-inflated tires is that you can hit a bump in the road and the tire will be pressed violently
    against the wheel rim which can cut the tube; putting two good sized holes in the tube (often called
    a "snake bite" flat).

    Anytime your bike gets wobbly and you don't know why, take it to the bike shop and have them check
    it out. It should be stable; even at relatively high speeds.

    I'm glad to hear that the bike shop caught it and fixed it and educated you about proper tire
    inflation. It sounds like you'll be going down those hills a little faster soon.

    --Bill Davidson
     
  9. Dane Jackson

    Dane Jackson Guest

    Buck <j u n k m a i l @ g a l a x y c o r p . c o m> wrote:
    > "Mark Hickey" <[email protected]> wrote in message
    >>
    >> A dirty bike is a used bike. A sparkling clean bike is a garage ornament. ;-)
    >
    > But a filthy bike needs either a bath or fenders.

    I have a front fender (though I had to improvise a mount)[1]. But there is no way to put a regular
    fender in the rear. I would either have to settle for a partial fender, or finally get around to
    making one.

    The next bike is definitely going to be more of a touring frame.

    [1] I was *really* annoyed to see that this years edition of my bike has front fender eyelets. That
    would have saved me a trip or two to the hardware store.

    --
    Dane Jackson - z u v e m b i @ u n i x b i g o t s . o r g clone, n:
    2. An exact duplicate, as in "our product is a clone of their product." 2. A shoddy,
    spurious copy, as in "their product is a clone of our product."
     
  10. >Bikes in cycling shops are like animals in pet shops - unloved, treated only as well as is
    >minimally consistent with their economic status as a commodity, they wait forlornly for a human to
    >adopt them and complete their destiny.

    Nice sentiment. The fact is that they are only machines. To attribute emotion to a machine is only
    to project your own feelings, they are only constructs. You said it yourself, and I paraphrase,
    either the machine is well regulated or it isn't.

    We cyclists are intimate with our machines, and we understand issues of comfort level. But it isn't
    the machine doing it deliberately.

    It's either a less well-regulated machine or a user issue, the only thing worth considering is the
    interface, why do I call my PX-10 Colette and tolerate a broken front derailleur high limit screw,
    well, I'm not logical but I am consistent.

    And you can't get new parts for her, ah, it.

    I want to say it's a personality but in fact it's just a constellation of workarounds that I
    wouldn't tolerate in any of my other bikes.

    They each have other quirks, but they are just machines.

    --

    _______________________ALL AMIGA IN MY MIND_______________________ ------------------"Buddy Holly,
    the Texas Elvis"------------------
    __________306.350.357.38>>[email protected]__________
     
  11. Hunrobe

    Hunrobe Guest

    >Mark Hickey [email protected]

    wrote in part:

    >I raise my nose to those spotlessly shiny bikes I see on the road and label their riders "poseurs"
    >(did I spell that right?). ;-)

    I clean my road bike regularly, some might say obsessively. What's so obsessive about using
    different sized toothbrushes for the derailleurs versus the calipers? ;-) BTW, does your observation
    apply if the bike in question happens to be a Habanero?

    Regards, Bob Hunt
     
  12. Mark Hickey

    Mark Hickey Guest

    [email protected] (Hunrobe) wrote:

    >>Mark Hickey [email protected]
    >
    >wrote in part:
    >
    >>I raise my nose to those spotlessly shiny bikes I see on the road and label their riders "poseurs"
    >>(did I spell that right?). ;-)
    >
    >I clean my road bike regularly, some might say obsessively. What's so obsessive about using
    >different sized toothbrushes for the derailleurs versus the calipers? ;-) BTW, does your
    >observation apply if the bike in question happens to be a Habanero?

    No, THAT'S different.

    Just make sure and keep the decals clean.

    Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
     
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