Roadie tire sizes...

Discussion in 'Mountain Bikes' started by Alex Ravenel, Mar 7, 2003.

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  1. Alex Ravenel

    Alex Ravenel Guest

    Forgive me!

    I have an old roadie in the basement I am rebuilding. Needs new tires. It has some pretty nice mavic
    rims on it, 27". Will a 700 tire or tube fit this?

    Thanks...

    --
    --------
    Alex Ravenel http://www.theravenel.net
     
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  2. Alex Ravenel wrote:
    >
    > Forgive me!
    >
    > I have an old roadie in the basement I am rebuilding. Needs new tires. It has some pretty nice
    > mavic rims on it, 27". Will a 700 tire or tube fit this?

    No.

    700c's are 29 inch wheels.

    Barry
     
  3. G.T.

    G.T. Guest

    B a r r y B u r k e J r . wrote:
    > Alex Ravenel wrote:
    >
    >>Forgive me!
    >>
    >>I have an old roadie in the basement I am rebuilding. Needs new tires. It has some pretty nice
    >>mavic rims on it, 27". Will a 700 tire or tube fit this?
    >
    >
    > No.
    >
    > 700c's are 29 inch wheels.
    >

    They're only called that because of some lame mtn bike marketeer, they were never called 29" until
    a marketeer came up with the label so the public wouldn't recall the last round of 700c wheeled
    mtn bikes. And just because some 700c mtn bike tires may be close to 29" in outer diameter doesn't
    mean all will.

    700c = 622 mm = 24.5" 27" = 630 mm = 24.8"

    So close but no banana. But nowhere near the diff between 27" and 29". Some road bikes can even use
    either rim if you have older long reach calipers with a lot of adjustment.

    Greg

    --
    "Destroy your safe and happy lives before it is too late, the battles we fought were long and hard,
    just not to be consumed by rock n' roll..." - The Mekons
     
  4. Ken

    Ken Guest

    Alex Ravenel <[email protected]> wrote in news:[email protected]:
    > I have an old roadie in the basement I am rebuilding. Needs new tires. It has some pretty nice
    > mavic rims on it, 27". Will a 700 tire or tube fit this?

    Tubes will fit, tires will not.
     
  5. Alex Ravenel

    Alex Ravenel Guest

    OK, what should I get width-wise? I dont want to go with an inch, a little narrow--should I go 1
    1/8 or 1 1/4?

    --
    --------
    Alex Ravenel http://www.theravenel.net
     
  6. Alex Ravenel

    Alex Ravenel Guest

    > Tubes will fit, tires will not.
    >

    Thats what I was thiking. Thanks much.

    --
    --------
    Alex Ravenel http://www.theravenel.net
     
  7. G.T.

    G.T. Guest

    Alex Ravenel wrote:
    > OK, what should I get width-wise? I dont want to go with an inch, a little narrow--should I go 1
    > 1/8 or 1 1/4?
    >

    I'd go with the 1 1/4. The only benefit of narrow tires is the ability to run 110 psi and up. At a
    given pressure fatter tires have less rolling resistance (due to less hysteresis).

    Greg

    --
    "Destroy your safe and happy lives before it is too late, the battles we fought were long and hard,
    just not to be consumed by rock n' roll..." - The Mekons
     
  8. Ken

    Ken Guest

    "G.T." <[email protected]> wrote in news:[email protected]:
    > I'd go with the 1 1/4. The only benefit of narrow tires is the ability to run 110 psi and up. At a
    > given pressure fatter tires have less rolling resistance (due to less hysteresis).

    While that partially is true, it is not a valid argument. If two tires have identical construction,
    except that one is wider, you should *not* run them at the same pressure. The narrower tire will
    have a higher optimal pressure and thus a lower rolling resistance. The wider tire will weigh more
    and roll slower, but give you a plusher ride, especially on rough roads.

    Ken
     
  9. G.T.

    G.T. Guest

    Ken wrote:
    > "G.T." <[email protected]> wrote in news:[email protected]y.com:
    >
    >>I'd go with the 1 1/4. The only benefit of narrow tires is the ability to run 110 psi and up. At a
    >>given pressure fatter tires have less rolling resistance (due to less hysteresis).
    >
    >
    > While that partially is true, it is not a valid argument. If two tires have identical
    > construction, except that one is wider, you should *not* run them at the same pressure.

    Why not? If the max pressure on a 1" tire is 140 psi and it's 100 psi on a 1 1/4" tire but you're
    only planning on running 100 psi why can't you run the 1 1/4" at 100 psi?

    > The narrower tire will have a higher optimal pressure and thus a lower rolling resistance.
    > The wider tire will weigh more and roll slower, but give you a plusher ride, especially on
    > rough roads.
    >

    And the wider tire has less rolling resistance at the same pressure just like I said (due to less
    hysteresis). The wider tire will roll faster than the skinnier tire at the same pressure. Did you
    read what I said? "At a given pressure fatter tires have less rolling resistance".

    Greg

    --
    "Destroy your safe and happy lives before it is too late, the battles we fought were long and hard,
    just not to be consumed by rock n' roll..." - The Mekons
     
  10. G.T. wrote:
    > Ken wrote:
    >
    >> "G.T." <[email protected]> wrote in news:[email protected]:
    >>
    >>> I'd go with the 1 1/4. The only benefit of narrow tires is the ability to run 110 psi and up. At
    >>> a given pressure fatter tires have less rolling resistance (due to less hysteresis).
    >>
    >>
    >>
    >> While that partially is true, it is not a valid argument. If two tires have identical
    >> construction, except that one is wider, you should *not* run them at the same pressure.
    >
    >
    > Why not? If the max pressure on a 1" tire is 140 psi and it's 100 psi on a 1 1/4" tire but you're
    > only planning on running 100 psi why can't you run the 1 1/4" at 100 psi?
    >
    >> The narrower tire will have a higher optimal pressure and thus a lower rolling resistance.
    >> The wider tire will weigh more and roll slower, but give you a plusher ride, especially on
    >> rough roads.
    >>
    >
    > And the wider tire has less rolling resistance at the same pressure just like I said (due to less
    > hysteresis). The wider tire will roll faster than the skinnier tire at the same pressure. Did you
    > read what I said? "At a given pressure fatter tires have less rolling resistance".
    >
    > Greg
    >

    Not sure if I can get my head around that one. You're saying that if I had a 1 meter wide tire, and
    a 1cm wide tire (assuming smooth tread), then the 1 meter wide tire will roll faster, not taking int
    account weight and momentum? The tire is going to have a larger contact patch, which means more
    deformity of the tire with the surface its on, which means more energy loss (hence more hysteresis).
    Granted, it'll have massive grip, but not sure if I agree with your statement. I'm probably wrong,
    and would love to be proved so, but I can't get my mind around that one.

    Jon Bond
     
  11. G.T.

    G.T. Guest

    Jonathan Bond wrote:
    >
    >
    > G.T. wrote:
    >
    >> Ken wrote:
    >>
    >>> "G.T." <[email protected]> wrote in news:[email protected]:
    >>>
    >>>> I'd go with the 1 1/4. The only benefit of narrow tires is the ability to run 110 psi and up.
    >>>> At a given pressure fatter tires have less rolling resistance (due to less hysteresis).
    >>>
    >>>
    >>>
    >>>
    >>> While that partially is true, it is not a valid argument. If two tires have identical
    >>> construction, except that one is wider, you should *not* run them at the same pressure.
    >>
    >>
    >>
    >> Why not? If the max pressure on a 1" tire is 140 psi and it's 100 psi on a 1 1/4" tire but you're
    >> only planning on running 100 psi why can't you run the 1 1/4" at 100 psi?
    >>
    >>> The narrower tire will have a higher optimal pressure and thus a lower rolling resistance. The
    >>> wider tire will weigh more and roll slower, but give you a plusher ride, especially on rough
    >>> roads.
    >>>
    >>
    >> And the wider tire has less rolling resistance at the same pressure just like I said (due to less
    >> hysteresis). The wider tire will roll faster than the skinnier tire at the same pressure. Did you
    >> read what I said? "At a given pressure fatter tires have less rolling resistance".
    >>
    >> Greg
    >>
    >
    > Not sure if I can get my head around that one. You're saying that if I had a 1 meter wide tire,
    > and a 1cm wide tire (assuming smooth tread), then the 1 meter wide tire will roll faster, not
    > taking int account weight and momentum? The tire is going to have a larger contact patch, which
    > means more deformity of the tire with the surface its on, which means more energy loss (hence more
    > hysteresis). Granted, it'll have massive grip, but not sure if I agree with your statement. I'm
    > probably wrong, and would love to be proved so, but I can't get my mind around that one.
    >

    I interchanged "less rolling resistance" and "rolling faster" because I was talking about tires of
    only 1/4" difference in width and assuming they would be constructed similarly. A 1 1/4" wide tire
    at 100 psi (if it's rated for 100 psi) will roll faster than a 1" wide tire at 100 psi if they are
    constructed similarly. This is tires 101.

    http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html

    The reasons narrower tires usually have less rolling resistance is that they are usually constructed
    differently than wider tires. If you take a Conti Grand Prix 25mm and a 20mm and inflate them to 95
    psi the 25mm is going to be faster. This isn't specifically mentioned in the r.b.t. FAQ but this has
    been discussed at length on r.b.t. I was schooled on this long ago.

    Greg
    --
    "Destroy your safe and happy lives before it is too late, the battles we fought were long and hard,
    just not to be consumed by rock n' roll..." - The Mekons
     
  12. Ken

    Ken Guest

    "G.T." <[email protected]> wrote in news:[email protected]:
    > And the wider tire has less rolling resistance at the same pressure just like I said (due to less
    > hysteresis). The wider tire will roll faster than the skinnier tire at the same pressure. Did you
    > read what I said? "At a given pressure fatter tires have less rolling resistance".

    Sheldon Brown says "at the same pressure" is a bogus argument. See:
    http://www.sheldonbrown.com/tires.html#width
     
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