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  1. #1
    PacktInACrushdTinBox LuckyKarma's Avatar
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    What size tire do I need?

    Hey, I just picked up an old Concord road bike at a yard sale today, but it didn't have any tires on it so I'm on a mission to find the right size. The diameter of the rim is about 25.5". I compared it against the stock rims/tires on my Trek, and the diameter of the rims on my Trek are 25" and the tires are 700x25c. I'm not really sure how to interpret this as I don't know much about bike tires at all, does anyone have any idea of what size tires I need?
    '07 Trek 1000
    70's Concord Freedom 12

  2. #2
    Klaatu barada nikto cascade168's Avatar
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    Read this article and it should answer your questions:

    http://www.sheldonbrown.com/tire_sizing.html
    "Work is the curse of the drinking class."
    - Oscar Wilde

  3. #3
    PacktInACrushdTinBox LuckyKarma's Avatar
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    Quote Originally Posted by cascade168 View Post
    Read this article and it should answer your questions:

    http://www.sheldonbrown.com/tire_sizing.html
    I've read through that a few times but it still doesn't make much sense to me. It says older road bikes are normally 27xsomething, but my Trek with the smaller rim uses a 700x25 tire? Sorry I'm not catching onto this, it's just not making much sense...

    With only a half inch difference between my Trek and my Concord's rims, will a 700mm tire fit my Concord too?
    Last edited by LuckyKarma; 07-27-07 at 09:50 PM.
    '07 Trek 1000
    70's Concord Freedom 12

  4. #4
    PacktInACrushdTinBox LuckyKarma's Avatar
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    I'm wanting to get in on the 20% off sale ending tonight at Nashbar, if anyone could answer this question ASAP I would GREATLY appreciate it

    When sheldonbrown.com says older road bikes use 27" tires, would a bike from the 70s or early 80s be classified as an old bike?
    '07 Trek 1000
    70's Concord Freedom 12

  5. #5
    Pwnerer Wordbiker's Avatar
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    When you say "greatly", does this mean a cash reward?
    Quote Originally Posted by ahsposo View Post
    Ski, bike and wish I was gay.

  6. #6
    PacktInACrushdTinBox LuckyKarma's Avatar
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    Quote Originally Posted by Wordbiker View Post
    When you say "greatly", does this mean a cash reward?
    No, but you can have the satisfaction of knowing you helped save a college kid from a looong walk to campus every day
    '07 Trek 1000
    70's Concord Freedom 12

  7. #7
    rebmem
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    Have you tried to put on the 700 X 25 from your trek bike onto the bike?

  8. #8
    PacktInACrushdTinBox LuckyKarma's Avatar
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    Quote Originally Posted by griggsaks View Post
    Have you tried to put on the 700 X 25 from your trek bike onto the bike?
    No, I don't have any experience swapping out tires and I'd rather not do that unless I absolutely have to. My Trek is my ride to work, so I can't really afford to experiment with it. Would it work even though the Concord rim is slightly larger?
    '07 Trek 1000
    70's Concord Freedom 12

  9. #9
    Senior Member
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    27" rims are about 1/3" larger diameter than 700C rims and the tires for one will not fit on the other.

  10. #10
    PacktInACrushdTinBox LuckyKarma's Avatar
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    Quote Originally Posted by AndrewP View Post
    27" rims are about 1/3" larger diameter than 700C rims and the tires for one will not fit on the other.
    So I made the right choice by ordering a pair of 27x1-1/4" tires? Hopefully so, the 20% meant free shipping + $1 off
    '07 Trek 1000
    70's Concord Freedom 12

  11. #11
    Pwnerer Wordbiker's Avatar
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    Quote Originally Posted by LuckyKarma View Post
    No, but you can have the satisfaction of knowing you helped save a college kid from a looong walk to campus every day
    I think walking is good exercise. Cash however does a good deal of talking.
    Quote Originally Posted by ahsposo View Post
    Ski, bike and wish I was gay.

  12. #12
    Senior Member Bill Kapaun's Avatar
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    700c rims have a bead seat dia. of 622 MM or 24.49"
    27" rims have a bead seat dia. of 630 MM or 24.80".

  13. #13
    SE Wis dedhed's Avatar
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    Try looking carefully everywhere on the rim. They are often stamped with the rim size somewhere.

  14. #14
    PacktInACrushdTinBox LuckyKarma's Avatar
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    Quote Originally Posted by dedhed View Post
    Try looking carefully everywhere on the rim. They are often stamped with the rim size somewhere.
    There is "12 05 19" stamped several times on the rim, but I don't see anywhere that tells the rim size. Unless these numbers do, I don't really understand what they mean.
    '07 Trek 1000
    70's Concord Freedom 12

  15. #15
    cab horn
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    27" x whatever is NOT compatible with 700c x whatever\

    If the rims on your concorde are larger than your Trek, and the concorde is an older road bike, it most likely is 27" x whatever. The easisest way to confirm is just to read the size of the tire. Alternatively, if the rims are steel, that's usually a good indication of 27" wheels.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  16. #16
    Retrogrouch
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    Quote Originally Posted by LuckyKarma View Post
    So I made the right choice by ordering a pair of 27x1-1/4" tires? Hopefully so, the 20% meant free shipping + $1 off
    I just measured the rims on my 32 year old Fuji and they are 25.5" in diameter. They use 27" tires so the 27X1 1/4" tires you bought should work.

  17. #17
    rebmeM roineS JanMM's Avatar
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    Late '70's Schwinn Letours, etc., were 27"

  18. #18
    PacktInACrushdTinBox LuckyKarma's Avatar
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    Quote Originally Posted by J.P. View Post
    I just measured the rims on my 32 year old Fuji and they are 25.5" in diameter. They use 27" tires so the 27X1 1/4" tires you bought should work.
    Awesome! Thanks for measuring your rims, that put my mind at ease
    '07 Trek 1000
    70's Concord Freedom 12

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