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  1. #1
    Senior Member Plow13's Avatar
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    same gear inches?

    is a 42-22 pretty much the same as a 35-18
    Cervelo S1 2010 (road) Lemond Alpe d'Huez 2004 (road)
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  2. #2
    Senior Member SweetLou's Avatar
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    I have no idea what size wheels you are running, so I can't give you the gear inches. But if you were running 26" then it would be 49.6 gear inches for the 42-22 and 50.6 for the 35-18

  3. #3
    Geek Extraordinaire sivat's Avatar
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    Assuming the same size tire, the 35/18 will feel slightly harder, but not much.
    I'd rather have a bottle in front of me than a frontal lobotomy.

    Sintesi Conversion Serotta Track

  4. #4
    Senior Member Bill Kapaun's Avatar
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    2% IS pretty much the same.

  5. #5
    Senior Member Plow13's Avatar
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    oops! i am running 700x32c...but yea its the same tire size...Just trying to get some info on some gear changes i am going to making in the future
    Cervelo S1 2010 (road) Lemond Alpe d'Huez 2004 (road)
    Trek 4500 2006 (mtb) Gary Fischer Utopia 2008 (commuter)
    Redline Conquest 2009 (cross) Redline 925 2009 (single speed)

  6. #6
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    Gear-inches = (chainring teeth/cog teeth)*wheel diameter. For both 27" and 700c wheels, the usual wheel diameter value used is 27.

    In your example a 42/22 would be (42/22)*27 = 51.5 gear-inches and a 35/18 would be (35/18)*27 = 52.5 gear-iches so the difference is about 2% which is negligable.

    You can use this equation for any gear combination you are interested in comparing.

  7. #7
    Videre non videri
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    For any two sprocket combos giving the same gear ratio, the one with the bigger sprockets will be heavier, but will also provide greater chain engagement, improving efficiency and safety slightly.

  8. #8
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    Essentially equivalent gearing. You will not be able to tell the 1" difference in gearing between the two.
    Il faut de l'audace, encore de l'audace, toujours de l'audace

    1980 3Rensho-- 1975 Raleigh Sprite 3spd
    1990s Raleigh M20 MTB--2007 Windsor Hour (track)
    1988 Ducati 750 F1

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