road gearing combinations

Discussion in 'Cycling Equipment' started by Ronanmk, May 5, 2005.

  1. Ronanmk

    Ronanmk New Member

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    Hi everyone. I recently purchased a Giant TCR1 with Ultegra 10 speed. It came with a 53-39 / 11-23 gearing combination, that Im not quite happy about now.
    From my kind of riding and some calculations that I've done, looks like my dream combo is something like a 53-42 / 13-25.

    My questions:

    - Does shimano make 42 chainrings for Ultegra 10 speed? (I've not seen this in their web site)
    - If they don't, is there any other 42 chaingring out there that can be used with 10 speed ultegra?
    - Any comments on the 13-25 gearing?.

    Thanks every one, I really appreciatte your comments
     
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  2. cydewaze

    cydewaze New Member

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    What about the stock gearing don't you like? Just curious.
     
  3. artmichalek

    artmichalek New Member

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    It sounds like you're trying to cut back the high end a bit without changing the lower gears? There's no Ultegra 42 inner chainring, but FSA makes one.
     
  4. boudreaux

    boudreaux New Member

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    All it takes is a generic 130BCD 42 for the inner ring.
     
  5. bikeguy2004

    bikeguy2004 New Member

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  6. txzen

    txzen New Member

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    So, you want to decrease your "top" gear, keep your lowest/climbing gear essentially the same, and just have smaller increments between them?
     
  7. gclark8

    gclark8 New Member

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    I am also in Perth and have reached a similar conclusion to that of Ronanmk, however this may be for different reasons.

    I curently have a triple 52/42/32, and 12-25 (9) cassette (105) and find myself constantly looking for the "missing" 16 and 18 tooth rear sprockets.

    My conclusion was to go for Ultegra10 with 13-25 or even 13-27 with a triple on the front. These can be purchased locally through any good Giant/Shimano dealer. Try Runners World in West Perth if your LBS can't help.
     
  8. Ronanmk

    Ronanmk New Member

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    Exactly. I never drop to the 11th cog, and very hardly ever to the 12th. For my kind of riding, 53-42 / 13-25 would give me:

    - Good top speed for my fitness level (~48kmph @90 rpm)
    - A nice range of 1 step increments (13-19)
    - Better speed at medium range with the 42 chainwheel (the 39 would give me ~29 max speed at the 16th cog @ 90 rpm - too low)
    - A good lower range in case I need it (Perth is not THAT hilly)

    I'll try runner's world. Thanks!
     
  9. House

    House Banned

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    But by increasing the chainring size to 42 and changing the sprocket from starting at 11 to 13, the difference is not that much and the higher sprocket actually workls out to be slightly bigger. It seems to me that you would be spending money for very little difference. I had a 53/42 before and know what it is like. I think you would be wasting your money for something so slight.
     
  10. Ronanmk

    Ronanmk New Member

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    Mmmm...I dont quite follow. I'm not going to use the 42 chainring with the lower (13-15) gears.
    This is what the gearing looks like:
    53/42/13-25 '@90 RPM
    53.0 Kmph 42.0 Kmph
    13 4.1 48.4
    14 3.8 45.0
    15 3.5 42.0
    16 3.3 39.4 2.6 31.2
    17 3.1 37.0 2.5 29.4
    18 2.9 35.0 2.3 27.7
    19 2.8 33.1 2.2 26.3
    21 2.0 23.8
    23 1.8 21.7
    25 1.7 20.0

    But, since I'm in a 53-39 / 11-23 combo now, its a two step process...first change the cassette, later on change the small ring.

    Cheers
     
  11. gclark8

    gclark8 New Member

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    Ron,

    I agree with changing the cassette first.
    Your lowest gear with 39/23=1.69, with 42/25=1.68.
    Try the 39/25=1.56 first, it may make your favourite hill just that bit easier. You are not loosing any top speed by leaving the small ring small, I see only advantages in having the one lower gear, Spring St for example.
     
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