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  1. #1
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    Chainring question

    Looking for a used crankset and a friend of mine is selling me a shmano xtr with 48-34-24 chainrings and my mtb originaly supposed to come with 44Ax32Ax22A, what could be the difference on gears?
    BTW, what the letter A stands for?

    The frame is a specialized s works enduro.

    Thanks

  2. #2
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    The rings on your buddies cranks aren't OE and are a little bigger across the board with the big ring being a pretty tall gear. The "A" behind your chainrings refer to Shimano's chainring spec. They make an A and a B version and it doesn't really matter which you use as long as they all match.

  3. #3
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    Thanks bro for clarifying that.

  4. #4
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    Quote Originally Posted by wellcraft View Post
    Looking for a used crankset and a friend of mine is selling me a shmano xtr with 48-34-24 chainrings and my mtb originaly supposed to come with 44Ax32Ax22A, what could be the difference on gears?
    BTW, what the letter A stands for?

    The frame is a specialized s works enduro.

    Thanks
    The 44x32x22 is a compact set of chainrings while the 48x34x24 is the old standard size bigger bolt center diameter (bcd). You will have a bit less clearance with the 48 tooth gear.

    From Sheldon Brown's website:
    "Compact Drive (MTB triple)
    A system of using smaller-than-normal sprockets front and rear. This has the advantage of saving a small amount of weight, improving chainwheel clearance for mountain bikes, and perhaps making a slight improvement in shifting. This is done by going to a smaller bolt circle, typically 94 mm/58 mm or 104 mm/64 mm B.C.D.

    The downside of compact drive is significantly reduced chain life, and decreased interchangeability of parts. I consider compact drive to be a very bad idea for mountain bike use, but it seems to have become ubiquitous.

    For mountain bike usage, compact drive typically uses 22/32/42 tooth chainwheels as opposed to the 48-38-28 or 46-36-24 used on earlier mountain bikes.

    The original mountain bike cranks were mostly 5-bolt 110 mm/74 mm BCD. "Compact Drive" cranksets usually use the 94 mm/58 mm BCD 5 bolt, or 104 mm/64 mm 4 bolt cranks, as opposed to full-size systems that have 24-28 tooth lows and 46 or 48 tooth highs on 110 mm/74 mm BCD cranks."

    Well, didn't know that he didn't like compact drives...

    urmb ]-
    “Nothing compares to the simple pleasure of riding a bike.” ~ John F. Kennedy

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