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  1. #1
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    Different Crank Arm q-factors

    I am currently set up with a Sram XX1 156q crank set, but I want to try the stages cycling crank arm power meter. It replaces the drive side crank arm with an aluminum arm that has a sensor on the side. Only problem is that the x9 crank arms that they offer are all 168q.

    Basically, this would shift the center by 6mm. Is this that noticeable? Problematic? Any advice would be appreciated.

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  2. #2
    Trail Ninja
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    Would that be as noticeable as having one of your cleats off-set by 6mm? Or as noticeable as wearing thinner socks and changing the insoles in your shoe?

  3. #3
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    That's exactly the perspective I needed. Sometimes I just get stuck in the details. Thanks for the wake up slap! :-)
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  4. #4
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    So I went to buy it and BB30 version isn't coming till Summer 2013 :-(

    I suppose it will roll around soon enough...

    Stages Power meter - X9 -- Stages Cycling Online Store
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  5. #5
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    Q-Factor is noticeable by some and not by others. I just went to the XX1 in the 156q to get the narrower q-factor and really like it and really noticed it over my older and much wider XT cranks.

  6. #6
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    Quote Originally Posted by azpoolguy View Post
    Q-Factor is noticeable by some and not by others. I just went to the XX1 in the 156q to get the narrower q-factor and really like it and really noticed it over my older and much wider XT cranks.
    That's called subjectivity. That's why I answered with a question, to give a perspective. I can give my personal thoughts, but would it help the OP much at all, besides tell him that people are different?

    I notice the Q factor difference, but I don't give the difference between my road bike and my mtn bike cranksets a second thought really. I recall looking down at my feet, using platform pedals, and often see my feet placed wide, even after 2 hours comfortably pedaling. My knees don't like being locked into clipless pedals. For natural comfort, I prefer the freedom of flats.

    If I were to order XX1, it wouldn't be in the narrower Q-factor, despite what researchers say about efficiency, and how spreading out your stance a little requires a somewhat proportionate amount of additional effort to move forward when walking/running. They speak of it in a road bike perspective, and pay the balance and stability loss of moving your stance closer together little heed. That balance and stability pays off in mtn biking though.

    Q factor pros/cons is another topic though. Just saying, 156 q factor crankarm plus 168 q factor crank arm being mismatched, is a small enough difference to balance out with other adjustments. Would BB spacers on the outboard side work too?

  7. #7
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    Quote Originally Posted by Varaxis View Post
    That's called subjectivity. That's why I answered with a question, to give a perspective. I can give my personal thoughts, but would it help the OP much at all, besides tell him that people are different?

    I notice the Q factor difference, but I don't give the difference between my road bike and my mtn bike cranksets a second thought really. I recall looking down at my feet, using platform pedals, and often see my feet placed wide, even after 2 hours comfortably pedaling. My knees don't like being locked into clipless pedals. For natural comfort, I prefer the freedom of flats.

    If I were to order XX1, it wouldn't be in the narrower Q-factor, despite what researchers say about efficiency, and how spreading out your stance a little requires a somewhat proportionate amount of additional effort to move forward when walking/running. They speak of it in a road bike perspective, and pay the balance and stability loss of moving your stance closer together little heed. That balance and stability pays off in mtn biking though.

    Q factor pros/cons is another topic though. Just saying, 156 q factor crankarm plus 168 q factor crank arm being mismatched, is a small enough difference to balance out with other adjustments. Would BB spacers on the outboard side work too?
    So does that mean my response was wrong or I gave the OP incorrect information? Or maybe I'm just confused by your lengthy response to my subjectivity.

  8. #8
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    Why do my longer posts confuse some people more than my shorter ones?

    Back to the main topic: OP, waiiiit a minute. Looks like you might have overlooked some other compatibility issues.

    I looked up the stages power meter. They offer a NDS crankarm in various alloy crankarm models with the meter attached. Does the XX1 crankset have a 3 piece, crankarm spindle type interface, or is the spindle mated permanently to the NDS? Asking because I often see the driveside crankarm in pictures and it doesn't have a spindle attached...

    And here I was gonna say there were spindle kits for pedals, like CB egg beaters, that are shorter too, that can help balance the Q factor difference.

    Edit: looked it up. I guess it's 3-piece. I see pictures showing the spindle attached to either. I guess what I should say, are you sure the spindle interface will match up? I recall some editor saying it looks sort of like a ISIS spline and a SRAM dev saying it's a slightly modified ISIS spline.

  9. #9
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    Quote Originally Posted by Varaxis View Post
    Why do my longer posts confuse some people more than my shorter ones?

    Back to the main topic: OP, waiiiit a minute.

    I looked up the stages power meter. They offer a NDS crankarm in various alloy crankarm models with the meter attached. Does the XX1 crankset have a 3 piece, crankarm spindle type interface, or is the spindle mated permanently to the NDS? Asking because I often see the driveside crankarm in pictures and it doesn't have a spindle attached...

    And here I was gonna say there were spindle kits for pedals, like CB egg beaters, that are shorter too, that can help balance the Q factor difference.

    Edit: looked it up. I guess it's 3-piece. I see pictures showing the spindle attached to either. I guess what I should say, are you sure the spindle interface will match up? I recall some editor saying it looks sort of like a ISIS spline and a SRAM dev saying it's a slightly modified ISIS spline.
    Generally, with SRAM cranks the spindle is attached to the driveside arm on GXP versions and the NDS arm with BB30 cranks.
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  10. #10
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    Quote Originally Posted by shiggy View Post
    Generally, with SRAM cranks the spindle is attached to the driveside arm on GXP versions and the NDS arm with BB30 cranks.
    Thanks. Didn't know that. Guess I jumped to the conclusion there, assuming it was 3 piece.

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