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  1. #1
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    SRAM X.7 vs X.9 and Shimano XT vs. LX

    I'm looking at getting back into mountain biking after a 3 year hiatus. Can someone please tell me the main difference between :

    1. SRAM X.9 and X.7. Is it worth paying more money for the X.9?

    2. Shimano XT and LX. Is the XT that much better than LX?

    Basically, is the weight that big of a difference betwwen the two? Does the higher end component (XT and SRAM X.9) function that much better? Would you pay $300-400 dollars more for a bike that had XT or SRAM X.9 components as opposed to LX and SRAM X.7?

    Thanks

  2. #2
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    Couldn't say for the SRAM gear, but for Shimano the XT is the point in the range where the major design differences are implimented. The XT derailleurs are lighter, but they also use higher-rate springs so they're more responsive than other derailleur behind them in the range. XT shifters also have stronger springs and use ball-bearing supported shift mechanisms, rather than plastic bushes. The advantage of this is more a matter of longevity than anything else. Most Shimano shifters work with a similar performance, but will wear out more quickly. The bearing supported mechanism also gives the XT a much more solid feel, while at he same time being slightly easier, lighter, to operate.
    I've found all Shimano cassettes to be hard wearing, but the XT seems to go on forever. I'm currently using Ultegra, the road version of the XT, but the standard XT has been my cassette of choice for a few years.

    I don't have much experience of Shimano brake, cable or hydraulic, so couldn't comment on any diffrerences that may exist there.

    In my opinion, the extra cost for the XT range over the LX is well worth it.
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  3. #3
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    Yes and Yes

    Steve did a very nice job of explaining LX and XT, so I'll take a shot at the X.7 and X.9 differences for model year 2007. This doesn't necessarily apply to 2006 and older models. You will find similar differences in weight and preformance between the X.9 over the X.7 components. I can't specifically state what the major differences in material composition and spring rates are between the two, but the X.9 will offer quickler and more precise shifting, and be lighter in weight. Another major difference you will find is when you compare the shifters. The X.9 has more adjustibility in terms of positioning of the bar clamp and paddles, and has a zero travel loss feature which austensibly means that there is no delay in shifting. Engagement of the derailleur begins as soon as you move the paddle.

    Is it worth the extra cost? Yes. Keep in mind that the additional $300-$400 you quote on a bike equipped with higher end Shimano or SRAM components will likely have a better fork and/or other upgrades that make up the difference in cost. If you can afford the additional layout of cash, I highly recommend you do so.

    Bob
    'If Wal-Mart sold parachutes, who would jump?' Frank Havnoonian (quoting his father) Drexel Hill Cyclery

  4. #4
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    Quote Originally Posted by Call_me_Clyde
    The X.9 has more adjustibility in terms of positioning of the bar clamp and paddles, and has a zero travel loss feature which austensibly means that there is no delay in shifting. Engagement of the derailleur begins as soon as you move the paddle.
    which paddle are we talking about here? obviously, the derailer moves when you shift to a lower gear (large thumb paddle). but for shifting into a higher gear, you still have to release the paddle befor it will shift, just like shimano (excepting maybe the new xtr).

    i guess this is a topic for another thread.

  5. #5
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    My bad. Confusing verbiage.

    Quote Originally Posted by Cyco-Dude
    which paddle are we talking about here? obviously, the derailer moves when you shift to a lower gear (large thumb paddle). but for shifting into a higher gear, you still have to release the paddle befor it will shift, just like shimano (excepting maybe the new xtr).

    i guess this is a topic for another thread.
    Let me see if I can clarify:

    1) The X.9 shifters have some adjustibility with regard to the clamp positioning, as well as the paddle positioning relative to the clamp.

    2) In addition to this ability to have some adjustibility of the positioning, the X.9 shifters deploy the zero travel loss. Here's how SRAm describes it:

    Standard shifters need 7 to 15 degrees of “lost travel” to engage the shifting pawl before beginning shifts. With SRAM’s Zero Loss shifters, the pawl is always engaged, which means as soon as you push the trigger, the cable moves resulting in the fastest, smoothest shifts you've ever experienced

    I hope that clarifies what I was trying to explain.

    Bob
    'If Wal-Mart sold parachutes, who would jump?' Frank Havnoonian (quoting his father) Drexel Hill Cyclery

  6. #6
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    I asked a similar question recently, I’m not an expert but this is what I found in addition to the information above.
    Shimano has a hinged "B Knuckle" - Sram is a fixed "B Knuckle". Basically, Less effort, less gear hopping, with fewer adjustments.

    Checkout this video, pretty cool....
    http://www.youtube.com/watch?v=AZQf1bduGYs

  7. #7
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    Quote Originally Posted by bikefun
    Checkout this video, pretty cool....
    http://www.youtube.com/watch?v=AZQf1bduGYs
    I keep seeing that video referenced here and there, but I'm always surprised by the conclusions some people draw from it. It shows that the Shimano rear derailleur is designed to move at two pivot points as the chain tension changes, whereas the SRAM is designed to move primarily at one pivot point. I don't see how this relates to shifting performance. All it's telling us is that the two systems work differently, not that one system is "better" than the other.

    The test adds blue and red lines to demonstrate that the upper arm of the derailleur moves more on the Shimano than it does on the SRAM. People seem to want to conclude that less movement in this particular area equates to better performance, but there is nothing in this test to indicate that this is necessarily the case. Note that I'm NOT saying that this "isn't" the case -- I'm simply saying that this particular video doesn't show this.

    I'll admit that the video is interesting, but what's ALSO interesting to me is how readily some people want to draw conclusions from it that don't necessarily follow.

    Larry

  8. #8
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    Quote Originally Posted by lalittle
    I keep seeing that video referenced here and there, but I'm always surprised by the conclusions some people draw from it. It shows that the Shimano rear derailleur is designed to move at two pivot points as the chain tension changes, whereas the SRAM is designed to move primarily at one pivot point. I don't see how this relates to shifting performance. All it's telling us is that the two systems work differently, not that one system is "better" than the other.

    The test adds blue and red lines to demonstrate that the upper arm of the derailleur moves more on the Shimano than it does on the SRAM. People seem to want to conclude that less movement in this particular area equates to better performance, but there is nothing in this test to indicate that this is necessarily the case. Note that I'm NOT saying that this "isn't" the case -- I'm simply saying that this particular video doesn't show this.

    I'll admit that the video is interesting, but what's ALSO interesting to me is how readily some people want to draw conclusions from it that don't necessarily follow.

    Larry
    What I think it's trying to show is if you were pedaling and shifting while going down rough terrain like in the video, a derailer with less movement would provide you with more precise and faster shifts.
    [SIZE="3"]The secret to mountain biking is pretty simple. The slower you go the more likely it is you'll crash. ~Julie Furtado[/SIZE]

  9. #9
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    Quote Originally Posted by [CrazyRick_11]
    What I think it's trying to show is if you were pedaling and shifting while going down rough terrain like in the video, a derailer with less movement would provide you with more precise and faster shifts.
    My point is that it doesn't show this -- i.e. you simply can't draw that conclusion from what the video shows. There is some degree of "suggestive logic" to make that assumption -- i.e. it kind of "seems" like that may be the case -- but factually there is nothing in that video that tests shifting performance. The video simply doesn't show that more movement in the upper arm of the derailleur effects shifting performance.

    Consider, for example, that more movement allowed in the upper arm of the derailleur may result in more consistent tension on the section chain that engages the cassette. If this was the case, it could in turn benefit shifting performance. I'm NOT saying that this is the case -- I have no idea if it is or not. I'm simply saying that given the TOTAL lack of any shifting performance testing, this theory is just as plausible as the idea that more movement equates to performance problems.

    People need to limit their conclusions to what the video actually shows, and all it ACTUALLY shows is a difference in the way the derailleur systems work. It does nothing to show whether one works better than the other.

    Larry

  10. #10
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    Quote Originally Posted by lalittle
    My point is that it doesn't show this -- i.e. you simply can't draw that conclusion from what the video shows. There is some degree of "suggestive logic" to make that assumption -- i.e. it kind of "seems" like that may be the case -- but factually there is nothing in that video that tests shifting performance. The video simply doesn't show that more movement in the upper arm of the derailleur effects shifting performance.

    Consider, for example, that more movement allowed in the upper arm of the derailleur may result in more consistent tension on the section chain that engages the cassette. If this was the case, it could in turn benefit shifting performance. I'm NOT saying that this is the case -- I have no idea if it is or not. I'm simply saying that given the TOTAL lack of any shifting performance testing, this theory is just as plausible as the idea that more movement equates to performance problems.

    People need to limit their conclusions to what the video actually shows, and all it ACTUALLY shows is a difference in the way the derailleur systems work. It does nothing to show whether one works better than the other.

    Larry
    Point understood. I own a Sram X.7 rear dr. and from my own personal experience, the Sram is much better at shifting under rough/aggressive conditions, like in the video. I have tried Shimano and it does not preform as well under the same conditions. In this case for me the video is not an assumption. It's fact.
    CR11
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  11. #11
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    Quote Originally Posted by [CrazyRick_11]
    Point understood. I own a Sram X.7 rear dr. and from my own personal experience, the Sram is much better at shifting under rough/aggressive conditions, like in the video. I have tried Shimano and it does not preform as well under the same conditions.
    Trying them yourself is really the ONLY way to really know if one performs better than the other.

    In this case for me the video is not an assumption. It's fact.
    CR11
    Now we're right back where we started. The video has no bearing on whether or not the SRAM shifts better in rough conditions -- it doesn't show shifting, and the upper derailleur arm movement doesn't indicate anything in this regard. The upper arm moves more on the Shimano, but this is NOT evidence of worse shifting. There is NO shifting taking place in the video, so no conclusions can be drawn in this regard. You can't jump to the assumption that more upper arm movement equates to worse shifting.

    All the video shows is that the two systems work differently. Your experience is what matters. The fact that the SRAM works better for you might not have anything to do with the upper arm movement -- there are plenty of other design factors involved.

    Larry

  12. #12
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    "Now we're right back where we started.... "

    Larry, most people will see only what they want to see, or what they are told, assuming that matches up with what they want to be told. Especially, for some very odd reason, when it comes to SRAM vs Shimano. Banged your head on any walls recently?

  13. #13
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    The Sram vs. Shimano saga will never end...
    [SIZE="3"]The secret to mountain biking is pretty simple. The slower you go the more likely it is you'll crash. ~Julie Furtado[/SIZE]

  14. #14
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    The video

    Quote Originally Posted by lalittle
    All the video shows is that the two systems work differently. Your experience is what matters. The fact that the SRAM works better for you might not have anything to do with the upper arm movement -- there are plenty of other design factors involved.

    Larry
    I've seen the video, and you're right, it really doesn't show anything of significance. It really does boil down to your experience. My experience is that I still prefer the performance of my SRAM equipped bikes over my Shimano equipped bike.

    Like Crazy Rick said. The debate will never end.

    Bob
    'If Wal-Mart sold parachutes, who would jump?' Frank Havnoonian (quoting his father) Drexel Hill Cyclery

  15. #15
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    The video shows that your chain isn't jumping around and knocking against the chainstays. It also shows that the chain is far less likely to jump itself off the chainrings.

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