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  1. #1
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    Why 10 spd Instead of 9 spd?

    Other than getting one less gear, of course, it seems to me that one could change the chain rings up front and get the same gear combinations while running the cheaper 9 speed stuff. What am I missing?

    Fred

  2. #2
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    For the true 2x10 system, I suspect the two remaining chainrings are closer to the center of the chainline. The smaller ring being moved outboard and the outer ring being move inboard. This allows the use of all the cassette cogs without creating a cross-chain condition. Additionally, with the chain more parallel to the chainline, there will be less chain rub issues with the front derailleur.

    It's interesting how SRAM and Shimino are approaching the 10 sp option. SRAM with their XX is asking us to pedal bigger gear ratios, Shimano using the standard triple crankset (24-32-44) and 11-36 cassette is allowing us to pedal essentially the same gear rations with less gap between them . I think Shimano is trying not to be left behind by the 10 sp conversion but is unwilling to commit to the real advantages of a 2x10 drivetrain. Personally, I think the Shimano 10 sp. upgrade will made by a confused consumer that is willing to spend $600-$800 to get a 36 gear that they probably don't need, or possibly gaining some advantage by slightly reducing the gaps between gear ratios. The next two drivetrain years are going to be interesting. I'll make the conversion, I just want to make the right one. I believe the two chainring concept will eventually become the standard.
    Last edited by MarkHL; 11-16-2010 at 07:23 PM.

  3. #3
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    Not sure how everyone else is justifying it, but I would like to move to 10spd in the future because, if using an 11-36t cassette, the wider range of cog sizes in the rear means you can spend more time on one chainring and spend less time using the slower front shifting. It also gives a single chainring setup more range. If you are comparing to an 11-32t or 11-34t cassette , then yes you can get the same setup in 9spd. The 11-36t cassettes are specifically why I want 10spd

    As for SRAM asking you to push bigger gears than Shimano... i think the opposite is actually more true. For the parts that most people can actually afford (X.9, X.7) SRAM offers triple cranks with a 22t granny, whereas all of the Shimano's 10spd cranks have a 24t granny. With a 24t granny and a 36t cog Shimano's gearing is actually higher than the old 22x34 combo, it's close to but not quite as high as a 22x32 combo. So upgrading doesn't give you any lower gearing, but it gives you an extra cog's worth of range from the middle ring especially

  4. #4
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    We pretty much hit the sweet spot at 7 out back. Anything after that has been fluff.
    "It looks flexy"

  5. #5
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    Quote Originally Posted by gticlay
    We pretty much hit the sweet spot at 7 out back. Anything after that has been fluff.
    I personally disagree, only because I like cassettes with a minimum range of 11-32t and that kind of setup with 7 speeds leads to some huge jumps between gears. For some types of riding that is fine and even preferable, for other its no fun at all

  6. #6
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    Boomn

    I edited my first post when I remembered the Shimano triple uses a 24 small ring. I then read your post where you stated correctly the gear ratios are the same.
    My statement about SRAM asking you to push bigger gears was based on a 26x36 gear ratio (.72) which is higher than a 22x34 (.64).
    Best of my knowledge SRAM XX is offering these chain ring combinations: (26-39), (28-42), (30-45). I can't find number of teeth per cog on their XX 11-36 cassette, but it should be similar to Shimano's.

    I agree that staying on one ring has an advantage, since 90% of my small to middle ring shifts involve a double shift, because I also adjust what cog I'm on too.
    Last edited by MarkHL; 11-15-2010 at 09:49 AM.

  7. #7
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    Quote Originally Posted by RagerXS
    Other than getting one less gear, of course, it seems to me that one could change the chain rings up front and get the same gear combinations while running the cheaper 9 speed stuff. What am I missing?

    Fred
    technically you could do the same thing with an even cheaper 7 or 8 speed setup. and of course some would argue why you even need more then one gear in the first place
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  8. #8
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    Quote Originally Posted by MarkHL
    For the true 2x10 system, I suspect the two remaining chainrings are closer to the center of the chainline. The smaller ring being moved outboard and the outer ring being move inboard. This allows the use of all the cassette cogs without creating a cross-chain condition. Additionally, with the chain more parallel to the chainline, there will be less chain rub issues with the front derailleur.

    It's interesting how SRAM and Shimino are approaching the 10 sp option. SRAM with their XX is asking us to pedal bigger gear ratios, Shimano using the standard triple crankset (24-32-42) and 11-36 cassette is allowing us to pedal essentially the same gear rations with less gap between them . I think Shimano is trying not to be left behind by the 10 sp conversion but is unwilling to commit to the real advantages of a 2x10 drivetrain. Personally, I think the Shimano 10 sp. upgrade will made by a confused consumer that is willing to spend $600-$800 to get a 36 gear that they probably don't need, or possibly gaining some advantage by slightly reducing the gaps between gear ratios. The next two drivetrain years are going to be interesting. I'll make the conversion, I just want to make the right one.
    Shimano's MTB 10-sp has been in development for many years. It only seems like they are playing catch up because XX hit the market sooner.

    It could be argued Dyna-Sys is a more refined system. Whether you agree with the design/performance goals is another matter.
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  9. #9
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    Quote Originally Posted by RagerXS
    Other than getting one less gear, of course, it seems to me that one could change the chain rings up front and get the same gear combinations while running the cheaper 9 speed stuff. What am I missing?

    Fred
    IMHO its because companies, bike shops, and websites want to sell more stuff. if they don't change stuff more often than not, then we won't buy it, and they don't make as much money. also, guys in R&D need to justify their jobs, so they'll come up with new ideas all the time. there will be an 11 speed set up probably at some point, who knows.

    there are probably advantages to a 10 speed set up, but there are probably disadvantages as well. just like the 26 vs 29 debate, there is never going to be one that is just "better" than the other.

    personally i could give a rat's a$$ about 10 speed... but i'll be in the market for a new bike next year most likely, and i'll probably end up getting some thing with a 2 x 10 because that's what'll come on it.
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  10. #10
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    Quote Originally Posted by MarkHL
    My statement about SRAM asking you to push bigger gears was based on a 26x36 gear ratio (.72) which is higher than a 22x34 (.64).
    Best of my knowledge SRAM XX is offering these chain ring combinations: (26-39), (28-42), (30-45). I can't find number of teeth per cog on their XX 11-36 cassette, but it should be similar to Shimano's.
    Yep, all correct. But my point is that XX doesn't matter for 95% of riders and shouldn't be used to represent everything SRAM does. For all the normal riders the 26t and 28t grannies are only an option not a requirement. For the X.0, X.9 and X.7 lines they are offering triple cranks with 22t grannies

  11. #11
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    Quote Originally Posted by boomn
    Yep, all correct. But my point is that XX doesn't matter for 95% of riders and shouldn't be used to represent everything SRAM does. For all the normal riders the 26t and 28t grannies are only an option not a requirement. For the X.0, X.9 and X.7 lines they are offering triple cranks with 22t grannies
    XX was the flagship for the 2x10 system. It doesn't seem like anyone else is really ready yet to commit to the two chainring crankset. (2 ringers with a bash guard don't count).
    So with the other 10 sp/triple options you are gaining only a partial advantage (and the new triples with 36 cogs are going to add overall weight to your bike).

    Clarkenstein: Obsolescence has always been a marketing strategy, but true technological improvements will out sell the hype.
    Last edited by MarkHL; 11-15-2010 at 12:23 PM.

  12. #12
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    Quote Originally Posted by MarkHL
    XX was the flagship for the 2x10 system. It doesn't seem like anyone else is really ready yet to commit to the two chainring crankset. (2 ringers with a bash guard don't count).
    So with the other 10 sp. options you are gaining only a partial advantage (and the new triples with 36 cogs are going to add overall weight to your bike).
    Understood,it just wasn't clear to me what points of comparison you were trying to draw and which ones you weren't.

  13. #13
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    Quote Originally Posted by boomn
    I personally disagree, only because I like cassettes with a minimum range of 11-32t and that kind of setup with 7 speeds leads to some huge jumps between gears. For some types of riding that is fine and even preferable, for other its no fun at all
    You are thinking old school gearing. They could make 7 speed with a big range, just bigger gaps, which I would prefer. It's annoying having to make multiple clicks quite a bit of the time. I know I'm not the only one doing that since they have multi click's on the triggers now.
    "It looks flexy"

  14. #14
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    Quote Originally Posted by gticlay
    They could make 7 speed with a big range, just bigger gaps
    that's exactly what I said in my comment. I even said i could prefer it in certain circumstances

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    I'm learning a lot with this thread, and it's inspired me to do some research I hadn't considered until seeing some of the responses so thank you to all. This all came about because some guys I ride with have the new XT dyna-sys 3x10 setup and like the gearing. Meanwhile I nabbed a frame I'd like to build and can either go with new drivetrain or recycle the almost new Race Face Deus XC crank and the new 9 spd chains I have on hand. Then I'd put the old stuff back on the current bike and either keep it or sell it whole. Single speeds are not for me. I can see why some would dig them, but it's all up and down where I ride so my derailleurs get used often.

    I'm still undecided, but I am leaning toward sticking with 9 speed for now and this would be my plan:

    Change the small ring on my Race Face Deus to 24T
    Use Shimano SLX HG61 (for 29er) 12-36 cassette
    Move my XT/XTR shifters/derailleurs over from my current bike

    The new XT 11-36 has these gears: 36-32-28-24-21-19-17-15-13-11
    The old SLX 12-36 has these gears: 36-32-28-24-21-18-16-14-12

    I hardly ever use the 11T cog, so it won't be missed. I spend most of my time in the middle and on larger cogs, and you can see above that the five largest are identical. That SLX 12-36 is also 16g lighter than the XT 10sp 11-36 - not by a lot, but worth mention.

    As for the dedicated 2-ring cranks being more centered than the first two rings of a 3x crank, couldn't one simply use the same spacers that get installed to adjust the chainline in order to center the two smaller rings (the idea being to use a bash ring, not to screw up the large ring)?

    I'm not so attached to my stuff that I wouldn't sell and/or return it, and I'm not too proud of it to resist an upgrade. But for the gears I typically use most often this plan sure seems like an equivalent result for a lot less money.

    Fred

  16. #16
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    Quote Originally Posted by RagerXS
    That SLX 12-36 is also 16g lighter than the XT 10sp 11-36 - not by a lot, but worth mention
    9spd 12-36t = 425g
    10spd XT 11-36t = 350g

    it's about 20% heavier

  17. #17
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    Quote Originally Posted by RagerXS

    As for the dedicated 2-ring cranks being more centered than the first two rings of a 3x crank, couldn't one simply use the same spacers that get installed to adjust the chainline in order to center the two smaller rings (the idea being to use a bash ring, not to screw up the large ring)?

    Fred
    If you have a triple with a 50mm chainline (most external bearings BBs and many recent ISIS and Octalink) the chainline is more correct simply by removing the outer ring.
    SLX Crank 2ring vs 3ring - Chainline
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  18. #18
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    As boomn said, SRAM has triple cranks with a 22T granny. The 22-33-bash rings with an 11-36 cogset looks ideal for a non-racer 29er that sees trail-only duty. This is essentially what comes on the Specialized Stumpjumper FSR 29er Expert. For riding on the street or fast fire roads you might want the big chainring instead of the bashguard.

  19. #19
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    Quote Originally Posted by shiggy
    If you have a triple with a 50mm chainline (most external bearings BBs and many recent ISIS and Octalink) the chainline is more correct simply by removing the outer ring.
    SLX Crank 2ring vs 3ring - Chainline
    Hey Shiggy - I'm running a triple crank as a double with a bash. So the 32 middle ring is best lined up which gear now, the 5th from easiest on 9spd and 6th from easiest on 10 speed? Or 6th and 7th?
    "It looks flexy"

  20. #20
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    Removing the big ring...

    I believe some people would be surprised to learn that for a standard 11-34 9sp and a 22-32-42 crankset only the 13 and 11 cogs offer a larger (harder pedaling) ratio on the big ring. (See chart below)

    I removed my big ring in favor of a bash guard for the following reasons:

    1) more clearance for going over obstacles
    2) only the smallest cogs (11-13) offered more pedaling resistance
    3) the big ring is a safety hazard; basically a dirty saw waiting to cut into your lower leg when you crash.

    The second chart is the Shimano 10 speed ratios with a 24 small chain ring and 11-36 cassette.
    Attached Thumbnails Attached Thumbnails Why 10 spd Instead of 9 spd?-capture1.jpg  

    Why 10 spd Instead of 9 spd?-capturex.jpg  

    Last edited by MarkHL; 11-15-2010 at 12:28 PM.

  21. #21
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    I used to think ten gears would be overkill, and nine was more than plenty until my current 9-speed rig went down and I had to pedal my old backup bike, which is an 8-speed. I never thought I'd miss the difference between 8 and 9 gears, but I did. The gears were too far apart to find a comfortable cadence in some conditions, and I was forced to use the granny ring more often due to the smaller max cog.
    I can barely get my mouth around it.

  22. #22
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    Quote Originally Posted by boomn
    9spd 12-36t = 425g
    10spd XT 11-36t = 350g

    it's about 20% heavier
    Interesting. I guess it depends on the source of info until you actually put them both on the same scale. I was going by 320g for the 12-36 on Amazon. I see on Competitive Cyclist that it has a claimed weight of 305, but at the end of their writeup it says 423g. That's a 25% difference right there!

    Fred

  23. #23
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    Quote Originally Posted by RagerXS
    Interesting. I guess it depends on the source of info until you actually put them both on the same scale. I was going by 320g for the 12-36 on Amazon. I see on Competitive Cyclist that it has a claimed weight of 305, but at the end of their writeup it says 423g. That's a 25% difference right there!

    Fred
    Here's BTI's page for the HG61 cassettes. Looks like the other places are getting the weights mixed up between the different sizes of that model. A real world weight from the Weight Weenies listing is 419g

  24. #24
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    Quote Originally Posted by gticlay
    Hey Shiggy - I'm running a triple crank as a double with a bash. So the 32 middle ring is best lined up which gear now, the 5th from easiest on 9spd and 6th from easiest on 10 speed? Or 6th and 7th?
    Proper chainline is having the centerline of the chainrings (between the rings on a double) inline with the center of the cassette.

    On a 9-sp cassette this is the 5th cog (which is the only position where using a number for a cog position makes sense as there is no standard on whether you start counting with the smallest or largest cog).
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  25. #25
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    Quote Originally Posted by MarkHL
    XX was the flagship for the 2x10 system. It doesn't seem like anyone else is really ready yet to commit to the two chainring crankset. (2 ringers with a bash guard don't count).
    So with the other 10 sp/triple options you are gaining only a partial advantage (and the new triples with 36 cogs are going to add overall weight to your bike).

    Clarkenstein: Obsolescence has always been a marketing strategy, but true technological improvements will out sell the hype.
    Yeah... Shimano sure doesn't seem like they want to commit...

    I mean... they only offer four different two ring options with XTR...

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