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  1. #1
    The Brutally Handsome
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    Which Of These Frames Has The Best XC Race Geo???

    Here are the geometry numbers for 5 different 18" 650b frames. Based on the information provided, which one do you think would be most ideal for XC racing?

    This may be too difficult to answer, but for the sake of conversation let's just say all of these framesets have the same exact builds.

    Also, I omitted the frame names so they won't influence your opinion.

    Black Frame:
    Head Angle 69
    Seat Angle 73
    Top Tube 600mm
    Head Tube Length 100mm
    Chain Stay 427mm
    Fork Offset ???
    Wheel Base 1100

    Green Frame:
    Head Angle 71
    Seat Angle 73
    Top Tube 581mm
    Head Tube Length 115mm
    Chain Stay 419mm
    Fork Offset 38mm
    Wheel Base 1054mm

    Orange Frame:
    Head Angle 71
    Seat Angle 73
    Top Tube 590mm
    Head Tube Length 115mm
    Chain Stay 427mm
    Fork Offset ???
    Wheel Base 1075mm

    Gray Frame:
    Head Angle 68
    Seat Angle 73
    Top Tube 597mm
    Head Tube 115mm
    Chain Stay 420mm
    Fork Offset 42mm
    Wheel Base 1104

    White Frame:
    Head Angle 70
    Seat Angle 73.5
    Top Tube 585mm
    Head Tube 115mm
    Chain Stay 432mm
    Fork Offset ???
    Wheel Base ???

  2. #2
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    green frame with grey fork.

  3. #3
    It's about showing up.
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    Empty data spots make this too hard for me.
    I don't rattle.

  4. #4
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    I don't think you could go wrong with any of them. With the info provided, the white frame looks the best on paper. The geometries change depending on what fork and travel you'll use.

  5. #5
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    Based on the numbers you have there i would likely go for the gray frame.

  6. #6
    the new Gilbert Grape
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    Green or orange for a XC race frame. The orange might be better for wide open courses and the green for more twisty.
    Each bicycle owned exponentially increases the probability that none is working correctly.

  7. #7
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    These are just my humble opinions, so take them for what they're worth to you.

    Just looking at numbers it's all in what you want a bike to do.

    Green, Orange and White are more typical of old skool XC. Green should be the quickest steering and will play better with old skool long stem/narrow bar setup. Orange stretches the top tube out quite a bit and adds a bit of length to the chainstays to make it a bit more stable, and most likely would want the next size shorter stem which you could balance with a wider bar. And White would be even more stable and better at the fast open stuff.

    I see Black and Grey and new skool XC geos. Black runs a pretty slack HTA but lowers the bars a fair bit putting more weight on the front and a more aggressive riding position. It also has a really long modern top tune making you want to run and even shorter stem and wider handlebars. Seatstays are short but not seriously so. This would be great if you're speed is fast or really want a better descender. Grey. Who puts a 68 HTA on an XC bike? That's trail geo. Stupid relaxed HTA, and again a very long top tube asking for short stem and wide bars, but HT length puts you up when compared to black. The shorter chainstay make up a bit for the slack HT though. This is a trail bike. It looks fun and relaxed, but really stable and very good for descending, jumping a bit, and riding all day. A DHer's "XC" bike.

    My ego wants me to tame the Green beast. For some reason I think the White would be a really good climber and stable. Orange is between the two, but really just a more stable green. But in the end I'd give black a go as I have an old skool XC rig already. I wouldn't own a gray, much less race one. But if you are coming from gravity and getting into XC, that might be the most comfortable for you.

  8. #8
    The Brutally Handsome
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    Give this man a cigar! Without any of the names you perfectly identified and placed each of the frames with their intended purpose!

    I appreciate the input and find your answers very interesting, but I realized after posting these figures that there are too many other variables involved. Just for example, three frames are steel (green, orange and white) one is carbon (black) and one is aluminum (gray). Then there's all the differences in forks . . . etc.

  9. #9
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    "Who puts a 68 HTA on an XC bike? That's trail geo. Stupid relaxed HTA, and again a very long top tube asking for short stem and wide bars, but HT length puts you up when compared to black. The shorter chainstay make up a bit for the slack HT though. This is a trail bike. It looks fun and relaxed, but really stable and very good for descending"

    my question: since im a terrible bike handler..why not a lightweight racer with stable/trail geo? (is there such a bike?) i hate my 71HA hardtail CD F5. i had an idea of using an adjstable headset on the Giant XTC 29er HT to go from steep 71.5 to at least 70.5

    wait! there may be such a bike! i dropped by Simi Valley Cycles and they have the Giant catalog to skim and low and behold! The new 27.5 XTC is at 69.5! thats a huge 2 degree difference between the 27.5 and 29 inch models

  10. #10
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    Quote Originally Posted by Sizzler View Post
    Give this man a cigar! Without any of the names you perfectly identified and placed each of the frames with their intended purpose!
    Seriously? Clearly I've learned something. My boss needs to give me a raise.

    Thank you for that. But you are right, I really didn't want to mention how much frame flex and stiffness can play into things too and potentially muddy the conversation and go way in over my head. Seems like there is about 1000 ways to tune a bike frame.

  11. #11
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    Quote Originally Posted by frank6262 View Post
    my question: since im a terrible bike handler..why not a lightweight racer with stable/trail geo? (is there such a bike?) i hate my 71HA hardtail CD F5. i had an idea of using an adjstable headset on the Giant XTC 29er HT to go from steep 71.5 to at least 70.5

    wait! there may be such a bike! i dropped by Simi Valley Cycles and they have the Giant catalog to skim and low and behold! The new 27.5 XTC is at 69.5! thats a huge 2 degree difference between the 27.5 and 29 inch models
    Well, there really is no reason not to, and yes the new XTC was built with a more stable geometry. But here's what I would argue; and again just opinion. Unless you are on a budget, why would you buy a hardtail trail bike? Go FS and be happier. If you don't have the handling skills to deal with a pointy XC racebike then why race one? Seems like you might need some more time riding and developing skills (and really having fun). Sounds like you might be at a point where the time saved by going to a lightweight hartail would be lost keeping it under control. I would also argue that a 71.5 HTA on a 29er isn't that steep. It's that pointed to help you flick those big wheels around. That said, I'd almost say a used 120mm trail bike with light bits on it (ie Trance 26") might be the faster option for you for now. If you have to have new I'd look at the Anthem 27.5 as well.

    BTW, I am not trying in anyway downplay your abilities or anything like that. I am all about the right tool for the right job and right person. Get a bike and set it up so it minimizes or even negates your weaknesses while not compromising your strengths. If a trail bike helps you go faster, then it helps you go faster. And say/own that you're faster on a trail bike. That's cool, very cool in fact. Just don't try to tell me its an XC race bike (something that it's not) is all I ask.

  12. #12
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    Quote Originally Posted by jazclrint View Post
    Well, there really is no reason not to, and yes the new XTC was built with a more stable geometry. But here's what I would argue; and again just opinion. Unless you are on a budget, why would you buy a hardtail trail bike? Go FS and be happier. If you don't have the handling skills to deal with a pointy XC racebike then why race one? Seems like you might need some more time riding and developing skills (and really having fun). Sounds like you might be at a point where the time saved by going to a lightweight hartail would be lost keeping it under control. I would also argue that a 71.5 HTA on a 29er isn't that steep. It's that pointed to help you flick those big wheels around. That said, I'd almost say a used 120mm trail bike with light bits on it (ie Trance 26") might be the faster option for you for now. If you have to have new I'd look at the Anthem 27.5 as well.

    BTW, I am not trying in anyway downplay your abilities or anything like that. I am all about the right tool for the right job and right person. Get a bike and set it up so it minimizes or even negates your weaknesses while not compromising your strengths. If a trail bike helps you go faster, then it helps you go faster. And say/own that you're faster on a trail bike. That's cool, very cool in fact. Just don't try to tell me its an XC race bike (something that it's not) is all I ask.

    ok i hereby promote you Jaz.. without a raise haha!

    "If you don't have the handling skills to deal with a pointy XC racebike then why race one?"

    would just slackening a pointy race bike (like the 29er 71.5degree XTC) with a Angleset give me a stable, slower steering, "race bike" ( i "race" Sport class, always last.. but i have fun!!)

    " I would also argue that a 71.5 HTA on a 29er isn't that steep."

    thats intersting .. ive never ridden a 29er.. so iwas wondering if i'd have more confidence bombing down a fireroad or loose slippery single track on a 29er.. even with 71.5 HA ??

    i also have an older 26" Trance and man i hate the squeeks, maintenance and flex of the rear suspension.. and hate the unsureness of the front end (71degree).. i rode a friends raked out Stumpjumper and man was it great! i could almost ride with one hand.. super stable front steering, front wheel never had a hint of washing out.. i think i need that... i need the rear end to slide out first.

    cant afford the new 27.5 Anthem
    thanks for sharing Jaz !

  13. #13
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    Quote Originally Posted by frank6262 View Post
    ok i hereby promote you Jaz.. without a raise haha!


    would just slackening a pointy race bike (like the 29er 71.5degree XTC) with a Angleset give me a stable, slower steering, "race bike" ( i "race" Sport class, always last.. but i have fun!!)

    " I would also argue that a 71.5 HTA on a 29er isn't that steep."

    thats intersting .. ive never ridden a 29er.. so iwas wondering if i'd have more confidence bombing down a fireroad or loose slippery single track on a 29er.. even with 71.5 HA ??

    i also have an older 26" Trance and man i hate the squeeks, maintenance and flex of the rear suspension.. and hate the unsureness of the front end (71degree).. i rode a friends raked out Stumpjumper and man was it great! i could almost ride with one hand.. super stable front steering, front wheel never had a hint of washing out.. i think i need that... i need the rear end to slide out first.

    cant afford the new 27.5 Anthem
    thanks for sharing Jaz !
    Um, yeah I'll take that. Thanks.

    Slackening the HTA I think might take the edge off, but that's not all that is going on with a bike. And yes, a 29er is much more stable and has much more traction. You might find it much to your liking.

    What year is your Trance. All the 26" Trances I know of have 69.5 degree HTA, and don't squeek. And I work on them. I'd like to think it's because I work on them. But I actually know for a fact that's not really true.

    You don't live anywhere near TN do you? I'd love to take a look at your ride and see what's going on. At this point I don't think you need a race bike. You need a bike that is light, stable, and that you are able to stick the front end.

    Off the the top of my head here are some thoughts your last paragraph brought to mind. 1) When's the last time the suspension was serviced? 2) Have you ever had you suspension setup, even just to a basic base line? 3) Just how old is this thing? 4) what are you running for tires. Something aggressive and wider in the front, or even going a bit narrower in the back might give you a better balance feel, in that the rear tire breaks loose sooner giving you the hint that the front may not be far behind. 5) Have you ever been properly fit to the bike?

    I am a 27.5" guy. But having watched and actually sold many 25.7 and 29er sport level hard tails, I know it is all about personal preference. You sound like you might really like a 29er. But I don't know anything really, without you walking into the shop I work at, and working with you.

    Yeah, not many of us can. Personally the new carbon XTC 27.5s make me drool pretty hard.

    Just hoping I'm actually helping. It can be a fine line sometimes.

  14. #14
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    For the record, only looking at the original post, without being given specific course requirements or features, I'd have selected the Orange frame precisely for it's in-between status where it should "do everything well" ...but then Jaz and I are friends, and a little bit old school. Or skool. Or however the cool kids spell it these days. Can kids still spell?

  15. #15
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    How much fork travel on each?

    On the majority of my trails, with my preferences and experiences... I've found 68 HA to be too slow, and 71 HA too steep for my liking. I also prefer 120mm of fork travel, so I would narrow my choices by the bike that comes out with 69-70 HA with a 120 fork. Then compare other numbers from there.

    If I assume they all come with 100mm forks... I'd probably go with the Orange frame and add a 120mm fork. If I had to keep the 100mm fork, I'd go with the Black or White frame. Probably the Black frame.

    my opinionated and basically worthless 2

  16. #16
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    Would you be willing to share the actual bikes behind those numbers? It would be really interesting to see how our perceptions map to the real bikes!

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