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  1. #1
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    Ok, I need help...what the heck am I looking at? (modern geo)

    So, I'm no stranger to bikes. I've designed them, built them, fixed them, raced them, sold them etc... Buuuuut! I rode pretty much exclusively road until 2015 and now I'm dirt only. I like my XC bike (29er)...it's great, mostly. I'd really like to get a new frame next year and would love to explore something a little more in a modern geo hardtail. I'm on the Front Range of Colorado and ride lot's in Boulder county FWIW. So, you know...a little XC, bike parks and some techy stuff (no lifts/shuttle runs etc... though). Anyway, feedback on something in the 68hta range? Looking to increase the "fun" factor on rides and my XC bike, even with a dropper is just really twitchy and not much fun on "bermy" track with opportunities for a little air. Also, should I be looking to maintain my general position? I'm presuming a shorter stem will be in order for proper handling. The reach on my XC bike is approx. 430mm w/an EFF top tube of 615mm. I'm not "stuck" on 29er, although I'm very used to the wheel size. I can research frames all day, just like to hear from some folks who have some miles on these bikes. TIA.
    The member formerly known as Redtires....

  2. #2
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    Your post is really open ended, so here's some vague thoughts...

    Mountain bikes are designed for handling first, then put the rider in a spot where he can pedal well. It makes it so ETT and head angle is not very useful- much better to substitute reach and front center.

    A short stem combined with a slacker head angle is just a way to preserve the steering feel while lengthening front center.

    You don't really lose any pedal performance by pushing the front center out in front of you until you have to start pushing the saddle forward to keep the saddle-bar distance manageable (which it doesn't sound like you'll have to concern yourself about). A longer front center will be happier at higher speed, which will want heavier bits to keep it together. That basically covers the entire hardtail market- how long is the front center, what parts are appropriate for that length? The rest is just determining its personality.

    Hardtails get steeper when they sag, so a slacker hardtail will feel a little steeper than an equivalent suspension bike.
    "Things that are complex are not useful, Things that are useful are simple."
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  3. #3
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    go demo this, its awesome https://www.santacruzbicycles.com/en-US/chameleon

    i demoed it with 29" wheels on it. omg it loves to haul ass. its built really nice too

    heres a good vid review, i agree with everything he says

    https://www.youtube.com/watch?v=HjaMLm8qes0

  4. #4
    WillWorkForTrail
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    Quote Originally Posted by scottzg View Post
    Your post is really open ended, so here's some vague thoughts...

    Mountain bikes are designed for handling first, then put the rider in a spot where he can pedal well. It makes it so ETT and head angle is not very useful- much better to substitute reach and front center.

    A short stem combined with a slacker head angle is just a way to preserve the steering feel while lengthening front center.

    You don't really lose any pedal performance by pushing the front center out in front of you until you have to start pushing the saddle forward to keep the saddle-bar distance manageable (which it doesn't sound like you'll have to concern yourself about). A longer front center will be happier at higher speed, which will want heavier bits to keep it together. That basically covers the entire hardtail market- how long is the front center, what parts are appropriate for that length? The rest is just determining its personality.

    Hardtails get steeper when they sag, so a slacker hardtail will feel a little steeper than an equivalent suspension bike.
    I think the general population is a little too quick to write off ETT as an effective means of fit. We've simply evolved into an era where it's only one part of the consideration. ETT is still important for a seated fit measurement, while Reach is a better indicator of standing fit (ie: descending). Again, taking any of these numbers in isolation is a mistake, but ignoring them can be perilous as well. Otherwise, I think this is pretty solid advice.

    That said, if you want a specific bike recommendation, I'd look at something from some guys that know a little about front range riding. I know it looks more aggressive than you're talking about, but you live close enough you should be able to demo a Guerrilla Gravity Pedalhead from headquarters. I think if I was looking for a new hardtail that would be my starting point anyhow.

  5. #5
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    Quote Originally Posted by scottzg View Post
    Your post is really open ended, so here's some vague thoughts...

    Mountain bikes are designed for handling first, then put the rider in a spot where he can pedal well. It makes it so ETT and head angle is not very useful- much better to substitute reach and front center.

    A short stem combined with a slacker head angle is just a way to preserve the steering feel while lengthening front center.

    You don't really lose any pedal performance by pushing the front center out in front of you until you have to start pushing the saddle forward to keep the saddle-bar distance manageable (which it doesn't sound like you'll have to concern yourself about). A longer front center will be happier at higher speed, which will want heavier bits to keep it together. That basically covers the entire hardtail market- how long is the front center, what parts are appropriate for that length? The rest is just determining its personality.

    Hardtails get steeper when they sag, so a slacker hardtail will feel a little steeper than an equivalent suspension bike.
    It was open ended on purpose (motivational interviewing 101). And you're right regarding sag, stem/hta for handling, etc... I completely get the "physics" behind the design. The last part of the post was asking feedback regarding ride quality vs. the overall design. Don't get me wrong, I appreciate you jumping into the thread and I'm sure, in my normal fashion, I'm overthinking this. I suppose a more narrow question is for those who have moved from a traditional XC bike to more modern geo, how did you like the longer wheelbase, slacker front, etc???
    The member formerly known as Redtires....

  6. #6
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    Quote Originally Posted by Joe Handlebar View Post
    I suppose a more narrow question is for those who have moved from a traditional XC bike to more modern geo, how did you like the longer wheelbase, slacker front, etc???
    Oh. Well then we've spent like 15 years transitioning away from awful compromised road bike geometry, and we've finally gotten to where it should have been all along, and the most progressive designs are exploring compromise in the opposite direction. Modern progressive geometry is on point- better handling, no down side.


    Don't be afraid of an even longer front center than you're currently contemplating. Test some bikes.
    "Things that are complex are not useful, Things that are useful are simple."
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  7. #7
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    http://dirtragmag.com/review-canfield-brothers-epo/

    These guys make amazing bikes You'll find a lot of solid reviews on this frame. My bikes have been progressively more modern as I age and I am overwhelmed by the capabilities of the modern mtb. 15 years ago a dry leaf would pitch me Otb now it feels like a photo shoot every time I throw my leg over the bike. A bad photo shoot from a crappy magazine but you get the point.

    Sent from my SM-T550 using Tapatalk

  8. #8
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    Quote Originally Posted by scottzg View Post
    Oh. Well then we've spent like 15 years transitioning away from awful compromised road bike geometry, and we've finally gotten to where it should have been all along, and the most progressive designs are exploring compromise in the opposite direction. Modern progressive geometry is on point- better handling, no down side.


    Don't be afraid of an even longer front center than you're currently contemplating. Test some bikes.
    Well, now that's some interesting feedback. And right, XC bikes have always been pretty close to road bikes, which is a bit of why I was inquiring if folks were intentionally attempting to mimic riding positions from XC to longer bikes. Coming from road, and traditional XC, I tend to like to be rather stretched. I've seriously relaxed my "road" position over the last couple of years to be a little shorter and wider, higher bars. The first XC bike I'd had in years in this move from road to dirt included a fantastic 135mm stem and 56cm bars. It was a cool bike though, a Voodoo "something"....can't recall.
    The member formerly known as Redtires....

  9. #9
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    Quote Originally Posted by nauc View Post
    go demo this, its awesome https://www.santacruzbicycles.com/en-US/chameleon

    i demoed it with 29" wheels on it. omg it loves to haul ass. its built really nice too

    heres a good vid review, i agree with everything he says

    https://www.youtube.com/watch?v=HjaMLm8qes0
    That's a beautiful bike! As a frame, you could probably build a really solid 24-25lb rig. Thanks for that share!
    The member formerly known as Redtires....

  10. #10
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    Quote Originally Posted by Cotharyus View Post
    I think the general population is a little too quick to write off ETT as an effective means of fit. We've simply evolved into an era where it's only one part of the consideration. ETT is still important for a seated fit measurement, while Reach is a better indicator of standing fit (ie: descending). Again, taking any of these numbers in isolation is a mistake, but ignoring them can be perilous as well. Otherwise, I think this is pretty solid advice.


    I don't like ETT. It incorporates seat angle, which is basically meaningless unless you're quite tall (or it's wildly divergent). It ignores stem length, so it doesn't tell you how stretched out you'll be. It's all about the top half of the bike, so it doesn't imply how the bike handles. It has the same problem as Reach- change the stack height and the number changes while the fit doesn't. You don't even interact with the bike where ETT is measured, so your fit is only tangentially related to ETT. I think ETT is more useful as a tool to guide the buyer than any sort of fit tool, and frame designers aren't paying attention to ETT any more.

    Reach + front center + chainstay length will tell you who a frame fits, it's intended use, and how it needs to be ridden (for a given rider using an appropriate stem).

    ETT is less worthless for road bikes, but still not that great. At least head and seat angles are closer to parallel. It seems like for mountain bikes if it handles right you won't be too stretched out in the saddle anyway. Maybe that's my bias from being quite tall with an even longer wingspan, i dunno.

    Quote Originally Posted by Joe Handlebar View Post
    Well, now that's some interesting feedback. And right, XC bikes have always been pretty close to road bikes, which is a bit of why I was inquiring if folks were intentionally attempting to mimic riding positions from XC to longer bikes. Coming from road, and traditional XC, I tend to like to be rather stretched. I've seriously relaxed my "road" position over the last couple of years to be a little shorter and wider, higher bars. The first XC bike I'd had in years in this move from road to dirt included a fantastic 135mm stem and 56cm bars. It was a cool bike though, a Voodoo "something"....can't recall.

    The overall riding position on the best XC/Trail bikes isn't radically different from the hoods position on a road bike. A few tweaks here and there, but mtbs aren't chasing the last 5 watts of efficiency, and ultimately we're limited by cardio once we've adapted to a bike. Much larger gains to be had making the bike handle fantastically.

    Don't worry too much about your road/XC position and chase handling; your legs will adapt pretty quickly to most of what's out there. The trick is progressive modern bikes need to be ridden 'over the front' to handle right, and that's weird to someone with a road background.

    Test ride some bikes! Unfortunately it takes familiarity to recognize a good/bad design, and that's why we've been riding road inspired nonsense for so long.
    Last edited by scottzg; 11-02-2017 at 11:03 PM.
    "Things that are complex are not useful, Things that are useful are simple."
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  11. #11
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    This is kind of strange, I pretty much normally agree with you, but on this point, definitely not.ETT is such a waste of time sizing a bike properly if you cannot actually swing a leg over a bike. To me ETT is useless because despite all the various STA, a person is going to put their saddle where it needs to be relative to the BB (or at least that how I do it and how I feel it should be done), then from there you go about working out the rest of the cockpit fit and setup. I also feel STA really only tells you whether you're going to need a straight or offset post to get the saddle to your ideal position, relative to the BB, within about a 2-3 degree range.

    For me Reach and stack are definitely the main things to look at to really help determine a bikes fit. Reach for the real size of the bike and Stack to determine if the Reach between bikes is actually what the numbers say or greater/lesser - as in general a higher stack will give you greater reach and lower will decrease reach

    Quote Originally Posted by Cotharyus View Post
    I think the general population is a little too quick to write off ETT as an effective means of fit. We've simply evolved into an era where it's only one part of the consideration. ETT is still important for a seated fit measurement, while Reach is a better indicator of standing fit (ie: descending). Again, taking any of these numbers in isolation is a mistake, but ignoring them can be perilous as well. Otherwise, I think this is pretty solid advice.
    OP, you didn't mention what length stem or width bar you're running on your XC bike with 430mm Reach, that info would make a lot of difference in sizing for a modern oriented trail bike. If say you're currently running a 120mm stem and 685mm bar, then you could easily go to a Reach in the 450-470mm range, shorten your stem up 30-60mm and go for a wider bar and get a similar cockpit setup/fit.

    I'd also suggest that if you're not accustomed to "modern" geometry, that you try to get a test ride on one, as it will handle quite a bit different than your "XC" setup. For me, I'd also recommend going for something either steel or Ti to help make the rear end smoother if you're going to be riding more aggressive stuff, something like the new Karate Monkey or Kona Unit would give you something not as extreme as a lot of other newer designs rigid, and if you put a sus fork on them in the 120mm range, then you'd be in the 67-68* HTA range.
    One day your life will flash before your eyes, will it be worth watching??

  12. #12
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    Quote Originally Posted by LyNx View Post
    ...OP, you didn't mention what length stem or width bar you're running on your XC bike with 430mm Reach, that info would make a lot of difference in sizing for a modern oriented trail bike. If say you're currently running a 120mm stem and 685mm bar, then you could easily go to a Reach in the 450-470mm range, shorten your stem up 30-60mm and go for a wider bar and get a similar cockpit setup/fit.

    I'd also suggest that if you're not accustomed to "modern" geometry, that you try to get a test ride on one, as it will handle quite a bit different than your "XC" setup. For me, I'd also recommend going for something either steel or Ti to help make the rear end smoother if you're going to be riding more aggressive stuff, something like the new Karate Monkey or Kona Unit would give you something not as extreme as a lot of other newer designs rigid, and if you put a sus fork on them in the 120mm range, then you'd be in the 67-68* HTA range.
    Good point, I didn't put that in there. I'm currently running a 90mm stem with 720 bars. Now, I WAS running a longer stem (100/110 depending) but I brought it back in order to see if I could get a little better "trail feel" (?) vs. a stretched out, short wheelbase, steep head angle ride. Back in the 80's and 90's trail riding was different. I'm really liking what is being built around me right now and it's not old school XC stuff. I'm just now starting to explore something for the spring, and I totally hear all of you saying do some test rides. I appreciate all the great info and feedback.
    The member formerly known as Redtires....

  13. #13
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    Ok, I need help...what the heck am I looking at? (modern geo)-overkill.png

    Here's my current frame. It's a trail hardtail built around a 130mm fork with fairly conservative modern geometry, and a conservative trail build at 29lbs for my 6'3, 215lb self. It would be a lighter frame with a lighter build if i wasn't such a reckless fatass, but that's what works.

    That geo doesn't really give up any climbing prowess for descending, or vice-versa; it's just somewhere in the range of 'good' for most situations. It's average geometry nowadays, which is pretty awesome since it was super extreme when i started doing my own frames 8 years ago.
    "Things that are complex are not useful, Things that are useful are simple."
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  14. #14
    WillWorkForTrail
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    Quote Originally Posted by LyNx View Post
    This is kind of strange, I pretty much normally agree with you, but on this point, definitely not.ETT is such a waste of time sizing a bike properly if you cannot actually swing a leg over a bike. To me ETT is useless because despite all the various STA, a person is going to put their saddle where it needs to be relative to the BB (or at least that how I do it and how I feel it should be done), then from there you go about working out the rest of the cockpit fit and setup. I also feel STA really only tells you whether you're going to need a straight or offset post to get the saddle to your ideal position, relative to the BB, within about a 2-3 degree range.

    For me Reach and stack are definitely the main things to look at to really help determine a bikes fit. Reach for the real size of the bike and Stack to determine if the Reach between bikes is actually what the numbers say or greater/lesser - as in general a higher stack will give you greater reach and lower will decrease reach
    I wouldn't say Reach and Stack aren't valid - they are. Read everything you quoted. The thing is, ETT isn't the ONLY effective means of fit - it's part of an equation for me. I know what the ETT/Reach/Stack are on what I ride now, and I know where that puts me in relation to the axles (front center/CS length) and what sort of characteristics to look for with given HTAs. To me it's about the whole picture, which is sort of a lesson I've learned slowly over the last 30 years. And that 30 year number is part of the problem for me. Before reach and stack became a thing, the only way I could tell what size bike might fit me was ETT numbers. Although there may be a way to remove it from my thought process when looking at bike fit, I'm not certain my brain isn't wired such that if I do, it will forever look like a puzzle with a piece missing.

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