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Thread: Reality check!

  1. #1
    STG
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    Reality check!

    Davide said it best. (latest post another thread) "Small step backwards"


    HL has proved itself over the last twenty years (recent Mountain biking action comparing designs). Acutually, both have been out there for a number of years, with little debate over the superior attributes of HL.

    Now, suddenly because Dave Turner produces a frame with pivot on seat stay, all is better? Don't get me wrong, "I'm a Turner groupy" but, his cult following can't protect him from physics.

    Dave did a fine job with TNT design! Compensating for design inherant shortcomings. Add, the fact that shock design has jumped lightyears ahead, it's easy to be confused. After all we are talking very small changes.

    Bottom line: TNT's design is a near (1mm) bullseye. And applied to the Six pac/RFX format the debate has merit! One could argue that TNT designs does somethings better in the freeriding format. (pro's and cons to every design)

    Where, there should be little debate "endurance field." While the TNT flux is no slouch
    and comes very close to the performance of HL, I think Maxwell Smart said it best "Missed it by that much" in this case 1mm.

  2. #2
    The Ancient One
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    Quote Originally Posted by STG
    Davide said it best. (latest post another thread) "Small step backwards"


    HL has proved itself over the last twenty years (recent Mountain biking action comparing designs). Acutually, both have been out there for a number of years, with little debate over the superior attributes of HL.

    Now, suddenly because Dave Turner produces a frame with pivot on seat stay, all is better? Don't get me wrong, "I'm a Turner groupy" but, his cult following can't protect him from physics.

    Dave did a fine job with TNT design! Compensating for design inherant shortcomings. Add, the fact that shock design has jumped lightyears ahead, it's easy to be confused. After all we are talking very small changes.

    Bottom line: TNT's design is a near (1mm) bullseye. And applied to the Six pac/RFX format the debate has merit! One could argue that TNT designs does somethings better in the freeriding format. (pro's and cons to every design)

    Where, there should be little debate "endurance field." While the TNT flux is no slouch
    and comes very close to the performance of HL, I think Maxwell Smart said it best "Missed it by that much" in this case 1mm.
    I pretty much agree with what you're saying, but you're putting too much emphasis on the 1mm thing. If it was only a matter of that tiny difference in axle path, then the two bikes, even under pure theoretical analysis, as opposed to riding impression, would behave almost exactly the same.

    But braking performance depends on both axle path and the extent to which the axle and caliper carrying link rotates with respect to the main frame. That amount is determined by the location of the pivot or IC. This is a noncontroversial point, agreed upon by all vehicle suspension experts.

    As for pedaling, the latest thinking in motorcycle dynamics says that the exact location of the pivot or IC also matters, not just axle path. But here the difference only manifests itself when traction is momentarily lost. Basically the TNT design would tend to compress more at that instant. Since on a mountain bike if you don't almost immediately regain traction during a climb you're going to stall out, the less movement of the suspension at that moment, the better.
    "Don't criticize what you can't understand."

  3. #3
    www.derbyrims.com
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    Quote Originally Posted by Steve from JH
    I pretty much agree with what you're saying, but you're putting too much emphasis on the 1mm thing. If it was only a matter of that tiny difference in axle path, then the two bikes, even under pure theoretical analysis, as opposed to riding impression, would behave almost exactly the same.

    But braking performance depends on both axle path and the extent to which the axle and caliper carrying link rotates with respect to the main frame. That amount is determined by the location of the pivot or IC. This is a noncontroversial point, agreed upon by all vehicle suspension experts.

    As for pedaling, the latest thinking in motorcycle dynamics says that the exact location of the pivot or IC also matters, not just axle path. But here the difference only manifests itself when traction is momentarily lost. Basically the TNT design would tend to compress more at that instant. Since on a mountain bike if you don't almost immediately regain traction during a climb you're going to stall out, the less movement of the suspension at that moment, the better.
    The shock leverage rate is the only noticeable ride difference between Turner TNT "faux-bar" and the FSR type designs. The TNT has more rising rate shock linkage. If using the same shock without adjusting for the leverage difference as tested by Davide will bounce more on deeper hits and produce worse traction. Some damping adjustment or mods to produce more digressive compression damping by PUSH or other shock tuners would virtually eliminate the noticeable difference Davide observed. (I refrained from commenting on Davide's post due to the pure observations otherwise posted there.)

    And Steve is technically correct about the IC position mattering for pedaling, there are friction and inertia factors of the whole floating link system that swing about the IC. And a "faux-bar'" rear link as close as the TNT to a floating link arrangement has virtually the same friction and inertia differences about it's near identical IC mapping. No honest expert rider could tell any difference. Machine readings of power and efficiency differences would only have the bias of the human readers to find differences. Bicycle building experts all agree (except Ellsworth, although his engineering expertise is very questionable) that path is the only noticeable ride time difference other than friction (including damping) and inertia effects.

    Copied from Davide's post:
    - Traction. The TNT performs similarly to the Horst when climbing not-technical sections (where by non-technical I define, roughly, a trail with less then 3" obstacles). However the Horst performs noticably better on more technical climbs. Put sizable obstacles on your path (anything where you have to lift the front wheel and hang on, 4-24") and my Horst with PUSH/RP3 finds traction wonderfully: it is the best feature of the my bike, I can go on obstacles that used to be impossible with ease. This is less so with the TNT, the deepest the rear goes in its travel (i.e. the highest the obstacle) the "skittish" the bike reacts. It just does not have the same "roll-over-anything" feel of the Classic. Note that here the best performance (for both bikes) is achieved with my RP3/PUSH in the soft (downhill) position. ADVANTAGE: CLASSIC.



    - ray

  4. #4
    My cup runneth over
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    Quote Originally Posted by STG
    Davide said it best. (latest post another thread) "Small step backwards"


    HL has proved itself over the last twenty years (recent Mountain biking action comparing designs). Acutually, both have been out there for a number of years, with little debate over the superior attributes of HL.

    Now, suddenly because Dave Turner produces a frame with pivot on seat stay, all is better? Don't get me wrong, "I'm a Turner groupy" but, his cult following can't protect him from physics.

    Dave did a fine job with TNT design! Compensating for design inherant shortcomings. Add, the fact that shock design has jumped lightyears ahead, it's easy to be confused. After all we are talking very small changes.

    Bottom line: TNT's design is a near (1mm) bullseye. And applied to the Six pac/RFX format the debate has merit! One could argue that TNT designs does somethings better in the freeriding format. (pro's and cons to every design)

    Where, there should be little debate "endurance field." While the TNT flux is no slouch
    and comes very close to the performance of HL, I think Maxwell Smart said it best "Missed it by that much" in this case 1mm.
    Turner groupy no-nos :
    Quoting bike magazine reviews to make your point (common faux-par - don't feel bad!)
    Theoretical points only, no personal ride time reviews (also a common faux-par - but unforgiveable!)

    Groupy/cult membership application: ***DENIED***

  5. #5
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    Quote Originally Posted by rmac

    Turner groupy no-nos :
    Quoting bike magazine reviews to make your point (common faux-par - don't feel bad!)
    Theoretical points only, no personal ride time reviews (also a common faux-par - but unforgiveable!)

    Groupy/cult membership application: ***DENIED***

    I can't believe I just read a thread where Davide was quoted TWICE, and not ironically. Strange days here on the forum. Lately, there have been lots of threads started with very questionable motives. Maybe it's a conspiracy.

  6. #6
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    Do you have a point?

    I find it interesting that the most recent "anti TNT" posts come from people that joined MTBR that very same day. What a coincidence

    I have tested TNT vs HL on my Spot. I wanted to be able to tell a difference. I was completely skeptical about TNT. You know what? I couldn't tell the difference.

    Maybe the HL is better than TNT.... on paper. Very few people that I know ride technical drewings, although after reading a few of these posts.... I wonder

    I think that you and other posters are completely missing the point. All that matters is.... How do TNT Turner bikes stack up against the competition? Do a comparison. Ride and compare.

    Would you buy a competitor's HL bike over a Turner TNT if the TNT rode better?

    Make a comparison that can have some connection with reality. TNT rides better than the old HL (XCE, Spec Ed). Turner is not going back to the HL. Get used to it. If Turner wanted to use the HL, the license fee is cheap.... around $6, I believe.

  7. #7
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    Quote Originally Posted by DLine
    questionable motives. Maybe it's a conspiracy.
    Smells like TE

    It must be humiliating for TE to find out that after he refused to renew ICT for Turner, Turner does even more business with a single pivot design.

    I love the irony.

  8. #8
    STG
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    Senitive spot

    WOW: I hit a sensitive spot?

    New to this forum thing: I keep my comments general to avoid personal bias. (Experience level, riding style, Height, weight, riding conditions, trail conditions, etc...) Numbers do not lie.

    But, “When I ride bike(s) with pivot in this location I feel the design steals a little energy from me vs. HL” It is that simple.

    Conspiracy? "You guys are not too protective"

    I'm not bashing TNT design? My first thread I said it may do some things better! IE. Pop's wheelies better. However, as it pertains to x-country seen, I remain stead fast that flux HL has no equal.

    Steve and Ray: Point(s) taken/ I learned something. Thanks!

    D line and rmac "Groupie/cult membership application: ***DENIED*** "

    Touché', you got me!

    However, FYI: Personal use/ three DH's, two 5 spot's, two xce’s, two rfx's, one flux later
    I expect my membership card ASAP.

    Ride hard, take lots of chances!

  9. #9
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    You know what?

    Quote Originally Posted by Blue Shorts
    I find it interesting that the most recent "anti TNT" posts come from people that joined MTBR that very same day. What a coincidence

    I have tested TNT vs HL on my Spot. I wanted to be able to tell a difference. I was completely skeptical about TNT. You know what? I couldn't tell the difference.

    Maybe the HL is better than TNT.... on paper. Very few people that I know ride technical drewings, although after reading a few of these posts.... I wonder

    I think that you and other posters are completely missing the point. All that matters is.... How do TNT Turner bikes stack up against the competition? Do a comparison. Ride and compare.

    Would you buy a competitor's HL bike over a Turner TNT if the TNT rode better?

    Make a comparison that can have some connection with reality. TNT rides better than the old HL (XCE, Spec Ed). Turner is not going back to the HL. Get used to it. If Turner wanted to use the HL, the license fee is cheap.... around $6, I believe.

    Your post was one of the ones that made me take the plunge on a TNT spot. I remember how skeptical you were so it was reassuring to see that you couldn't find a difference even though you expected to find one. I hope I'm in the same boat.

    I'm gonna get a little teary eyed when I trade in my old faithful XCE though. She's been the best bike I've ever owned by a _large_ margin.

    Dave

  10. #10
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    Quote Originally Posted by STG
    Davide said it best. (latest post another thread) "Small step backwards"


    HL has proved itself over the last twenty years (recent Mountain biking action comparing designs). Acutually, both have been out there for a number of years, with little debate over the superior attributes of HL.

    Now, suddenly because Dave Turner produces a frame with pivot on seat stay, all is better? Don't get me wrong, "I'm a Turner groupy" but, his cult following can't protect him from physics.

    Dave did a fine job with TNT design! Compensating for design inherant shortcomings. Add, the fact that shock design has jumped lightyears ahead, it's easy to be confused. After all we are talking very small changes.

    Bottom line: TNT's design is a near (1mm) bullseye. And applied to the Six pac/RFX format the debate has merit! One could argue that TNT designs does somethings better in the freeriding format. (pro's and cons to every design)

    Where, there should be little debate "endurance field." While the TNT flux is no slouch
    and comes very close to the performance of HL, I think Maxwell Smart said it best "Missed it by that much" in this case 1mm.
    I think you swallowed the HL pill. It isn't a big deal but it's something for the marketing brigade and technoheads to get stuck into. There are inherent shortcomings of all designs, including the beloved HL. Bottom line is that it seems to have made very little difference to the ride and handling. The last of the HL evangelists will continue to insist that there is a tiny difference (it used to be a massive night and day difference before TNT came along).

  11. #11
    Daniel the Dog
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    DT fed us the pill

    Quote Originally Posted by uktrailmonster
    I think you swallowed the HL pill. It isn't a big deal but it's something for the marketing brigade and technoheads to get stuck into. There are inherent shortcomings of all designs, including the beloved HL. Bottom line is that it seems to have made very little difference to the ride and handling. The last of the HL evangelists will continue to insist that there is a tiny difference (it used to be a massive night and day difference before TNT came along).
    This is something Turner blew the trumphet on for years. We didn't make it up. Either DT was marketing and BSing or HL means something. You decided?

    Jaybo

  12. #12
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    Quote Originally Posted by Jaybo
    This is something Turner blew the trumphet on for years. We didn't make it up. Either DT was marketing and BSing or HL means something. You decided?

    Jaybo
    There's nothing wrong with the HL concept. It's just a classic 4-bar linkage, used in all sorts of engineering applications. My point is that it doesn't give any real advantage over a well designed single pivot. There are many outstanding bikes that do not use a HL, including the Turner TNT bikes themselves. Turner had a great bike with excellent geometry based on the HL concept, so why not blow his own trumpet? But it doesn't mean that HL is the only way you can design a good bike. HL evangelists believe it is the Holy Grail and NOTHING else can come close. Truth is, there are many ways of achieving a really good handling bike. Personally I like the simplicity of the "Faux Bar" with the wheel attached directly to the chainstay and a rocker actuated shock i.e Kona, Ventana and now Turner. But that's not to say I think all "Faux Bar" bikes handle the same. There are loads of other factors to consider eg. veritcal, lateral and torsional compliance, basic frame geometry, shock leverage ratio, bearing friction and damping. It's the sum of all these parts that make an outstanding design. Turner bikes are clearly outstanding, with or without the HL.

  13. #13
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    Thanks for the vote of confidence.

    The results blew me away, too. I was positive that I would be able to easily tell that TNT was inferior. I was obviously wrong. Enjoy the bike!!!!!!!!!

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