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Comparison of Dual-Tube vs Mono-Tube Frame Deflection

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    Comparison of Dual-Tube vs Mono-Tube Frame Deflection

    Watched this video, quite interesting.

    http://www.youtube.com/watch?v=BgtcAI08v3Y

    Notice the color, also quite interesting.

    Life is meaningles, though you create the purpose.sigpic

    #2
    But the Aero T's frame isn't deflecting. The Aero Z's footrest is displaced backwards.

    Comment


      #3
      i have the tilite ttc. it's a twin tube design and i have noticed how much better it feels vs monotube. over 10yrs old and still going!
      "Smells like death in a bucket of chicken!"
      http://www.elportavoz.com/

      Comment


        #4
        Thanks for the video, it's great.

        I don't interpret the colors same as you do, maybe some mechanical engineer could help but it seems to me that the color scale represents the force applied to the frame: red is the highest where the bump force is applied and blue is the lowest.

        The Aero T design distributes more the forces than the Aero Z which is a great thing as it avoids stressing and flexing one part in particular.
        My TR3

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          #5
          You might interpret the Z's flex as a shock absorber. The T hits with the same impact.
          I have had periodic paralysis all my life. I lost my ability to walk in 2011 beginning with a spinal block, which was used for a hip fracture caused by periodic paralysis.

          Comment


            #6
            You're interpreting the colors incorrectly. The AeroZ frame is built to flex and therefore the force of the impact is isolated closer to a single point. The AeroT frame is a box-frame design where the flex is more evenly distributed throughout the chair and therefore force will be spread out over more of the frame. Thats why there are warm colors spread out over more of the AeroT frame.

            The important thing to take away from the video is that the AeroT frame flexes less under impact and is, therefore, a more rigid frame.
            Last edited by brian; 12 Apr 2013, 9:55 AM.

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              #7
              So from my point of view, sitting in one chair or the other as it hits that obstacle, what is the difference? Is the dual-tube better able to keep rolling over and past that obstruction? Am I getting more of a physical shock if the chair flexes less? I'm not understanding what the point of this video is, if it's meant to be anything beyond "Aero-T frame is stronger than Aero-Z frame", which I wouldn't have thought was controversial enough to warrant a video? Is it a durability issue?

              Comment


                #8
                I think not many daily user will get those 100 lb impact.

                Deflection might cause frame fatigue, but for daily open frame chair, who is really going to knock themselves that hard? 100lb? It might throw ourselves out from the chair.

                Further more wheelie will help to avoid some obstacles.
                Life is meaningles, though you create the purpose.sigpic

                Comment


                  #9
                  You're right, but there are people who will. I'm sure I do. Not often, but enough to matter.

                  If I'm trying to get up a big curb and I charge at it and don't get the front end up high enough that's a pretty heavy collision. When I'm using my ski poles in the streets I'm traveling pretty fast and have been known to hit a pothole. Or when Axle gets pulled by his dog at 30mph anything he hits will result in an impact with enough force to block out the sun.

                  100lbs is an extreme test. No, it doesn't happen every day, but when it does It'd be glad to know my frame is built to take it.

                  Comment


                    #10
                    Originally posted by brian View Post
                    You're right, but there are people who will. I'm sure I do. Not often, but enough to matter.

                    If I'm trying to get up a big curb and I charge at it and don't get the front end up high enough that's a pretty heavy collision. When I'm using my ski poles in the streets I'm traveling pretty fast and have been known to hit a pothole. Or when Axle gets pulled by his dog at 30mph anything he hits will result in an impact with enough force to block out the sun.

                    100lbs is an extreme test. No, it doesn't happen every day, but when it does It'd be glad to know my frame is built to take it.
                    Yes, always looks for beyond safe level.
                    Life is meaningles, though you create the purpose.sigpic

                    Comment


                      #11
                      Originally posted by nonoise View Post
                      You might interpret the Z's flex as a shock absorber. The T hits with the same impact.
                      'Cept aluminum doesn't have 'memory', or damping. Every time it bends, even a little, it micro fractures. It's not cold deformable, without compromising it's mechanical properties. (Not true of all alloys, E.g. You can cold bend a Ti tube back and forth (within its limits) and it'll won't change, even microscopically!)
                      "I have great faith in fools; self-confidence my friends call it." - Edgar Allen Poe

                      "If you only know your side of an issue, you know nothing." -John Stuart Mill, On Liberty

                      Comment


                        #12
                        Originally posted by DaleB View Post
                        'Cept aluminum doesn't have 'memory', or damping. Every time it bends, even a little, it micro fractures. It's not cold deformable, without compromising it's mechanical properties. (Not true of all alloys, E.g. You can cold bend a Ti tube back and forth (within its limits) and it'll won't change, even microscopically!)
                        It would be interesting to see a deflection comparison video between one of their titanium open frame chairs (ZR, ZRA) and the aluminum Aero T. No doubt they've already done the tests and have the data.
                        stephen@bike-on.com

                        Comment


                          #13
                          Originally posted by QTiPi View Post
                          So from my point of view, sitting in one chair or the other as it hits that obstacle, what is the difference? Is the dual-tube better able to keep rolling over and past that obstruction? Am I getting more of a physical shock if the chair flexes less? I'm not understanding what the point of this video is, if it's meant to be anything beyond "Aero-T frame is stronger than Aero-Z frame", which I wouldn't have thought was controversial enough to warrant a video? Is it a durability issue?



                          It's mostly a marketing issue. Gotta sell those chairs.

                          "I have great faith in fools; self-confidence my friends call it." - Edgar Allen Poe

                          "If you only know your side of an issue, you know nothing." -John Stuart Mill, On Liberty

                          Comment


                            #14
                            Originally posted by stephen212 View Post
                            It would be interesting to see a deflection comparison video of one of their titanium open frame chairs (ZR, ZRA) and the aluminum Aero T. It's probably a safe assumption that they've already done the tests and have the data.

                            Hmmm...I wonder what their motivation for doing that would be? It would help us, as users, I can imagine. We need a IIHS for wheelchairs, smashing wheelchairs to test their real world limits! I'll volunteer to be the Head Smasher What's In-Charge!

                            "I have great faith in fools; self-confidence my friends call it." - Edgar Allen Poe

                            "If you only know your side of an issue, you know nothing." -John Stuart Mill, On Liberty

                            Comment


                              #15
                              The graphics of the video are more than a little suspect. The deflection of the Aero Z is .635" but the graphic grossly exaggerates the degree of travel. Consider that the frame tube diameter is 1.25"; the deflection shown is greater than the 1.25".
                              stephen@bike-on.com

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