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    #31
    Alright. Worked on the chair today and dropped the dump completely. Put the COG all the way back to make it less tippy. My posture has changed completely. It's amazing how things are starting to look up. Only problem is the chair is still quite tippy. If I push to chair up steep ramps or too hard the casters will still pop off the ground. Still using the actaback as of now and realize I need a back that is much more contoured, I think.. I called a local DME who is going to get me a demo of the varilite icon mid back. It looks to be a good backrest. I really liked its adjustability in the video I watched. Still, it's too tippy for my tastes. Anything else I can adjust to fix this?

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      #32
      The tippy-ness is more an issue of back angle than contour. Imagine trying to drive a car with a seat that's reclined too much. Sit the seat up a little and all of a sudden it becomes much more functional. Same issue here.

      While you're waiting to try another back, try adjusting the angle of your back posts so you can sit up a little straighter.

      Glad things are brightening up for you.

      Comment


        #33
        Hey BTB, I know less than diddly about rugby chairs, and obviously it's not an apples-to-apples comparison, but looking at your avatar photo I was wondering if there are aspects of its specs/dimensions that can you apply toward your everyday. Anything to glean there?
        stephen@bike-on.com

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          #34
          Originally posted by stephen212 View Post
          Hey BTB, I know less than diddly about rugby chairs, and obviously it's not an apples-to-apples comparison, but looking at your avatar photo I was wondering if there are aspects of its specs/dimensions that can you apply toward your everyday. Anything to glean there?
          I don't know the specs. It's not even a chair I use anymore. My team is letting me borrow a chair until the CAF grants open up again and I can buy my own.

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            #35
            Originally posted by stephen212 View Post
            Hey BTB, I know less than diddly about rugby chairs, and obviously it's not an apples-to-apples comparison, but looking at your avatar photo I was wondering if there are aspects of its specs/dimensions that can you apply toward your everyday. Anything to glean there?
            Stephen is on to something here - rugby. Are you guys practicing/meeting often? If so check out what's working for your teammates and see if you can apply it to your setup. There's nothing like seeing it in person.

            You'll get there.

            You said in another thread your goal is to end up with a lower backrest to achieve a more efficient push. Great idea. But gently. I lowered mine in increments dropping about 1/2" a week until I found where I wanted it.

            Another thing I thought of reading through here tonight was the dump. When I first started researching on here 3 years ago I thought more was better. Not necessarily so. Anything more than 4" is too much for anyone around 6-foot tall. It makes transferring out of a real bitch and that is a lot of shear forces on the old butt-skin. Looking again at your chair I don't think it's possible to adjust it to even 4", so no worries here. (just an FYI, YMMV)

            Footrest - I do recall placing skateboard grip tape on my angle adjustable footplate when I had a ZRa. Seemed to work great at the time, but looking back I think attempting to correct the issues through adjustments would be a better approach.

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              #36
              Varilite Icon demo

              Hi BTB- We can work with Stalls and our local rep to get you a demo. Send me an email with your specific needs and I will get the ball rolling.

              Karyn Abraham
              karyn.abraham@varilite.com
              Last edited by VARILITE team member; 5 Feb 2013, 12:26 PM. Reason: Wrong email address...

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                #37
                So I adjusted my back angle to about 90 degrees so I'm sitting more upright and still the chair is too tippy. I looked up my specs and my COG is 5.5", is this normal? Went to lunch yesterday and couldn't get up a ramp by myself. Starting to wonder if the therapist wrote down the wrong specs for the chair. What's left to do? Varilite is getting me a demo of the icon backrest, will that change the tippyness factor since the backrest can be adjusted in so many ways? Would it be worth getting a new frame with a different COG?

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                  #38
                  the chair may have been sent from the factory with 5.5" COG but because it is infinitely adjustable it doesn't matter. From the picture you supplied it appears somewhere along the lines it has been adjusted. I see a COG of almost 0 in the photos.

                  Can you post another side view of the chair, preferably with you in it, now that you have adjusted the dump and backrest angle? It may help...

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                    #39
                    5.5" axle position! Yikes, that is very far forward, IMO.

                    Moving it all the way back 5.5" also lowered the rear, a bit.

                    Perhaps, dropping the front an equal amount may help, or lifting the rear back up just a smidge.

                    With 0" axle position and a 90deg back I'm personally stumped as to why you still feel tippy.

                    Mass must still be, somehow, more rear than forward, akaik.

                    Tough one.
                    "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

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                      #40
                      Originally posted by BTB View Post
                      So I adjusted my back angle to about 90 degrees so I'm sitting more upright and still the chair is too tippy. I looked up my specs and my COG is 5.5", is this normal? Went to lunch yesterday and couldn't get up a ramp by myself. Starting to wonder if the therapist wrote down the wrong specs for the chair. What's left to do? Varilite is getting me a demo of the icon backrest, will that change the tippyness factor since the backrest can be adjusted in so many ways? Would it be worth getting a new frame with a different COG?

                      90deg to the frame, or the floor?
                      "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


                        #41
                        Originally posted by BTB View Post
                        So I adjusted my back angle to about 90 degrees so I'm sitting more upright and still the chair is too tippy. I looked up my specs and my COG is 5.5", is this normal? Went to lunch yesterday and couldn't get up a ramp by myself. Starting to wonder if the therapist wrote down the wrong specs for the chair. What's left to do? Varilite is getting me a demo of the icon backrest, will that change the tippyness factor since the backrest can be adjusted in so many ways? Would it be worth getting a new frame with a different COG?
                        COG is 5.5" is a LOT! But rather than assume it's correct, determine the actual COG, which is the horizontal distance measured from the front of the back post to the center of the axle.

                        Regardless, you should begin to start moving the COG back. (My COG is 4". Browse through the CAD Repository, I doubt you'll find many if any COGs much greater than 4.5".)
                        stephen@bike-on.com

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                          #42
                          ..am now thinking solid backrest position may be playing a role. check out -scott-'s post #22 in this thread. Have whoever install the demo Varilite Icon backrest in the basic configuration.

                          Comment


                            #43
                            If I recall, the ActaBack was slightly behind the back posts and adjusting its hardware to move it forward should help. It is a fairly heavy back, however, and its weight may be contributing to the the tendency for the chair to tip back.

                            Comment


                              #44
                              Originally posted by stephen212 View Post
                              COG is 5.5" is a LOT! But rather than assume it's correct, determine the actual COG, which is the horizontal distance measured from the front of the back post to the center of the axle.

                              Regardless, you should begin to start moving the COG back. (My COG is 4". Browse through the CAD Repository, I doubt you'll find many if any COGs much greater than 4.5".)
                              Given what SCI_OTR observed about the Acta, maybe the position of the back face to axle would yield something closer to actual?
                              "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


                                #45
                                BTB – Like Tooley sez, updated side shots of you in your chair will be extremely helpful at this point. Take them down low, squarely off the center of the axle so we can accurately see your present backpost angle, degree of dump, COG/axle set, seat depth and normal foot placement.

                                Stow your camera-side arm forward out of the way of the seat back post on one shot, hang your arm loosely straight down along the wheel spokes on another to show where your fingertips naturally fall in relation to the axle. Take another pair of squarely fore & aft shots while your at it.

                                Nit-picky suggestion from an interested observer.

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