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Thread: How much does a cantilever frame affect pushing efficiency?

  1. #11
    Quote Originally Posted by SCI_OTR View Post
    Just out of curiosity which is easier to perform a stable wheelie in?
    It's a slight apples-to-orange comparison at the moment because the Matrix back on my Halls is shortchanging my seat depth slightly. Presently the ZR2 is a little tippier, which I like. Otherwise I would say it's a draw between them.

    I really like the "bullet" caster housing on the TiLites. It feels more solid to me than the bearings-in-housing style on the Halls.

  2. #12
    Thanks for the info. I am asking as I'm thinking of getting a new chair. I currently have a titanium, thin diameter tubing, rgk with a box frame and I am thinking of getting a cantilever frame with 1.25" titanium tubing, a change from 26" wheels to 25" with the only other change in spec being the taper down to my footplate, which is staying the same width, being 2" wider at the top half to stop my legs rubbing when leaning forward to do pressure reliefs which makes my knees splay out.

    I'm also thinking of getting the carbon fibre seat pan instead of the sling seat. Does the carbon fibre seat pan only add any noticeable efficiency, I've read it acts as subtle suspension when going over bumps too but would this be noticeable on cushions with a solid base ie a Jay 2?

    I did notice a difference comparing the 5x1"and 4x1.5" frogs legs casters, in a frogs legs fork using the the lower mount height to keep the front stf the same and the 4x1.5" did not roll as well. I'm trying to figure out if other changes would be as noticeable?

  3. #13
    Quote Originally Posted by stephen212 View Post
    It's a slight apples-to-orange comparison at the moment because the Matrix back on my Halls is shortchanging my seat depth slightly. Presently the ZR2 is a little tippier, which I like. Otherwise I would say it's a draw between them.

    I really like the "bullet" caster housing on the TiLites. It feels more solid to me than the bearings-in-housing style on the Halls.
    Agreed. I kind of see caster barrels as obsolete at this point.

    Not that you would particularly care, but so far no manufacturer has perfected a way to easily true the fork stems on an adjustable model and ensure it stays put after a sustaining a harder impact. TiLite's "six shooter" design will stay put, but making this adjustment is much more difficult than it seems.

    Although I have yet to tinker with it, Ki Mobilty's "Rack & Pinion" design looks promising.


  4. #14
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    Quote Originally Posted by rob1 View Post
    ... I am asking as I'm thinking of getting a new chair. I currently have a titanium, thin diameter tubing, rgk with a box frame and I am thinking of getting a cantilever frame with 1.25" titanium tubing, ... getting the carbon fibre seat pan instead of the sling seat. Does the carbon fibre seat pan only add any noticeable efficiency, I've read it acts as subtle suspension when going over bumps too but would this be noticeable on cushions with a solid base ie a Jay 2?
    I'm too new in a chair to compare different seat setups BUT – excepting a combination of physical needs that demands the give and sag and constant readajustment of a sling seat –I can't imagine anything more sensible than specking a new chair with a c/f seat pan or adding c/f/velcro strips ala Stephen212.

    I went with a Ti Composite (c/f) seat pan on my May/12 ZR, which is reinforced along the centerline by a composite fore and aft rib resting on a saddle post set upon the cross tube. Sitting directly on the pan is just like sitting on a barstool, so cushion (and perhaps a cantilever frame) is mostly all that will absorb what's between a rock and your hard place.

    Cushions are a whole other thing, very user-dictated, but in my case a 2" Stimulite Sport eats up vibrations and bumps just fine. Sitting immobile for up to three hours is comfortably comfortable.

    I would imagine the c/f strip configurations used by Stephen, toto and others, have a little more "give" than the Ti c/f pan and might be a better bet for certain other butts ... perhaps they'll chime in.

  5. #15
    Quote Originally Posted by rob1 View Post
    Thanks for the info. I am asking as I'm thinking of getting a new chair. I currently have a titanium, thin diameter tubing, rgk with a box frame and I am thinking of getting a cantilever frame with 1.25" titanium tubing, a change from 26" wheels to 25" with the only other change in spec being the taper down to my footplate, which is staying the same width, being 2" wider at the top half to stop my legs rubbing when leaning forward to do pressure reliefs which makes my knees splay out.

    I'm also thinking of getting the carbon fibre seat pan instead of the sling seat. Does the carbon fibre seat pan only add any noticeable efficiency, I've read it acts as subtle suspension when going over bumps too but would this be noticeable on cushions with a solid base ie a Jay 2?

    I did notice a difference comparing the 5x1"and 4x1.5" frogs legs casters, in a frogs legs fork using the the lower mount height to keep the front stf the same and the 4x1.5" did not roll as well. I'm trying to figure out if other changes would be as noticeable?
    Ah Ha! So you do have a pragmatic agenda.

    A couple things to note...

    A solid seat pan will raise your effective STF height by 1/4-1/2" so you will want to account for that in your specs if you go that route. I believe TexasWheelz discovered this the hard way when he first took delivery of his ZR2.

    Another thing to keep in mind is that FrogLegs suspension forks behave differently on a cantilevered frame than the do on a box frame. This has to do with the fact that the caster housing isn't buttressed by a lower frame rail. If you lean forward and do not take this into account, compression of the elastomer combined with a slight compression of the frame will cause the front end to dip forward. If you do not react quickly when this occurs, the result will frequently be a transfer transfer endo. Models that have ovalized tubing connecting the caster housing to the front frame will be less likely to do this.

    Of course, using the old school technique of reverse swiveling your forks can make he compression of the elastomer work in your favor.

    With the vast majority of the chairs I spec, a 4 or 5x1.4" soft roll will usually suffice. A standard bearing fork, SlipStream fork, or UniTine fork will perform better in most situations, gives your a slightly tighter swivel radius, and will be less-costly to maintain in the long run. FrogLegs forks combined with an adjustable angle footplate may be recommended if the user has severe spasms that tend to be triggered by vibration of rolling over rougher surfaces.


  6. #16
    Quote Originally Posted by nofuss View Post
    I'm too new in a chair to compare different seat setups BUT – excepting a combination of physical needs that demands the give and sag and constant readajustment of a sling seat –I can't imagine anything more sensible than specking a new chair with a c/f seat pan or adding c/f/velcro strips ala Stephen212.
    In order to increase the tautness of my adjustable tension by straps seat upholstery, before I put the sling over the straps, I wrap these Velcro One Wraps straps around the middle of each individual upholstery strap. They are thicker and have greater holding power than the less-expensive style of One Wraps (that are typically sold quantities of 50-100). These will hold and definitely make a difference.





    This heavier duty version is a relatively new product. I first discovered them at my local Lowes about a year ago.


  7. #17
    Quote Originally Posted by nofuss View Post
    I'm too new in a chair to compare different seat setups BUT – excepting a combination of physical needs that demands the give and sag and constant readajustment of a sling seat –I can't imagine anything more sensible than specking a new chair with a c/f seat pan or adding c/f/velcro strips ala Stephen212.

    I went with a Ti Composite (c/f) seat pan on my May/12 ZR, which is reinforced along the centerline by a composite fore and aft rib resting on a saddle post set upon the cross tube. Sitting directly on the pan is just like sitting on a barstool, so cushion (and perhaps a cantilever frame) is mostly all that will absorb what's between a rock and your hard place.

    Cushions are a whole other thing, very user-dictated, but in my case a 2" Stimulite Sport eats up vibrations and bumps just fine. Sitting immobile for up to three hours is comfortably comfortable.

    I would imagine the c/f strip configurations used by Stephen, toto and others, have a little more "give" than the Ti c/f pan and might be a better bet for certain other butts ... perhaps they'll chime in.
    Not to be pedantic, but the solid composite seat pan that TiLite offers is plastic, not carbon fiber. Not sure why it needs to be supported with a truss, but I have not had any need for additional support for either of my carbon fiber seat pans, one which came from DragonPlate, the other from a private carbon fiber fabricator.

    My Halls chair originally came with a horribly sagging nylon seat sling. I had them make me an aluminum pan to replace it; it resulted in me sitting up taller, which I liked. I don't recall having to adjust to the difference in height because I immediately liked the extra support/lift it gave me. I prefer sitting up taller. I've not had a seat sling since.

    Unlike the carbon fiber seat pan strips on Toto's ergonomic frame, my carbon fiber pans are single sheets, though I had "vents" added to the one on my ZR2 mostly for extra weight reduction. Because his are strips, Toto's seating system probably has more give to it than mine. Not having tried a similar set up I couldn't tell you how great a difference there is between the two.
    Last edited by stephen212; 10-21-2012 at 07:12 PM.

  8. #18
    I'm sure those "vents" make a ton of difference!

    Still, they look cool.


  9. #19
    Quote Originally Posted by SCI_OTR View Post
    I'm sure those "vents" make a ton of difference!

    Still, they look cool.
    Not a ton of difference, but at least a few ounces. (Hey, every little bit!)

    I stole the idea from Erick Bryant, commander and chief of Round Betty, who in turn stole it from Toto. We're all one big happy CC family, after all.

    Plus they may give the pan a little give, a little bounce -- maybe. And yeah, it looks cool, too.

  10. #20
    Quote Originally Posted by stephen212 View Post
    Not a ton of difference, but at least a few ounces. (Hey, every little bit!)

    I stole the idea from Erick Bryant, commander and chief of Round Betty, who in turn stole it from Toto. We're all one big happy CC family, after all.

    Plus they may give the pan a little give, a little bounce -- maybe. And yeah, it looks cool, too.
    And then Kuschall copied us...

    http://www.kueschall.ch/en/Active-wh.../3D-video.aspx


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