elliptical rear wheeel

edited July 2017 in General Discussions
oqw4q2b3roab.jpg

That's my new high speed elliptical rear wheel or a photo illusion.

Comments

  • Water on the lens causing distortion :)
  • Photo illusion.

    This is a fairly common effect with camera lenses. There is distortion on the edges of the photo, generally caused by a curvature of the lens. This is fairly typical of all lenses, but pretty common in low cost ones. Such as those in cell phones.

    Expect to pay several thousands of $ for lenses without some level of distortion such as this. There are professional grade lenses for those few of us hardcore photographers out there. And there is also software designed to remove the distortions, generally run on a pc and matching a lens to a camera body against tested knowns . (DXO Optics Pro comes to mind.) Big bucks in either case.

    This is be barrel distortion. This pushes the image out in the edges of the frame, leaving the middle in fairly good condition. You can recreate it by placing a ruler or 2x4 on the edges of test photo and watch it turn into a pretzel. (Brick build photos are common places to see this, too.)

    Another common distortion is called Pincushion, where it pushes the middle of the edges in towards the center of the frame. (The reverse of what you have here.) Truly bad lenses can have both, depending on where in the frame you examine it.
  • But doesn't anyone want to know how it rides ? :)
  • edited July 2017
    It probably rides about the same as the elliptical rear wheel on your van. :-) In fact, if one looks very carefully, the front wheel of your van has a slight "ellipticalness" about it also.
  • And the Subaru has a sorta banana shape
  • at least one inquiring mind, if you would be so kind sir, interested in how such a fine-looking machine rides. more so since the usual review of the zoomer doesnt sound adequate and same source has interesting comment about new spindles on the review of the sportster.

    http://www.bentrideronline.com/?p=1985

    personal opinion any tadpole with decent brakes will lift the rear end under serious braking. i gather hydraulics can make life even more interesting.

    main question: how do you find the handling doing fast downhills when going straight? review comments on the sportster got me wondering.

    was your original trike a 20 incher? if you upgraded to 26 inch rear did it change the handling much?

    do wish i could get out of a trike that low, looks a pleasure to pedal. kinda like the look of your wheel, actually. tempted to loosen and tighten a few spokes on old faithful to match that style. i figure if oval chainrings have any benefit, oval wheels ought to have even more.

  • JamesR wrote: »
    at least one inquiring mind, if you would be so kind sir, interested in how such a fine-looking machine rides. more so since the usual review of the zoomer doesnt sound adequate and same source has interesting comment about new spindles on the review of the sportster.

    http://www.bentrideronline.com/?p=1985

    personal opinion any tadpole with decent brakes will lift the rear end under serious braking. i gather hydraulics can make life even more interesting.

    main question: how do you find the handling doing fast downhills when going straight? review comments on the sportster got me wondering.

    was your original trike a 20 incher? if you upgraded to 26 inch rear did it change the handling much?

    do wish i could get out of a trike that low, looks a pleasure to pedal. kinda like the look of your wheel, actually. tempted to loosen and tighten a few spokes on old faithful to match that style. i figure if oval chainrings have any benefit, oval wheels ought to have even more.

    JamesR,
    My Zoomer is the SL model which is a further refinement of the 26" model. It has a 27 gear range and 1.1" Durano tires at 85-90psi. Actually weighs in at 30lbs.
    The handling is extremely quick and took me a season to get used to it and appreciate it. The brakes are very effective but I've never had the rear lift except when slamming them on full lock at slow speeds when I was figuring the ride out. Downhills are manageable up to 35mph, that's where I start to feather the brakes, I do not want to run into any object feet first so that's my speed limit. On sorta level ground it's a dream and I can get into the low 20mph range for sprints and maintain 17-18 comfortably.. The frame flexes to absorb some road shock even with the thin high inflation tire.
    The seat is VERY comfortable and the overall fit is good for me being 6'1". The boom could still be extended some if needed. The seat is 8" off the ground so getting out can be a issue for some, after a hard ride I rest for a couple minutes before trying ! Getting in is easy. Main complaint is the handle bars are a tad close, wish they could be moved forward a couple inches.
    Hills are my fail and we have plenty of them where we ride. There is a Class5 ( method for rating hills) hill that occasionally forces me to dismount and grab the rear wheel and walk the remainder ! Great trike but obviously not in the manufacturers marketing plan. Sportster is similar but has a much higher seat and is wider. The Zoomer has a 27" from wheel track, very narrow.
  • edited July 2017
    Your Zoomer looks like a fantastic ride. While we are very pleased with our Sportsters, I have found myself wishing that the Zoomer had still been an available model when we made our purchases last summer.
  • Reading the review that JamesR linked raises a question for me. The review references "a bit of chain drag and power loss from the dual idler system." With no experience with chain tubes versus the idlers on our Sportsters, is this reviewer suggesting there is less drag with chain tubes than idlers? That seems counter intuitive to me. My minds eye would think idlers offer less drag than tubes. Am I wrong on this?
  • Reading the review that JamesR linked raises a question for me. The review references "a bit of chain drag and power loss from the dual idler system." With no experience with chain tubes versus the idlers on our Sportsters, is this reviewer suggesting there is less drag with chain tubes than idlers? That seems counter intuitive to me. My minds eye would think idlers offer less drag than tubes. Am I wrong on this?

    Agree
  • There is chain drag in the tubes. Never had an idler.

    ¬ ITL
  • chaintube thing has gotten to the point of ridiculous.

    zoomer is a beautiful classic trike, can only think of replacing its idlers with chaintubes as an example of uglification. suspect idler drag is more theory than real, something that belongs with the folks who wont ride with innertube valve caps to save precious grams.
  • JamesR wrote: »
    chaintube thing has gotten to the point of ridiculous.

    zoomer is a beautiful classic trike, can only think of replacing its idlers with chaintubes as an example of uglification. suspect idler drag is more theory than real, something that belongs with the folks who wont ride with innertube valve caps to save precious grams.

    uglification is correct, cannot imagine idlers creating more drag then a chain tube.
Sign In or Register to comment.