Sidecar Design Formula - IMPORTANT!

Discussion in 'Hacks' started by Get Back, May 25, 2009.

  1. Richard-NL

    Richard-NL Sidecar Fan

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    You’re so right. I was writing an answer, with a lot of pics like the ones below (shortened it now to three) expressing that the idea (basic info) in the end, isn’t very different. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
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    You just write better. :wink: <o:p></o:p>
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    Richard-NL :bmwrider <o:p></o:p>
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    #61
  2. RedMenace

    RedMenace Adventure Sidecar

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    Sure, and if I did modify the front end to reduce trail, steering effort could be reduced to compensate for or mask the effects of the of sc wheel lead scrubbing the tires, but unless I significantly change the dimensions that effect would still be present, no?

    I intend to modify the front end of the Suzi, but minor crisis' keep popping up to prevent me from turning my attention there...

    #62
  3. RedMenace

    RedMenace Adventure Sidecar

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    The conversation here has turned reasonable and somewhat useful? I wonder if this thread should be returned to join the original thread?:freaky
    #63
  4. Nemo DeNovo

    Nemo DeNovo Banned

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    +1 :thumb
    #64
  5. koifarm

    koifarm Twas ever thus!

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    I have to agree with you Red, it has been most informative from all posters and is definitely a wonderful addition to the information base. Glad to see everyone has settled down and is coming forth with useful information.
    Can the mods add this to the original thread?:clap:D
    #65
  6. McCardigan

    McCardigan happy Budda

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    #66
  7. claude

    claude Sidecar Jockey

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    Asimple test on any rig to see what scrubbing may take place is to turn the bars with the rig at rest on solid ground or pavement. When doing this look at see how much the sidecar wheel moves fore and aft. Then do the same deal on a rig with reduced trail and you will see much less movement.
    Less lead, reduced trail and less track width will make the sidecar wheel scrub less when the bars are turns. The key is to balance out all the factors to arrive at a good compromise for handling and safety.
    Vernon from reading your posts for a long time it seems you like light sidecars. That is fine of course but many also prefer heavier sidecars. I kinda prefer havier for the most part but like light sidecars also. The difference in riding technique is a reality as is the handling. The approach to making a rig work will vary some depending upon the rig but the basics and the effects of them will still be the same for the most part.
    #67
  8. Richard-NL

    Richard-NL Sidecar Fan

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    A lot of lead and then.......?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
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    The French Sidecar Factory “Side-Bike” uses <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:eek:ffice:smarttags" /><st1:metricconverter ProductID="18 inch">18 inch</st1:metricconverter> (<st1:metricconverter ProductID="45 cm">45 cm</st1:metricconverter>) lead on their outfits but at the same time they have sidecarwheelsteering and central hub-steering in the front. The Zeus has <st1:metricconverter ProductID="14 inch">14 inch</st1:metricconverter> (<st1:metricconverter ProductID="37 cm">37 cm</st1:metricconverter>), a lot less, but this one doesn’t only have twowheeldrive, but also rear-wheel-steering on this outfit with a <st1:metricconverter ProductID="79 inch">79 inch</st1:metricconverter> (<st1:metricconverter ProductID="200 cm">200 cm</st1:metricconverter>) wheel base. <o:p></o:p>
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    In 2001 EML from the <st1:country-region><st1:place>Netherlands</st1:place></st1:country-region> started a new project with their GT Twin for heavy bikes like the Honda GL1500 and 1800 and the BMW K1200LT. I think the following pics say enough, about what their ideas were at that time towards lead and heavy large outfits. <o:p></o:p>
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    Drawings of the frame:<o:p></o:p>
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    Pics of the frame: <o:p></o:p>
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    It worked. <o:p></o:p>
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    I’d rather not have the discussion whether this still is a sidecar-outfit. Thank you very much. Like the Zeus, it rides like one, but indeed it’s a little “different” and also not my cup of tea. <o:p></o:p>
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    Richard-NL :bmwrider

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    #68
  9. RedMenace

    RedMenace Adventure Sidecar

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    You are correct, I do prefer light, simple sidecars. My Suzi rig is relatively heavy, however. It is extremely stable and, once I reduce the steering effort a bit, should be an excellent street rig. As it is, with stock telo front end, stubby handlebars and nearly 14" of wheel lead, it handles well but with enough steering effort to be quite tiring and difficult to push through a tight corner at speed.

    Do I understand you to say that reducing trail alone will reduce tire scrub? Why would that be, I wonder? I understand how it would reduce the feeling at the handlebars, but the tires would still be fighting each other trying to turn a different arc through the corner, resulting in scrub or crabbing.
    #69
  10. phyllis

    phyllis just another dummy

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    Looking back at some old Motorcycle Sport mags(the English ones) there is an article about the double wheeled sidecar Squire made and tested but never took to the marketplace. The small (10"?) wheels were mounted on each end of a short beam that was itself pivoted on a sprung trailing arm. The trailing edge of the forward wheel almost touched the leading edge of the rear wheel. The idea being to reduce the "wheel rate" (spring strength) of each individual wheel because they could ride the bumps independently. Soft over the bumps, but firm when loaded in a corner, less dive. Like the main landing gear bogey on Boeing 747s, (trucks too? sorry,Lorries?) Probably too many wheels to remain classified as an outfit. Sorry no scanner,:cry, so no picture. Wonder how they measured the lead on that one??:lol3
    #70
  11. claude

    claude Sidecar Jockey

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    Richard NL WROTE:
    >>>The French Sidecar Factory “Side-Bike” uses 18 inch (45 cm) lead on their outfits but at the same time they have sidecarwheelsteering and central hub-steering in the front. The Zeus has 14 inch (37 cm), a lot less, but this one doesn’t only have twowheeldrive, but also rear-wheel-steering on this outfit with a 79 inch (200 cm) wheel base.<<<

    Yes, a steering sidecar wheel such as on the Comanchee and others can allow a rig to gain the benefits of running more wheel lead without the drawbacks of doing so with a conventional design. But....things can become complex pretty quickly. There are also other drawbacks.
    Still comes down to where one wants to meet the compromises confronted with and how important one feels it is to narrow the margins. Or in some cases maybe marketing plays a role in the mix too.
    #71
  12. claude

    claude Sidecar Jockey

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    And then there was Floyd 'POP' Dreyer who built a caster wheel for the sidecar that just kinda followed along. Bugger to roll backwqards though:wink:
    #72
  13. phyllis

    phyllis just another dummy

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    Did Hack'd magazine ever publish Mr Ewing's views on sidecar wheel lead?
    I thought he was on the ball on most of the topics I have read of his.
    I have copies of his "Tires tell the tale" and "Leanout". He must have had something to say about Lead.
    #73
  14. claude

    claude Sidecar Jockey

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    I just emailed Gary and Chris to ask them that. We were down at their place over memorial day and they are doing fine. Chris does have alot of back issues of Hack'd. They have talked for a long time of maybe putting J'R's writings into one book. Sure woudl be a good read as he did get into a lot of things when he was still with us. Quite a guy.
    #74
  15. claude

    claude Sidecar Jockey

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    A little more reseach on the net and I found this:

    These were in Hack'd Magazine:
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    Volume 11 # 2 Fall 1994
    Wheel Lead Formula; Peter Smith shares his engineering technology in verse and drawings. (This is the one that was posted here)
    ..........................................................

    Volume 13 # 2 Fall 1996
    J. R.. Ewing explains sidecar wheel lead

    .........................................................
    #75
  16. phyllis

    phyllis just another dummy

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    Thank you for that reference Claude. How can I begin to even start to say how much I agree with EVERYTHING Mr. Ewing says in those few pages.
    I feel such a fool. I read it just now, and am feeling as though he is laughing at me for being so Big Headed. The side car world lost a giant when he left us, Jim Dodson too. I've got most of the issues of Hack'd Magazine, how could I have missed that ABSOLUTE GEM.

    Mr Moderator...take down all my ravings..... and put up Mr. Ewing's thoughts!
    The bit about reasoned protest "with courtesy" , will be taken to heart my me, I'm in the presence of a better man! Sadly on longer with us in the flesh.
    #76
  17. Nemosengineer

    Nemosengineer Hair Ball

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    Claude, I don't know why I like this idea so much, elegant in its simplicity, but as we all know, the Devil is in the details. As I "roll" the caster wheel around in my head, I can visualize really interesting weight transfer issues when turning left at speed, the pivot for caster wheel would mean that the rig would have a variable track, working in your favor as the track would be narrower turning right and wider turning left, if an inclined pivot on the vertical axis of the caster wheel (left and right rotation) was used, the wheel would have less of a tendency to tuck under when side loaded as in a left turn.:huh I also have visions of the one spastic caster wheel on the front of a shopping cart...:eek1
    Do you have any more information as to how well (or not...) this idea worked as I am fascinated by this idea.:D

    Thanks: Mike:freaky
    #77
  18. RedMenace

    RedMenace Adventure Sidecar

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    I am saving the gist of Phyllis' critique of the "15% solution" because it merits a closer look and I don't want to lose it if the post is nuked. I gots some thinking to do, yet.:wink:

    #78
  19. Andy-Gadget

    Andy-Gadget Any bike can go anywere

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    Talk about thinking outside the square, what a great idea.

    I too have been doing the "rolling it around in my head" thought experiment as well, and as you say, going backwards has issues.
    But with travel limits on the amount of caster the chair wheel is capable of moving through, so it can turn both directions with no scrubing, wow.

    You could even use a spring arrangement to provide the conventional toe in vector towards the tug, hmmm, to be given much more thought.

    That's what I love about this whole Hacks forum, there are as many ways of solving a problem as there are people to solve it.
    It is the experiment that will prove or disprove the validity of any new approach.
    #79
  20. claude

    claude Sidecar Jockey

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    #80