Sidecar Design Formula - IMPORTANT!

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

  1. Ockrocket

    Ockrocket Long timer

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    Well, I haven't read the whole thread, but I'm glad you did.

    I'm about to embark on getting my outfit to stop trying to do constant right turns [Australia, runs me head on in to oncoming traffic if I let go my "Tarzan's grip" of the bars]

    So I thank you for posting a thread that will give me a starting point to work from. :thumb

    I will read from end to end [excluding the derogatory and non relevant comments] to learn what I can as I work it all out.
  2. Bobmws

    Bobmws Curmudgeon At Large

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    Some good downloads on this page on both setup & operation.
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  3. Ockrocket

    Ockrocket Long timer

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    Thank you, I will have a hunt through there as well.
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  4. Ockrocket

    Ockrocket Long timer

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    This is all going to give me a headache... why do you lot all insist on riding/driving on the wrong side of the road? :hide

    So given that the bike is on the right hand side of the sidecar.. and the whole outfit pulls to the right quite strongly..

    I presume I should substitute the "pulls right" problem of my bike for the "pulls left" solution in the diagram below?
    Or is it more complicated than simply reversing all the Problem-Solution steps?

    Having not owned the bike for long [or more to the point, having my licence suspended on medical grounds and only recently having it reinstated, I've not yet had a chance to ride the outfit much], and having recently put it in to a tree, I've not checked the alignment of anything yet.

    The bike didn't pull as badly as it does now, so I'm guessing I've dislodged something that isn't obviously visible.
    There is nothing visibly broken or bent on the frame of the bike or the chair chassis.

    Looking at the outfit from front on, the bike does look to be leaning out a long way, and it has done since I first bought it.

    I need to measure for numbers compared to what a standard toe in/lean angle should be and take the adjustments back to there, and then see what it handles like.

    C and B measurements should be taken in line with the front and back extremities of the bike tyres/wheels?
    Or taken as close as possible to where the tyres contact the road? [obviously the two straight edges I will be using to check won't be parallel, the further apart the measurement are taken the greater the difference will be]

    Now I need another beer I think. :drink

  5. Ockrocket

    Ockrocket Long timer

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    Well all I've had the chance to measure is the lean out when I got home tonight [needed to pick up a builder's square and a couple of long lengths of angle iron before I could measure anything].

    My lean out angle is 5/8th of an inch, or 16 mm... so I guess that is a bit too much just for starters.

    If I get time tomorrow I will check the toe in/out between the chair and the bike.
  6. ANKOF

    ANKOF Been here awhile

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    question.
    how does the strains on the attachment points on the bike and sidecar work? when it comes to build, lets say a complex roof, I have no problem visualizing how it works. how the forces affekt each other and how to distribute them to areas that can take the load or equalize them over the construction.

    on a sidecar I dont get it. I want to understand the physics.

    on a sidecar cross I see the upper forward attachment as cruical when going to the "other side" of the sidecar. on a ordinary rig I can only see the attachments as weak, still it seems to work. but how?
    what forces are we talking about and how do they work?

    one more thing, there is different aproaches to what to use for attachments. the cheapest graded way I can find is the top strut from the back of a agricultural tractor. its cheaper than the material to build my own struts from scratch.
    What do we think about that? the threaded rod on the one below is 3/4"
    [​IMG]
  7. ANKOF

    ANKOF Been here awhile

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    ball joints can move yes, but if you dont triangulate the struts properly you will get all forces on the attachment point itself and stress them??

    leverage and working mass. yes, but how does this affect the construction? if done wrong there must be a lott of stress and fattigue on the joints

    there is allso the possibility to weld the "balls"
  8. willys

    willys Long timer

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    I also am interested in the answers to using this type of joint, above...? Is it made to the standards of the hyme joints we usually see being used, i doubt it personally....seeing it's intended use, farm equipment..? BUT is it still strong enough for our needs? Just curious..thanks
  9. brstar

    brstar Been here awhile

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    Looks like a top link from a category 1, 3 point linkage for a small tractor. If you understand the jargon.
    I was surprised the other day when I bought just the eye part with a threaded shank.
    I was expecting plenty of sloppy play that would have made it a bit annoying or even useless for sidecar use but the piece I bought seemed to have a snug fit and smooth operation.
    Just the way I like it :lol2.
    The threaded part most likely would need left and right hand threaded lock nuts along with locktight to keep things in adjustment and to stop movement.
    They seemed quite cheap as well.
  10. Clancy

    Clancy Long timer

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    I generally don't answer the for and against type of discussion in here these days, but I might just add a bit of "proof is in the pudding" comment by way of a couple of pics. The set up below has done, the Tanami, Gibb River Road and just about everything in between. All credit To Phyliss and his work, it hasn't broken, hasn't moved, and once it was set up, hasn't needed adjustment.
    Only good quality heims were used, with LH and RH threads. It's always loaded with enough gear to sink a couple of ships, and nothing has ever broken.

    [​IMG]

    [​IMG]


    [​IMG]
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  11. brstar

    brstar Been here awhile

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    Meh! Gibb river road... My sister did that run 25 yrs ago in her school bus...... True!
    Family holiday so they took out most of the seats and put in mattresses.
    She hammered it as well, every so often the 2 speed diff bounced out of gear from the corrugations.
    Mind you I was hoping for a response as the cat 1 bits while cheap and strong may not cut it.
    On the quality hiem joints and threaded connectors are there any part numbers????
    Sizes??
    Enquiring minds would like to know
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  12. Clancy

    Clancy Long timer

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    Yeah, yeah, heard all about everyone and their Auntie driving up the Tanami in their Anglia. Never met any of them but.:lol3
    No part numbers Bruce and I'll go out and measure 'em in the morning. They're 3/8 I think, but I'll check. At my tender age I can be forgiven for forgetting something we did two years ago:gerg
    Had the same setup on the K1100 and never had a problem. The connecting rods weren't bought. Phil made them and I'm not sure what grade aluminium he used.

    But trust me, the heims weren't cheap. Buy cheap and you're just buying trouble.

    They're race car stuff that I brought in from the US from where we bought all our stuff when we were racing.

    [​IMG]

    [​IMG]
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  13. bk brkr baker

    bk brkr baker Long timer

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    Big difference in weight between what Phyliss made and 7 top links from the tractor store. Steel vs. aluminum. And the custom lengths to get the perfect fit , not easy with off the rack parts.
    But strength ? Pretty sure if a top link can pick up half a ton or so , seven in combination won't fail with a 1400 lb. all up rig.
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  14. brstar

    brstar Been here awhile

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    I suppose its why they only have 3 in their point linkage.
    Yeah I know the 2 don't equate.
    But I do relate to simple...........
  15. ANKOF

    ANKOF Been here awhile

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    the top link on my picture is cat 0. the threaded part is 3/4" unc, costs about 15$ each. its good quality and takes a lot of abuse on a small tractor. The cat 1 is 1 1/8". they must be complemented with lock nuts to stop all movemet in the threads. I can adjust the length on the pipe by shortening and welding if necessary.
    Clancys arrangement above seems solid in my eyes. if you depend on a solution where the friction in the attachment points is the only thing that keeps the arrangement to move, that will in my eyes put all the forces on the joint itself and make it a weak point as time will pass??

    my bike has worked fine for about 30000km but on a longer trip this summer everything started to move. tried to shim and pull harder and it made things better for a while but didnt solve the problem in a longer run. my conclusion is that the material in the heim joints is weakend/damaged. (Ive allso been using velorex parts on the bike frame which is a bad idea to start with I think.)
  16. bk brkr baker

    bk brkr baker Long timer

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    [​IMG]

    [​IMG]

    A slightly different take , with short fabricated links triangulating each other. No way for the joints to slip.
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  17. willys

    willys Long timer

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    I was at the tractor store near me a couple of days ago and looked at those bars for the 3 point hitch...the eyes are stamped and do have play that will relate into a big difference at the end of the unit you are trying to control over it's full length...imho...I also was thinking about using them but after seeing the quality and their wieght, there is no way i'll be using them, sorry to say!.....I'll spring for the far lighter hiem joints and threaded rod and do it once right..... I know not what you wanted to hear...sorry.
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  18. claude

    claude Sidecar Jockey

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    We do not use heim ends for various reasons but if you are going that way, as mentioned, use good ones. Make sure triangulation is good and adding an additional link, as Phyllis did, is a VERY good idea. If you contact 'Stock Car Products' they can make the links for you in either aluminum or steel, swaged ends or not. If you wish to make your own you could use 6061T6 Aluminum ... 1" x .250 wall tubing. It will tap out to 5/8" so is pretty simple with little hassle to work with. This was the mainstay for sprint car radius rods for years and holds up very well.
    [​IMG]
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  19. ANKOF

    ANKOF Been here awhile

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    the one Ive got on the tractor is quite solid with no play at the eye. I just want to discuss pros and cons with these. as I said above I find the sidecar specific stuff over priced. the alu stuff you mention is cool claude but normaly I would not consider heims ends to the price they normaly at with the cons that come with their moving ability. Where can I find "fork" ends in good quality for resonable price? there must be other applikations for these but Im having trouble finding the right sizes. that alu tube above with fork ends would look cool:-)
  20. FR700

    FR700 Heckler ™©®

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    Your imagination.
    What you are looking for is a clevis.

    I'll often have people tell me they can't afford decent fittings, yet they'll have a fridge full of beer :lol3




    .
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