Sidecar Design Formula - IMPORTANT!

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

  1. gkam

    gkam Been here awhile

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    If we are not interested in using the motorcycle as a two-wheeler, it is preferable for the support points to be welded to the frame or screwed?
  2. Strong Bad

    Strong Bad Former World's Foremost Authority Supporter

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    The quality and design of the connection is more important than if it is a connection that is bolted or welded. In other words the question is too vague to give a good answer as there are numerous ways to make a good bolted connection and a bad welded connection.
  3. DRONE

    DRONE Dog Chauffeur

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    If you want decent advice, start a new thread with the bike model in the title, post pictures of it, then ask for suggestions. An endless supply of experienced hackers here won't steer you wrong.
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  4. claude stanley

    claude stanley Claude

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    Welding to the motorcycle frame is somewhat of a concern IMHO. Frames vary from bike to bike of course. Aluminum frames I personally would not touch for various reasons. Pressed steel frames ? Nope. Tubular frames ? Many have done it in years past but I have seen frame failures related to this. So....my answer would be no.
  5. LBS-USA

    LBS-USA Been here awhile Super Supporter

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    +1 on Claude's sage advice, no welding on frames. In addition to "unintended" effects on materials and structure, I'd be concerned about the welder's ability to insure that all electrical and digital components are protected and isolated, especially those motos with chassis ground.
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  6. Loutre

    Loutre Cosmopolitan Adv Super Moderator

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    thinking more and more about converting my 1150GSA into a side car and think i"ll pull the trigger in spring. Tripteq are just 4 hours from where I live and that's actually the frame that i'd buy. They sell it as a DYI kit.
    [​IMG]
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  7. Strong Bad

    Strong Bad Former World's Foremost Authority Supporter

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    I've been welding on cars and bikes since I was knee high to a tadpole (52 years) and actually it isn't an issue as long as you don't have the electrical stuff between the ground and what you are welding. People use to freak out about not disconnecting batteries too. It's all about the current's pathway, which only exists between the ground and the work. But the whole heat affected zone and it's annealing effect is a much bigger problem.

    There are people who won't weld gas tanks either.
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  8. claude stanley

    claude stanley Claude

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    Good point on electricals as there is much to consider there especially with the newer more high tech bikes ,,,caution and knowledge is important.....also the frame material itself as you alluded to. This is critically true with steel or aluminum.
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  9. claude stanley

    claude stanley Claude

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    I think we are all saying about the same thing although in print it may not seem that way or be taken that way by the readers. ..........Welding is iffy at best and not a good idea especially on the later model bikes. The annealing of areas, the type of welder utilized etc etc is a hodgepodge of statements no matter who writes it that may be true in one case and not another as read by the general public. You with the baja type experience and my own experience of nany years in the circle track world could probably tell stories of disaster until the campfire went out. Heck years ago many laughed at those who went with heli arc and the same when wire welders came out. Materials differ and there are unknowns when we get to talking modern cycle frames ,,,, could go on and on on that. In the name of safety it is best to go with bolt on items with over building not being a sin at all.
  10. davebig

    davebig Another Angry Hun !

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    https://www.lincolnelectric.com/en-...heory/Pages/work-lead-connections-detail.aspx

    I'm going to poke a little fun at you two :lol3 The guy I used to help was also an electronic tech and welder repair tech.
    The ground became the work cable along time ago for the reasons Strong Bad pointed out ! If they think it's a ground they try and ground it an I'm sure you guys know how electrons like obstacle courses when they are moving thru your work ! All they want is a way home, keep the work cable as near to the work as possible.
    That's the only welding advice I dare give you two :lol3 Happy Thanksgiving !
  11. Strong Bad

    Strong Bad Former World's Foremost Authority Supporter

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    Excellent comments Claude! Indeed experience goes a long way when considering what you should or shouldn't do when welding all kinds of different stuff.

    I personally do not like the idea of welding a mount for a sidecar without first trying to eliminate all other potential options using fasteners or sharing mounts on the bike. My DMC rig is a good example of using existing mounts on the bike to attach the subframe and other mounts.

    Think of welding a cap on the end of a piece of pipe that's say like 2' long. Place the ground about 6" back up the pipe from your weld. Get someone to attach a volt/amp meter to the other end of the pipe and to the ground while you are doing the weld. And tell me what the voltage or amps you see at the opposite end from the weld. Hint: don't do it between the ground and the weld or you might have to buy a new meter.:lol3:lol3

    Happy Thanksgiving all!
  12. Bobmws

    Bobmws Curmudgeon At Large

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    Years back I worked part-time in a foreign car repair shop in the PA rustbelt. Went in one day and had to pull a gas tank that leaked. The shop owner said he was going to weld the tank! He took the removed tank, flushed it with water and ran a hose from the exhaust of a running car through the tank and proceded to braze a patch on the tank!
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  13. CCjon

    CCjon Gypsy Rider Supporter

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    Not being a welder have to ask, why running the exhaust through the fuel tank from another vehicle helped with the brazing process?
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  14. robtg

    robtg Long timer

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    ^^^ It displaces oxygen and keeps the gas fumes from exploding and ruining your day.
    It doesn't help with brazing but you live longer.
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  15. Strong Bad

    Strong Bad Former World's Foremost Authority Supporter

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    Egg Zackery!

    When talking combustion (rapid oxidation or very rapid oxidation as in an explosion) it only occurs with in a fairly narrow range of mixtures of fuel and oxygen. The ends of ranges are expressed as the Upper Explosive Limit (UEL) and Lower Explosive Limit (LEL). At mixtures below the LEL, there is too much O2 and too little fuel (lean). At mixtures above the UEL there is too much fuel and to little O2 (rich). Have the mixture fall between the LEL and the UEL and you get what Elon Musk calls at SpazX a RUD (Rapid Unscheduled Disassembly).

    I've displaced the oxygen forcing the contents of the fuel tank to fall below the LEL before welding on them with CO, CO2, and various different weld shielding gases.
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  16. claude stanley

    claude stanley Claude

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    Did you all run methenol in the Baja outfits ?
  17. Strong Bad

    Strong Bad Former World's Foremost Authority Supporter

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    No, not practicable.

    In the big 800hp "Trophy Tucks" if we could step up from 2.5 to 3 mpg we were really happy!! The race fuel of choice is VP C16 (116 octane) which is just over $1,000 a barrel. The fuel capacity in the race truck is in the 80 to 100 gallon range. So the fuel cost to run a Baja 1,000 is not for the faint of heart. With alcohol you would have to take another 25 -30% off of your mileage.
  18. claude stanley

    claude stanley Claude

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    Didnt figure you ran methenol but was curious....yes you would certainly spend more overall. Point was that welding on a methenol used tank is not as 'scary' as gas......unless someone tipped the nitro jug into it.
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  19. steam powered

    steam powered just a regular punk

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    Not so much the cost of the additional fuel as the increase in weight to carry the additional 30 gallons of fuel required to maintain the same range I suspect.
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  20. Strong Bad

    Strong Bad Former World's Foremost Authority Supporter

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    If you are worried about the cost, you are racing in the wrong class. :lol3 They have a saying with those who race in the "Country Cluber" Trophy Truck Class: "How do you make a million dollars racing Trophy Trucks? Start with two million!" :lol3

    The extra 180lbs for 30 additional gallons and the volume of where to put it is an issue. Also, I'd have to check the rules, but it may not be legal. Also in a pinch you wouldn't be able to be get fuel from another source out on the race course if needed.

    To really digress with alcohol in containers and flames:

    Back in the late 60's as a bunch of pot smoking stoned teens, we used to make what we called "Fire Bottles" using the old school 5 gallon glass water bottles. Here are examples of different fuels and containers and flame progression:

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