Sidecar Design Formula - IMPORTANT!

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

  1. Old Mule

    Old Mule Long timer

    Joined:
    Mar 24, 2013
    Oddometer:
    1,189
    Location:
    Overland Missouri, home of 1950s sidecar tech.
    Checking alignment as I was touching up frame paint, I measured my machine. Looking at the modern ones with car tires and body work, I realized how small my sidecar combination is.

    Track 43 1/2"
    WB 56 1/2"
    Lead 10 1/2"
    Width over all 59"

    Also saw this week a 1962 BMW parked next to one of the new six cylinder models. The new one is colossal! How one would change a tire or even pick one up, I don't know. Is it better or just bigger?
    Met a guy with a KTM 1000 off-road sidecar. the top of the tank was high as my chest.
    I once read an article in a 1922 issue of The Motor Cycle wherein the writer said that when a motorcycle weighed more than its rider, all finesse of control was lost and the pleasure of riding disappeared.

    Just idle musing, or, as in old R&T magazines, miscellaneous ramblings.
    pops, rantingsmith, brstar and 2 others like this.
  2. rantingsmith

    rantingsmith Quadrilingual blacksmith seat of pants engineer

    Joined:
    Feb 27, 2017
    Oddometer:
    121
    Location:
    UK for now but not from here
    The same is true of many cars, or even US cars vs the rest of the world, was talking to someone yesterday who's friend imported a classic Challenger but has to reverse it out of the drive to change half shaft as it is too wide to do on the drive between the houses.. I am not sure there is anything to be gained from supermassive bikes the whole thing just ends up too heavy and a pain to manoeuvre at anything but cruising speeds.. I have stripped about 15-20kg off my XV750SE and am working towards about 40kg for my TR1. The sidecar is a different story, a balance between light for performance and heavy for handling. I'll be trying to keep the wheelbase and track width short and narrow for low speed manoeuvreability but the chair will be weightier to help with cornering when in solo use.. I also have to consider my ride height carefully as low is better for handling but I do live up a farm track complete with grass growing up the middle so I want to avoid grounding out with a passenger.. anyone ever hear of an air ride fitted to a sidecar..?

    Cheers,

    Rant
    Old Mule likes this.
  3. Hvymax

    Hvymax Been here awhile

    Joined:
    Sep 22, 2016
    Oddometer:
    236
    I have my concept coming together. A linkable adventure leaner with luggage platform that can take a chair.
    RetiredandRiding likes this.
  4. brstar

    brstar Been here awhile

    Joined:
    Aug 17, 2007
    Oddometer:
    994
    Location:
    Shoalwater Western Australia
    I must admit my leaner is nice to steer on the freeway though I have not put a suitable locking brace for off road use on it.
    I only have one to hold it upright while parking.
    Maybe I should?
    It has a platform with a fold down seat from an old school bus that no one has so far been silly enough to use.
    Probably need some body work surrounds.
    Stil it is all a compomise.
    But some things need to be experienced.
    And that without a negative connotaion.
  5. Hvymax

    Hvymax Been here awhile

    Joined:
    Sep 22, 2016
    Oddometer:
    236
    An air adjustable swingarm with long slots for adjustment. I can use the upper skidplate bracket to mount the front pivot and the centerstand bracket for the lower rear bracket. This will be on my KLR 650.
  6. cycleman2

    cycleman2 Been here awhile

    Joined:
    Jan 18, 2010
    Oddometer:
    925
    Location:
    Alberta, Canada
    You can put air shocks on the car if you want, but you'll have to check with the lengths available, most where put on big road going bikes and they didn't have a lot of suspension travel. With air the more you add the higher they ride, but the harder they ride. Not really a good thing on a sidecar. Air shocks don't work anything like an electric lean adjust. They are a nice to have thing and a whole other topic.
  7. moffit virtue

    moffit virtue Japa

    Joined:
    Feb 20, 2011
    Oddometer:
    50
    Location:
    Northern tablelands N.S.W.Australia
    air springs are the go 80psi- holds it square and smooth,corrigated dirt not a drama.
  8. Strong Bad

    Strong Bad Former World's Foremost Authority

    Joined:
    Oct 29, 2007
    Oddometer:
    7,887
    Location:
    Omicron Persei 8
    Air shocks suffer from stiction and if you have a seal failure they collapse, not something I want to have happen when I'm out in the bush.
    claude likes this.
  9. moffit virtue

    moffit virtue Japa

    Joined:
    Feb 20, 2011
    Oddometer:
    50
    Location:
    Northern tablelands N.S.W.Australia
    True,as per usual routine maintainance checks for chaffing and a rub with armouralll.
  10. rantingsmith

    rantingsmith Quadrilingual blacksmith seat of pants engineer

    Joined:
    Feb 27, 2017
    Oddometer:
    121
    Location:
    UK for now but not from here
    Well I have a short farm track section, maybe 50 yds from the road to the house and don't really want to ground the hack every time I go out or come back, as for the rest of the intended use it will be a road only hack so low is better..

    Only reason I was thinking air shocks maybe was I came across HD Bagger kits on eBay that seemed cheap and might allow for enough lift to get to and from the road..?

    Also some years back I owned a Citroen BX with hydraulic self levelling suspension which was about the comfiest ride ever and cornered pretty well too, now something like that on a sidecar seems appealing...!?


    Nothing worth doing is ever easy.

    1983 XV750SE CAFE/BRAT - 1981 TR1.1NCENT PROJECT - 1982 XV750/920 upgrade SIDECAR PROJECT w. WATSONIAN MONACO CHAIR
    brstar likes this.
  11. Bobmws

    Bobmws Curmudgeon At Large

    Joined:
    Jun 6, 2005
    Oddometer:
    2,618
    Location:
    Same trailer, different park, FL
    Shovel & rake..........problem solved! :-)
    brstar and rantingsmith like this.
  12. rantingsmith

    rantingsmith Quadrilingual blacksmith seat of pants engineer

    Joined:
    Feb 27, 2017
    Oddometer:
    121
    Location:
    UK for now but not from here
    It is however not my track and not sure shovel is going to be sufficient unless it comes on the end of a tractor/digger.. also putting an air ride or self levelling suspension on your hack is cooler than spending the weekend with a shovel and pick axe..
    Bobmws likes this.
  13. Soupy1957

    Soupy1957 Old but not out

    Joined:
    Nov 5, 2017
    Oddometer:
    41
    Location:
    Connecticut, USA
    This is great stuff!! Don’t you suppose that the Dealer, who has experience doing the setup of a sidecar to a motorcycle, knows and does these connections and adjustments, typically?

    I’m going to suppose that these instructions are most valuable, particularly for DIY’ers, yes?
    Old Mule likes this.
  14. DRONE

    DRONE Dog Chauffeur

    Joined:
    Oct 1, 2007
    Oddometer:
    6,487
    Location:
    Chambers Bay, WA
    You just quoted a post from 2009. Here's your necroposting emoji award -- :grim .
  15. cycleman2

    cycleman2 Been here awhile

    Joined:
    Jan 18, 2010
    Oddometer:
    925
    Location:
    Alberta, Canada
    If you have an on board compressor you can certainly play with the air pressure to raise and lower the shock, but it will affect your lean and subsequently your handling. So if you are going that route I would suggest you set the bike up for the way your ride it once you are off the lane. Then just add the air to get the clearance you need and once you get to the highway, lower it back to where you want it. This could work for small adjustments due to road camber as well. But in the end, the more air the stiffer the car will ride.
    rantingsmith likes this.
  16. claude

    claude Sidecar Jockey

    Joined:
    Mar 17, 2002
    Oddometer:
    5,410
    Location:
    Middleburg, Pa. (Snyder County)
    I think if I was going to run an air shock on the sidecar I would make up a solid (could be adjustable) strut to take it's place in case of an issue when out on the road. It would not take up much room and may be better to have it and not need it than to need it and not have it.
    Old Mule, davebig and rantingsmith like this.
  17. rantingsmith

    rantingsmith Quadrilingual blacksmith seat of pants engineer

    Joined:
    Feb 27, 2017
    Oddometer:
    121
    Location:
    UK for now but not from here
    @cycleman2 and Claude:

    I would have the on road setup as the default with compressor off then run the compressor/airshocks up for getting up the track.

    As for the self levelling part, well the thing that gave me the idea was an old Citroen I used to have. The blacksmith I was apprenticed to was a Citroen enthusiast however and I remember him forever working on mates and club cars repairing the hydrolastic suspension.. so maybe not such a great idea for reliability..

    Ideally what I want to work out is some way of getting an extra 2-3" of ground clearance at the touch of a button or twist of a valve to be able to have the stability my road setup uncompromised by the need to traverse 50yds of bumpy uneven track on the way out and in.. I mean it could be as easy as a reservoir and a couple of airbags.

    Thanks for the input guys. Default setup will deffo be on road and having a failsafe seems a must!

    Cheers,

    Rant.


    Nothing worth doing is ever easy.

    1983 XV750SE CAFE/BRAT - 1981 TR1.1NCENT PROJECT - 1982 XV750/920 upgrade SIDECAR PROJECT w. WATSONIAN MONACO CHAIR
  18. Prmurat

    Prmurat Long timer

    Joined:
    Oct 28, 2011
    Oddometer:
    1,928
    Location:
    Scottsdale, AZ
    Funny you mention Citroën: this is one my dream to have this suspension on a hack! Would be the ultimate comfort, handling and height adjustment possibility. When living in France my father had only Citroën all his life(ID, DS & SM), I had his last DS for more than 10 years and we had only very few problems over all these years. Me thinks it had to do with competent mechanics, right type of oil (red or green and not “anything will do” (only water could be use in extreme emergency!)) and some kind of “respect” for a more complicate véhicule than one fixable with a monkey wrench! If I remember well there was a 750 Kawasaki H2 built here in the 70’ with a Citroën suspension: handling was great but the bike looked complicated!!


    Sent from my iPhone using Tapatalk
    Old Mule likes this.
  19. davebig

    davebig Another Angry Hun !

    Joined:
    Jan 19, 2004
    Oddometer:
    7,960
    Location:
    Minnesota
    Oh boy Philippe and I on the same page it would be cool and handle very well if at least the tug and sidecar wheels could be linked, and adjusted on the fly.
    I live where there are few Citroen's but going to Bastille Days in Milwaukee always turned up a few.
    There was one of these in MN allong time ago !
    [​IMG]
  20. cycleman2

    cycleman2 Been here awhile

    Joined:
    Jan 18, 2010
    Oddometer:
    925
    Location:
    Alberta, Canada
    I guess you could just ride with the wheels on the higher spots, that is what we do up here with dirt roads etc that have a higher uncut grass ( with god knows what hidden in the grass - good for taking out oil pans ). I've had a few goldwings with air shocks on the rear and you don't have a lot of travel, likely about 3 1/2 " from no air to max air. With the inherent problems with air shocks you'd be better off with some kind of adjustable lean setup that you see on some sidecars.

    Or just grade the lane, might be easier in the long run.