homebrew hack questions.

Discussion in 'Hacks' started by villageidiot, Feb 6, 2013.

  1. villageidiot

    villageidiot Long timer

    Joined:
    Apr 29, 2010
    Oddometer:
    2,441
    Location:
    Orange County, CA
    i want to build a hack for my Bonneville. ive got most of it worked out in my head and on some scratch pads etc.

    im getting down to the material selection process/parts selection process before i get underway cutting and welding and wasting time and materials (its never a waste if youre having fun, but it does cost to do things twice)

    the things i cant get around in my head are........

    first, should the hack wheel match the front or back wheel? i know if the rim and tire are the same as the pusher i could effectively "rotate" my tires based on wear when necessary.

    but what is better, big hack tire, or narrower tire like such that the front has, or does it not really matter, just put something on that rolls?

    its going to do mostly street duty, as it IS a triumph bonneville, but it will definitely see some dirt road action. the body i plan on is basically a dimensional copy of the ural cargo box (i love ridingdonkeys bike) but with provisions for a seat to be placed in.

    secondly, should the frame be made of square or round tubing, and what dimension(diameter or box) is adequate? im thinking 1 1/2" .120" wall mild steel, is that overkill? or too light?





    thanks guys
    #1
  2. DRONE

    DRONE Dog Chauffeur

    Joined:
    Oct 1, 2007
    Oddometer:
    4,185
    Location:
    Chambers Bay, WA
    I'm not a hack builder, but I spend alot of time reading threads here, and square tubing is best left to people who really really know what they're doing. Hobby home builders should use round tubing. I believe it's all about strength and flexibility, torsion and stiffness.

    On the tire, just something that rolls will work. If you plan to have a brake on that wheel, an auto tire will have a bigger contact patch, but really any tire will handle braking forces OK. If you need to hit the brakes hard, most of the weight is transferred to the front wheel, so it won't really matter too much if you have a wide or skinny tire on the car because it's not gonna provide a lot of braking power.

    On the other hand, when you are throwing the bike hard around a left curve, a lot of weight gets transferred to the sidecar tire and that's when you want a tire and wheel (and suspension) that won't let you down. It's gotta be able to bite and hold if you don't wanna go sliding onto the shoulder.

    Aesthetically, I like a skinny front-wheel style sidecar wheel only on the lightweight dual sport rigs like a KLR or a DR650. I like an automobile wheel and tire on the high-speed rigs and the heavy rigs. But on a mid-weight rig like the Bonneville, especially if you want it to look good, I'd like to see a rear moto wheel/tire. But since you are putting a cargo box on there, obviously you don't care how it looks, so aesthetics are probably not a factor.

    Ride height is also a factor I'm sure you're already thinking about. The axle on a 19" moto wheel will sit 2" higher off the ground than a 15" rear wheel.

    Just my two cents. But that's what you asked for, right?
    #2
  3. Leaf

    Leaf Been here awhile

    Joined:
    Mar 3, 2012
    Oddometer:
    398
    Location:
    Brandywine, WV
    Disclaimer: I am just a shadetree mechanic, so I may not know what I am talking about.

    I don't think so. I have a 16x2.0 SC wheel and 18x2.5 front and pusher. The SC is on the first tire I ever put on it with about 1/4 tread remaining, while the front and back have gone through many. I like being able to rotate the front and back, but the SC wears so slowly that I don't think it matters.

    I think the only compelling reason to have a bigger SC wheel would be to help get up over big rocks and stuff.

    I think you'll hear a lot of different opinions on square vs round. Round is certainly stronger per unit weight. But if I ever build one from scratch I will use square, because I find it easier to weld.
    #3
  4. villageidiot

    villageidiot Long timer

    Joined:
    Apr 29, 2010
    Oddometer:
    2,441
    Location:
    Orange County, CA
    ive been on the hunt for a wheel to match my bonneville mag wheels. its also a pretty known thing in the bonneville community to put cbr600f3 wheels on the bike, so i may scoop one of those up if i can't find a matching mag wheel i can justify buying (trying to keep it pseudo cheap)

    i think that i will use round, as it looks nicer and no sharp edges, though square is easy to get things flat. im not a rookie by any means, but ive never built a sidecar, i have made bicycle frames, truck racks, bumpers, roll cages etc. i work as a mechanic restoring mercedes benz sl's

    thanks for the responses.
    #4
  5. Ivan Rider

    Ivan Rider Been here awhile

    Joined:
    Feb 19, 2008
    Oddometer:
    628
    Location:
    Bodega Bay & Galt. California
    I agree with the above posters but I'll add my 2 cents. On my Airhead rigs I used and liked having rear matching bike wheel and tire as a sidecar tire especially on long trips cross country. The pusher wears out faster then the rest so before it's all gone you can swap with the sidecar and get home without buy a tire on the road. On my BMW Cruiser rig I had a car tire on the pusher wheel that lasted 30,000 miles so I put a front wheel on the sidecar. On that rig the front tire wore out first and I could swap wheels on the road with the sidecar. I once had to go a couple hundred miles in the mid west to find a new front tire for that rig so that's why I went with a front for that particular sidecar rig.
    #5
  6. villageidiot

    villageidiot Long timer

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    Apr 29, 2010
    Oddometer:
    2,441
    Location:
    Orange County, CA
    thanks for that ivan, thats what im thinking.

    i doubt i could find a car tire as a pusher for my bonneville wheels, and a 15 inch conversion isnt happening.
    #6
  7. larrylarry75

    larrylarry75 Aye Chihuahua

    Joined:
    Feb 13, 2007
    Oddometer:
    322
    Location:
    Southern OR coast
    I've got 3 different tire/wheel combinations on my rig and it's never once been a problem. My hack's wheel is from a BMW that more or less matches the bike's and includes a disc brake operated by the bike's rear brake lever. Works fine, especially when descending in deep gravel, gives you lots more control. On longish tours I carry spare tires and don't worry about it, never had a flat yet.

    LL75 :evil
    #7