Columbia 1937 board tracker real gas tank

Discussion in 'Photos & Bicycle Builds' started by KCvale, Feb 8, 2015.

  1. KCvale

    KCvale Motorized Bicycle Vendor

    I normally don't build on ~$150 wally world type bikes but this caught my eye.
    http://www.walmart.com/ip/39801995?...7321352&wl4=&wl5=pla&wl6=105949407872&veh=sem

    The 'tank' is two pieces of pressed formed sheet metal that butt together in the middle via 2 struts attached to the frame via cut outs, two screws on each side plate, and top mounting hole to strut between the split top bar.

    [​IMG]

    I thought I'd see if I can make it wide enough to get a filler and petcock on it and seal it up like Sportsman does.

    [​IMG]

    I made new inner struts to widen the front 7cm wider and the rear 3.5cm wider.
    NOTE: flattening the front struts V mount out straight gives you the back strut.

    [​IMG]

    That leaves me enough room for the petcock, and with the wider front enough room for the filler I hacked off an old kit tank.

    [​IMG]

    I found a spiffy thinner steel filler and venting cap that that is pretty darn cool.
    If the bike falls over all you get is a little drip from the tiny vent hole as the cap is threaded with an O ring seal.
    http://www.ebay.com/itm/Custom-Fuel...h-weld-in-Bung-SMALL-CUSTOM-NEW-/191495380281


    For the petcock I'm going with the new MB kit one with the threaded collar so you can orient the valve lever and it has a double long inner screen with a Normal and Reserve setting.
    http://www.gasbike.net/gasoline-tank-switch-for-2.5-L-gas-tank.html

    Reserve on this flat tank should be enough for 10 miles or more.

    I got some poster board to cut out the templates for the sheet metal and thinking I'll just pop-rivet it on because I found this to seal up the tank.
    http://www.caswellplating.com/restoration-aids/epoxy-gas-tank-sealer.html

    A gas-proof liquid 2 part epoxy that creates a solid tank inside the shell.

    Under $100 to NOT use a peanut tank is worth it, and the bike itself has potential for handlebars down board tracker feel or sit up nice beach cruiser.
    Worth exploring for me ;-}
     

  2. Wolfshoes

    Wolfshoes Member

    This looks great. If the goal is to make a bike worth more than it cost to build, which seems harder to do than it sounds, you could be there. You are the best there is. Please forgive me for bringing it up but I hope you take your own advice and give this tank sealant system a good long vibration test before you release it to a customer. It looks so good making it painful to sell used, but it may be worth it.
     
  3. KCvale

    KCvale Motorized Bicycle Vendor

    Indeed that is the goal.
    An actual big working gas tank in the frame is the coveted tit's on an MB.

    The frame is pretty solid, nice thick steel, the rack is removable not part of the frame.
    And it has 3-piece cranks ;-}

    It has to be a 2-stroke, 4 won't fit (bummer) but with a shift kit and 3-speed back wheel quote a cool ride that will actually go well over 100 miles on a tank of gas, especially if you put the bars down like a board tracker to get aerodynamic.

    I will be double checking everything.
    I sell locally and inform my customers about everything, if this first tank leaks I want to know and I'll make it right for free.
     
  4. Sgt. Howard

    Sgt. Howard Member

    Bloody damn awsome!
     
  5. KCvale

    KCvale Motorized Bicycle Vendor

    I have my sheet metal templates cut out and test fit.
    I did it with just 2 pieces.

    This is a shot inside from the bottom with top piece on so you can see the 2 struts.

    [​IMG]

    The back strut is the original front strut flatted out.
    The silver front one is mine.

    The struts give the sides some structure and fills the 4 side holes with a bolt and cover.

    Both pieces have at least a 10cm lap everywhere.
    This the top.

    [​IMG]

    [​IMG]

    And the bottom piece.

    [​IMG]

    (cont...)
     
  6. PocketBiker

    PocketBiker Member

    KC,

    Thank you for telling me about your build site. You have really inspired me! Man, if you seal up that planned expanded tank, you will have fantastic range! Seems like it would be well over 2 gallons? I'm still kind of stuck on a fiberglass inner tank.. leaving room at the front and/or rear for oil bottles, tools etc. So, I will be tossing around the best way of opening one side, giving me access to fill the tank, oil etc. But, the sealer idea is really something!

    And that fuel petcock with a reserve position! Really great for such a large tankl!

    For a budget, I found this alum./steel cap assembly. The cap Dia. is only 1 5/8" and the knurled edge looks nice only $13 delivered. Not sure, you might have to drill a vent hole?

    http://www.ebay.com/itm/DOM-Steel-W...5&pid=100005&rk=3&rkt=6&sd=221428977021&rt=nc

    cap.png
     
    Last edited by a moderator: Dec 18, 2015
  7. KCvale

    KCvale Motorized Bicycle Vendor

    (...cont)

    It looks like it belongs there to me.

    [​IMG]

    I even kinda dig the top white accent but we'll see.

    [​IMG]

    Note the filler tube and cap I have sitting on the tank won't be used, it is an example of what to expect if you want to cut your stock engine kits tank up for parts.

    All I could get was ~2/3" of filler neck which puts the 2 1/8" cap right next to the top bar. No way to get grip around it.
    You would need to make front ~3/4" wider and it would work.

    The filler I have coming will fit pretty in that spot and be easy to operate and gas up.
    The petcock fitting is not going well, Cole is out fetching parts and is dropping my mock-up off at Jim's to have a look at it but the 1st hardware store didn't have a tread match for it.

    In the mean time the bike is being fitted with front and rear C-brakes with a dual pull brake lever for a 3 brake system, it's not a light bike and with over a gallon of fuel on board harder than most to stop.

    And mounting the engine...
    It is tighter than it looks.

    I have a couple shots of it in handlebar Board Tracker look I'll post later, not ideal handlebars.
     
  8. james65

    james65 Member

    Thank you for this great thread.
     
  9. KCvale

    KCvale Motorized Bicycle Vendor

    My pleasure PocketBiker, just sharing what I'm trying.
    I don't know how much larger than a full gallon it will end up, but enough bigger that you could pull up to a pump, put exactly 1 gallon in, and then just add 4oz (1/2 cup) of 2-stroke oil on the spot.

    Using the area for storage is certainly possible if you make it big enough, but I'm going all gas.

    I went with this $40 3 part Caswell epoxy tank kit
    http://www.caswellplating.com/resto...oxy-gas-tank-sealer-mini-kit-up-to-5-gal.html
    With shipping in was $57.

    Properly done it should make a nice completely self contained solid inner tank, struts and all.
    I was even thinking of maybe even putting a couple of big vertical fins on the struts to reduce the amount of 'fuel slosh' one might get with a long flat tank carrying that much fuel in stop and go traffic but I may be too late.

    I stopped by the metal shop around the corner and he said he had material for my templates and could button it up nice for $100.
    That includes putting in the petcock and filler bungs.
    He didn't know about that epoxy tank sealer stuff, that makes his job much easier, it don't have to be air tight.

    If the filler is the steel part that will work, and the price is right, but it's close to the tank and yes, just a little hole in the top.
    I went with a longer filler (1.5"x1.5") and steel venting cap 1 3/8").
    $30.

    [​IMG]

    You have 2 top bars so it's still pretty wide up in the front and you to be able to grip the gas cap, besides, I like a long filler neck to avoid spilling gas.

    I want to use this MB kit petcock with reserve but finding the right size pipe thread is proving difficult so far, but I'm not going to sacrifice a new tank for it.

    [​IMG]

    Standing straight up in that long flat tank it should have a dozen miles or more of reserve and room in the tank for exactly 1 gallon of new fuel.
    Ride until you hit reserve, drop another gallon in at the pump, easy ;-}
     
    Last edited by a moderator: Dec 18, 2015
  10. KCvale

    KCvale Motorized Bicycle Vendor

    Even a 2-stroke is a tight fit.
    You'll need an offset Z intake.

    [​IMG]

    The engine will go down to within a few mills of the chain guard for a bit more room but it's still going to a pretty short fuel line, possibly not enough for a fuel filter.
    The throttle cable may be problematic as well unless I can run it to the front between the split top bar.

    This what it looks like with the handlebars down.

    [​IMG]

    Not my style but there it is.
     
  11. PocketBiker

    PocketBiker Member

    Tight fit!

    KC,

    Did you have to use Vaseline to install that engine? That is "scary tight."

    Oh, what a tangled web, we weave! The offset intake manifold is a nice solution. And, thanks for the heads up on that throttle cable... I'm guessing I can bring it up over my tank. But, that's another knuckle-biter! Boy, I think that they made slant heads and offset manifolds, just for us!! :grin5: No room for rubber motor mounts! Even the fuel line is sketchy, huh?

    I don't have my engine yet, but I was planning on cutting out a 2" square from the peanut tank's petcock fitting and glassing it into the bottom of my tank. I believe that will be a threaded brass tubing?? Does that sound feasible? The outlet and carb. are right there on top of each other. Too close for comfort!

    I drive through Phoenix in April..... I would sure like to buy you lunch! (I think I owe you lunch and dinner for all the help you've given me so far) I don't think I would make it through this project without you forging a path!! :sweatdrop:

    Would I be asking for your best fishing hole, if I asked you to suggest a good choice of a 66cc engine. BikeBerry is $160. I know half the kit will be tossed but the muffler almost makes the kit worth it.

    Oh, I spent the day (here at work) laying out the size of my tank on a template. Talk about FUN!!! Must have looked pretty funny, with my two tank halves on my desk! :devilish:

    Jim

    Jim
     
  12. KCvale

    KCvale Motorized Bicycle Vendor

    Actually not that bad.
    I had to get a longer U-bolt for the front mount.
    Plate and hardware from SBP front mount.

    [​IMG]

    [​IMG]


    Yes, right along the side of the top bar.
    The tank is inside the top bars where the carb is so it will ride on top of the tank to the front from there.

    It's a flat bottom tank, you can put the petcock wherever you want.
    I am figuring between the carb and head.

    I still can't find a piece of threaded pipe that fits the petcock or even a die to make one!
    Damn funky threads, I may have to opt for a motorcycle petcock or sacrifice a tank.

    It's coming along.

    [​IMG]

    [​IMG]

    Sounds fun, let me know when your in town.
     
  13. KCvale

    KCvale Motorized Bicycle Vendor

    Here are couple of shots while I wait for parts for the tank.

    [​IMG]

    I would have liked to have put a long chrome Poo-Poo pipe on it but this tank is costing more than I wanted to pay already so I'll just bend that stock pipe up some.

    All the cables and wires diapered and yes, a keylock ignition in addition to the throttle kill button ;-}

    [​IMG]

    Dead level NT carb with good air filter, rock solid engine mount, true chain line with no tensioner, and the throttle has that quick audible snap-back click when you let of the throttle at wide open.

    Front and rear C-brakes to assist the coaster brake and of course BMX foam grips to dampen any vibrations.

    [​IMG]

    It should be quite the machine with the big tank in don't ya think?
     
  14. Wolfshoes

    Wolfshoes Member

    Your bike is looking good! However, since you asked, I'm not happy with your front motor mount. I had a similar one. Not from Sick Bike Parts. It broke without warning becoming a total front mount failure. The engine will swing around. The chain bending sideways will seize around the front sprocket. Even a low speeds it can badly in not permanently bruise the side of your knee. I suspect at higher speeds the chain could pull the engine completely off the bike taking out your knee on the way by. The case could be made this is even more dangerous than a tensioner falling into the spokes.

    100_0678.jpg

    The rectangular bracket was sent as the large tube equivalent part from Gas bike. It looks to me to be the stronger part. Rather than repair the front mount with similar replacement; I made a different attachment of the motor to the bike frame.

    100_0679.jpg

    The exhaust support also acts as a backup engine support in the event of a front mount failure.
     
  15. KCvale

    KCvale Motorized Bicycle Vendor

    I have 100% confidence in my motor mounts or I wouldn't use them.
    It passes every test I do, if it moves AT ALL pushing as hard as you can it's a fail.
    This doesn't fail and looks a whole lot better than some plywood bolted to the side don't ya think?

    I do and you can always give me **** if the tank don't work out, for now it is one mechanically solid safe machine.
     
  16. butre

    butre Well-Known Member

    the plywood looks a bit jerry rigged, but a sheet of aluminum in it's place could look good
     
    Timbone likes this.
  17. PocketBiker

    PocketBiker Member

     
  18. fattirejack

    fattirejack Member

    KC, not positive but I believe petcock is british standard pipe thread size -4
     
  19. KCvale

    KCvale Motorized Bicycle Vendor

    I have every intention of having some better fitting plates made for this frame for future builds just for the look, but I used what I have and it is rock solid, even a catastrophic chain lock at high speed will take out something else before that mount will budge including that plate.

    Thank you Jack, I'll see if I can find a die for that size and thread my own little piece of pipe for the tank outlet.
    I really like that style petcock for orienting it out in just the perfect place on the tank which will be important considering how tight the fit is.

    This build has been rolled aside until the tank is ready and a new build is in the stall so no real updates until I have the tank back.
     
  20. KCvale

    KCvale Motorized Bicycle Vendor

    The tank takes form

    The tank is back from the welders.
    I still need to seal it and do the finish work on the new metal but it follows my template well and fits in just like I wanted it to with the petcock I wanted where I wanted it as well as the filler.

    Here a couple of shots straight from the welders.
    They used overkill thick steel but it sure makes for a solid structure.

    [​IMG]

    [​IMG]

    The important part was it could slide into the frame so I took the whole bike up there.
    That really paid off as it fits just as well as the template pieces I took them did.

    [​IMG]

    [​IMG]

    [​IMG]

    Unlike most of the US today it will be a nice sunny 80F here in Phoenix today so I'll put the tank out in direct sun this afternoon to preheat the whole tank to 90+F and then run a solder bead with my electric iron along the seams to semi-seal it and then start the 3 part tank sealing treatment.

    It's been a pricey endeavor for me, $250 to the welding shop, $50 for the petcock and filler, and $40 for the tank sealer but you home built guys..
    Some medium sized sheet metal cut to the template and just pop riveted in would save you a bunch.

    All I know is it can be done and I'm digg'n the look ;-}
     
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