Attach a Motorcycle Gas Tank to a Bike Frame Tutorial

Discussion in 'Painting, Welding, Bending and Gas Tanks' started by jackal_lantern, Aug 10, 2011.

  1. jackal_lantern

    jackal_lantern New Member

    I decided for my second build I would like a bigger gas tank on my bike because I live in an area with a lot of hills and tended to fill by 1/2 gallon tank up more then I'd like to. On top of that, I love the look of a bike with tank set into the frame that you can only get with motorcycle tanks on the market. The big challenge to adding a motorcycle tank is the fact that motorcycle frames are a lot bigger than bike frames.

    Luckily, I've devised an easy method to remedy this problem if you have the correct tools.

    Note: pictures numbers below are for the order they were uploaded in, not the file name.

    Tools you need:
    Welder, metal cutting wheel, drill press, metal grinder or dremel sanding tool, 1/4 screw Tap tool.

    1"x1/8" steel strip, 1/4" nuts and bolts, 1.25" electrical pipe clamp (picture 4), (optional inner diameter 1.25" foam insulation tubing.)

    1) Buy Gas Tank that you like for your bike. I suggest looking for local Motorcycle Salvage Yards. If you are in the Inland Empire around Riverside I highly recommend Neanderthal Cycle Salvage. Try to get a tank that is not rusty inside, but if it can't be helped, this is a great product.:

    Make sure the Gas Tank is metal and has the same u shaped pieces of metal inside the part of the tank that cradles the frame as seen in picture 1.

    2) Measure the distance between the sides of the tank that will cradle the frame and cut a piece of the 1"(wide)x1/8"(thick) metal strip to fit in the tank (picture 2) and rest upon the U shaped metal pieces inside the tank crevice as seen in picture 3.

    3) Drill a 1/4" or slightly bigger hole through the dead center of the cut strip of metal.

    4) Grind/sand the edges of the metal strip and the surface of the tank you plan to weld and weld it in the position seen in picture 3! BEWARE, THE TANK METAL IS VERY THIN AND YOU RUN THE CHANCE OF BURNING A HOLE THROUGH THE TANK WHILE WELDING.

    5) Find a 1/4" bolt that will slip through the hole on the metal strip and can feed through the top of the 1.25" (or equivalent for your frame) clamp found in the electrical section of the hardware store (picture 4.) Make sure the bolt is also short enough to not block the clamp from going around the frame. Attach the frame mounting bracket to the tank with the appropriate nut so that you tank looks like picture 5.

    6) Most tanks I have seen also have a metal tab at the rear. measure the center of this tab and drill a hole slightly bigger than 1/4" (picture 6). This may be tricky considering that you have very little area to work with. Also make sure that by drilling the hole you have enough room for the bolt head to fit flush with the tab and not get stuck and dig into the tank.

    7) If you decided to buy the insulation tubing mentioned above in materials, put it around the frame to keep the tank from scratching your frame as you mount it and position it where you would it to be placed. Once you find the right position, clamp it down and draw a mark on the bike frame through the 1/4" tab in the rear.

    8) Take the gas tank off and drill part way into the frame of the bike with a drill bit the size below 1/4". Be careful to line it up with the angle the bolt will be going through the tab and into the frame. Tap this hole with a 1/4" threads for the 1/4" bolt.

    9) Reattach the gas tank with both the front clamp and screw in a 1/4" bolt through the rear tab and into the frame (picture 7.)

    You're Done.

    The steps to doing this are pretty much logical, but its good to read through before sitting down to do it. It took me about 1 hr trying to figure out everything as a went a long so it will probably take everyone else less.

    Total Costs: Gas Tank: $55, Bolts and Clamps: $3.00...hopefully you have all the other tools.

    Attached Files:

    Last edited: Aug 11, 2011