1937 Columbia with Custom Tank

[KCvale]

I seen this Columbia Built 1937 26" coaster brake fax Board Tracker bike for $150 at Wally's and thought I see if I could make the fake thing a real tank AND fit a motor in the frame.

I'll get to the tank below but this is the build done and just awaiting the tank.

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 ;-}

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.

My custom tank using the stock side panels is awaiting the filler and cap parts but pretty cool and well over a gallon but it is a very long story of how to do it yourself that isn't complete yet.

I'll share the final details here but if you want to follow development my build topic is here http://kcsbikes.com/topic.asp?whichpage=2&TOPIC_ID=812

The big part was finding a way to structurally support the tank internally, but still have it totally seal inside and I found just the stuff, Cawsell Epoxy Gas Tank Sealer, this looks like the tit's of DIY tank sealer ;-}

The base is done, what do ya think?

 

[KCvale]

Here are couple shots of the stock side panels attached via a couple of internal struts and my white poster board sheet metal templates attached.

This is a shot of the 2 struts that attach to the stock side panel holes from the bottom with top piece on.

This is the top sheet metal template.

And this is the bottom sheet metal template.

I don't how much over a gallon the tank will hold or final cost but the bike is sound and what a boon for loosing the peanut ehh?

 

[Semaj]

Wish It was Electric :V

Totaly a sweet ride though! Im a bit on the fence about that fork though, are those chrome bars supposed to act like some sort of springer fork setup?


Hoely toledo! That tank really looks awesome!

 

[KCvale]

Wish It was Electric :V

Totaly a sweet ride though! Im a bit on the fence about that fork though, are those chrome bars supposed to act like some sort of springer fork setup?

Hoely toledo! That tank really looks awesome!

Thanks Semaj,
That cavity could easily accommodate a big LI pack and be electric.
I have a fat electric shifter I haven't sold yet however as it's in $1K+ range but this will be well under that.

This has been a fun project but I need to wrap it up pretty soon, my parts for the new 10G 4-stroke with long shaft for direct jackshafting are on their way and I haven't even picked a bike yet.

All fun stuff and we'll see how the tank works out.
All I know is if I can make a $150 bike into a $300 base with a huge in frame tank I'll sell a lot of them.

 

[Semaj]

I can dig the entrepreneurial venture here
Just be warned! Apparently if you dont have someone with a Motorcycle mech licence working on those bikes, prepare for potential suing by Further potentially injured peeps, (not that I dont think you are going to be making quality products)
The last 2 former local motor bicycle shops I talked to Said they both shut down due to Looming Potential Legal reasons... Not even anything that had come up, someone just mentioned to them that even with waivers signed on purchase, you could potentially have your pants sued off of you if you didint have some motorcycle mech present or working on said bike in shop.
Mayhaps thats just texas/austin, but Id definitely check up on it to avoid stupid headaches in the future due to other people.

Also you didint answer my question about the front fork :s

 

[KCvale]

Im a bit on the fence about that fork though, are those chrome bars supposed to act like some sort of springer fork setup?

No, the front struts, like the tank, are just for show, the front fork is a typical beach cruiser fork.

And I'm not worth suing ;-}

 

[KCvale]

The filler came in.

It could have been bigger, that might be a tight fit for a gas pump nozzle.

I found a British die set but not local and over $40, I'll just sacrifice a tank so I can get the parts up to welder today.
With any luck I'll have it back today or tomorrow.

 

[silverbear]

KC,
That's a great looking bike and I really like what you're doing with the gas tank. I've used that tank sealer and it is super. Your tank conversion has stimulated lots of thought about alternative ways of going about it. The thinness of the panels would be beyond my abilities to weld to it as I'm sure I'd burn right through it. I'm a poor welder, but I can solder like nobody's business. And I'm wondering if a person could get by with simply riveting the panels together or just tack welds. If the panels laid flat enough I think the tank sealer from inside would seal it all up with more than one application. Of course if you are selling the bike, as in your case, you want to be sure it is done right in the first place so it doesn't come back to haunt you later on. But for the home builder on a really tight budget it might be worth experimenting. I would try it with solder I think.

That's a lot of bike for the money. And yes, it would make a great e-bike. Well done, sir.
SB

 

[KCvale]

Thanks SB.
I figure it's worth a try, if it don't work out I can always put a peanut on it.
It's nice to hear a first account of the tank sealer kit I bought,

I just got back from the welders, took the bike up and left it so they could see where it has to go.

The original metal shell just barley fits in the frame.
In short you can't add anything on the outside (expect the right side) and expect it fit back in the cavity, so they are going to spot weld the plates on the inside.

(snickers) they had already cut out the templates using 18g steel, the tank wouldn't slide in with just the top on, let alone the bottom.

Anyway, they have everything now so we'll how it turns out ;-}

 

[silverbear]

I wonder how they will hold the plates in place while tacking them? Weld them from underneath? It would be interesting to know how they manage it. If from above then maybe a couple of magnets as anchors to pull them up snug. Or temporary anchors tack welded and then ground off once the pieces were joined. I saw Tinsmith do something like that with tabs of bent tin, shaped like an L with the short leg soldered down which gave something to lift with to snug up the matching surfaces. After the pieces were soldered together then he went back to the L tabs, heated them up to remelt the solder and lifted off the tabs. Pretty slick. With solder you would have to do the work from above. Interesting situation.
SB

 

[KCvale]

Now this is exactly what I had in mind for the tank.
The tank still needs a lot of work as does the exhaust and cabling, but I have the solid structure!

I ran out of daylight today but I'm going to set the tank outside tomorrow afternoon to heat it up well in direct 80 degree sunlight and then use my electric soldering iron to run a sealing solder bead along the seams to try to get it as water tight as possible before I start the tank sealing process.

All my fussing with the petcock and filler were worth it, and the welding guys did a good job of not screwing up the big stickers on the tank sides.

I'll put up some tank specific pics for you DIY guys, I have the raw shots and still have much work to do I'll snap pics of so I'll keep that all that together.

The main thing to me is it don't look like a bicycle with a motor kit slapped on it so goal achieved ;-}

 

[silverbear]

Looking good!
SB

 

[Semaj]

I really like this build!
Forgive me if it's a downgrade from the exhaust you have now as I'm very in the dark about these petrol peddlers, but what about a bent pipe that ran to the back of the bike?

Edit: I see you wanted one but we're restricted due to budget. What about conduit? Wouldn't that work for it, it's cheap too.

 

[KCvale]

Nice Poo-Poo pipes are ~$35 and it would already have one if I didn't have ~$350 into just the tank so far.

Here is shot of the bottom from the welders.

They messed up and put the 2 acorn nuts where the original bottom and front mounts were opposed to 4 acorns on just the bottom, a pair in the front and pair in back a bit wider than the lower bar so I just strap it in.

I'll have to decide if I want to just drill a couple small hole in the frame and put bolts through, or come with something else to keep the tank secure at the bottom.

They did the top right, the plate is inside the tank, the filler in the perfect place, and about 1/3 up from the back an acorn nut that matches the frames cross strut for a bolt mount.

They used some pretty darn thick steel for the 2 rusty looking pieces, the kind of stuff even 2 men and boy can't bend by hand.
The sides may only be chain guard quality steel, the structure itself is better than the frame ;-}

The next few days will be all about sealing it up.
Once it's air tight I'll paint the outside where it needs it and stick a fork in it.

 

[kevyleven007]

Your builds always look great! What is this " new 10G 4-stroke with long shaft for direct jackshafting " you speak of?? first I've heard of it but it sounds like a great idea.

 

[KCvale]

Your builds always look great!
What is this " new 10G 4-stroke with long shaft for direct jackshafting " you speak of?? first I've heard of it but it sounds like a great idea.

Thanks Kevy, I built to sell so I don't cut corners.

The new 10G transfer cases are for the HS 142F short shaft clutch attached 4-stroke engines I have been working with Don Grube on for a few months.

Like the original 4G the clutch bell is mounted on a bearing with a 20T T-belt pulley to a 100T freewheeling bearing secondary with 2 different output shaft lengths.

For starters they all have a straight keyed shaft so you can put the dual setscrew output sprocket (9T-12T) anywhere along the shaft you want it.
Or 2 sprockets, or a sprocket and a pulley, or?

Anyone that has ever dicked with the bushing and end screw on a 4G or 7G to move the sprocket will appreciate this change.

The long shaft version is a special project and the parts have been taking a world tour via UPS but on the truck for delivery today.

I'm designing a base mount with a carrier bearing on the right for direct output straight down to the pedals or back wheel for that matter.

I tried with an 20T/80T but there wasn't enough reduction and the shaft couplings didn't hold up.

That won't be an issue with an ~8" long output shaft from the 100T freewheel pulley ;-}

I'm gonna drop it in this new Fito sitting here and see how it works.

But back to this 1937 project...

Even with tank at just over 100 degrees sitting out in the sun I couldn't get a solder bead to take with my electric iron, so I've taped it up and gonna cross my fingers that this tank epoxy works.

I'm sure disappointed in this $52 Caswell kit though...
It was supposed to have a solvent and etchant included and all I got was this in the big boxes.

What a terrible waste of resources to ship a couple of bags of syrup not to mention $12.95 to ship all that waste.

ANyway, I'll take some acetone to the inside of the tank and give the stuff a try.
Needless to say I'll be bit more than pissed if it don't work as touted.

 

[KCvale]

Done.

I'm happy with the build but not thrilled with paying over twice what I paid for the whole bike to make the tank.
That's OK, I learned gas tanks and know what to on the next one ;-}

 

[KCvale]

Darn rain...
We haven't had a chance to ride this yet but I have had people by and they all seem to love it.
Costly the first time, but fun to make and show off ;-}

 

[Semaj]

Once it clears up you will have to let us know how it rides

 

[MotoMagz]

Next time try this. http://www.hirschauto.com/ALCOHOL-RESISTANT-GAS-TANK-SEALER/productinfo/GTS/ a pint will seall probly about 15 of those tanks.One step on and its done