Columbia Tank frame bike

2 years ago I posted on here about a Felt 1903 I was going to convert.
But...
Honestly, the bike is such a work of art, I just couldn't cut into it. I enjoy it too much. Maybe way to much. I keep it indoors while the rest of my bikes sit in the garage. :whistle:

So I bought my self one of these:
<a><img src="http://i95.photobucket.com/albums/l130/geijin/Bike/columbia.jpg" border="0" alt="Photobucket"></a>

1954 Columbia, or close to that year. It looks nice but its a rust bucket, and well dented. I kind of like the rust and the dents, but I won't be ruining by putting a motor on it.

I had bought an 80cc kit from a local vedor for the Felt, but ended up robbing most of the kit parts to get a moped working (the carb in these cheap kits is supprisingly reliable, if not leaky) Enough parts were missing, and the kit used 6mm headstuds on the 80cc kit, so I found it cheaper to buy a whole new kit from Spookytooth. Besides, the new kit has a catalitic converter, so I can feel less bad about what 2 strokes to do the air :p

I do have a few questions.

Has anyone converted a tank like this to be an actual gas tank? Is it easier to just build a new tank?

Anyone use an expansion chamber exhaust on these HT motors? are they worth it?

How about these "power bottles" on the intake? do they make a measurable diffrence you can feel in the seat of your pants?

And, I know it's a noob question, but the power of Testosterone compells me.. does the Nitrous kit I've seen for the HT motors work at all?

Additionaly, anyone have any advice they want to share, or pics of similar Bikes converted, I would appriciate it.

Thanks.
 
Drunkskunk,

I would look at using one of Creative Engineering's hubs. He could probably make the hole the size you'd need if you let him know.

As for the nitrous debate. I appreciate that everyone has determined to keep the conversation civil, I think it's good for the thread.

Now, you can re-jet for the nitrous (because you really don't want to run it lean on fuel with nitrous) but, when you stop spraying, how do you lean out the fuel since you don't need that much fuel when not on spray? My experience is that compensating for nitrous by increasing the fuel that much would make the engine's power output counter-productive once you "lifted" the NOS button. Would it be rich enough to 4-stroke at WOT, and what about lower throttle settings? I've always preferred supercharging over NOS because it's not an "all or nothing" power adder, even at part throttle, you still get some benefit of the supercharger. You set NOS up for one senario, WOT, and use it only when the button is set on KILL. At least, sucessfully.

Drunk,

That is a way cool bike. One that I DREAM of finding some day! Enjoy it!

See and that is the only real down fall from nitrous...but also to add to that, honestly you dont need to make the bike SUPER Rich otherwise you risk killing the spark plug. But what I would say is it would take too much tuning to get the nitrous dead on. I mean Pistons and rings for these bikes are only like $30 shipped (but then again thats the 1/3rd the cost of the engine kits)...with the replacement engines only being about $60 its not bad.
 
Just a bump, wondering if the bike ever got built

No, Yes. Sort of.

5 speed rear with coaster brake was installed. Custom 50mm rim laced, varois mods to the frame started, and the forks were modified for disk brakes, more rake, and a much stronger dropout. I even have a mockup of the engine mount made to house the sick bike parts jack shaft.. not installed right now.

But I installed an electric motor in the front ment to pull the bike up to speed so I don't have to pedle start.... Only while testing it out, I found I like it the way it is .... Then the project stalled, life got in the way. I ride the bike fairly often, but its electric right now. Someday I'l get the real motor installed.
 

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nos belongs in one place only! the surgery! bit of giggle gas does wonders :)

i mentioned this elsewhere before.... a cheap airbrush. modified to become a carby, solely for the purpose of injecting NOS WITH the required amount of fuel.

makes sense? you just drill tap and screw in this "nos" carby. open the valve, and there you go. enriched mixture thats completely seperate from the standard carb.

and tuning it in can be fun!

hook up petrol line, hook up nos, open nos, slowly adjust fuel mix....get a lighter. wooompf! blooooowtorch! then its a matter of adjusting the fuel flow (you did include a needle valve didntya?) til the flames blue. not dirty yellow, and not invisible(ha ha!) but blue. like a blowtorch...

you do this on a bench, not on the bike unless you have about ten pistons and cylinders spare :)

just stick with an expansion pipe ;)

and who said 500rpm? cus my ht IDLES at 800rpm. cruising is around 5grand...


rust makes for REAL bikes!
 
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umm...nitrous isnt just "cold air". nitrous splits into oxygen and nitrogen. So the injection of nitrous oxide into an engine means that more oxygen is available during combustion. Because you have more oxygen, you can also inject more fuel, allowing the same engine to produce more power,and faster. Its not meant to "pump cold air".

500rpms is about where the happy time starts cruising (or when mine is set to) when u release the clutch after peddling. Nitrous will automatically rev your engine with out you opening the throttle.

So you're crusing and punch it as your going wot...you'll get up to speed fast (but its easy to over rev if u dont know when to stop spraying)

it will make up for the tq loss of the 27t sprocket which with the gear ratio, you'd get around 47mph MAX give or take.

im not sure what my 20" wheel will equate out to, i havent bothered with that yet.


also your wrong, there are ways of adjusting fuel
http://www.spookytoothcycles.com/component/virtuemart/?page=shop.product_details&flypage=vmj_ace.tpl&product_id=415&category_id=93

and then theres one non adjustable but it has larger ports
http://www.spookytoothcycles.com/in...id=93&vmcchk=1&option=com_virtuemart&Itemid=1

to bad a ht IDLES at 1400 rpm...and thats in the manual




quote...
12. If the rpm needs adjusting, turn the idle adjust screw (left side of carburetor) in or out slowly to obtain the proper idle speed of about 1400 rpm +/- 100 rpm To correctly break the engine in, Do not exceed 15 mph or 30 min. continual running for the first 50 miles during engine brake in. Engine will develop more power after break in.

http://www.grubeeinc.com/USA/STARFIRE SKYHAWK WEB INSTRUCTIONS.htm


yeah go ahead and hit nos right off idle....hope you have lots of spare parts

27 t rear sprocket... yeah sure...and what company sells one for a Ht motor kit ... rag joint mounted or otherwise and how many HP is that HT class motor?
 
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