Columbia Tank frame bike

Discussion in 'Photos & Bicycle Builds' started by Drunkskunk, Jan 30, 2010.

  1. Drunkskunk

    Drunkskunk Member

    2 years ago I posted on here about a Felt 1903 I was going to convert.
    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. :whistling:

    So I bought my self one of these:
    <a><img src="" 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.


  2. Huntington

    Huntington Member

    gas tank.. never done it myself but I have seen post about people converting felts, something to think about.

    the Expansion chamber is a good addition, I recommend sickbikes expansion.

    You wont fell the boost bottle too much, it will make your engine run a lil smoother and for the price I fell its a worthy upgrade.

    The nitrous kit, IMO, is a gimmick, there is no real way to increase gas flow to your engine, so the nitrous will just burn up your kit. Use at your own risk and post a review and pics if you do use it. Im interested.

    That bike is sweet, a nice boardtrack look.
  3. swifty

    swifty New Member

    an expansion chamber is the easiest upgrade to get a noticable increase in power. can be a bit noisy.nitrous is for people who cant build engines!!! nice bike,very cool. :cool2:
  4. stealthc9

    stealthc9 Member

    have you ever run nitrous on anything? Seriously ive run nitrous on every vehicle ive owned (even my happytime) it doesnt increase gas flow, and what you just said makes no increase gas flow you REJET your carb.

    Boost bottle WILL be felt if you do the exhaust as well. Rejet,Exhaust,boost bottle, and nitrous.then Add a 27tooth sprocket. spray at like 500rpms you'll be good.

    The 27tooth sprocket will give you a loss of tq, all the supporting mods and nitrous will help regain that tq. you'll have a CRAZY bike if you do that.
  5. Huntington

    Huntington Member

    To each their own my man, I do know a lil something about what I am talking, Ill avoid argument in favor of a peaceful thread. Nitrous is more complex then just pumping cold air in the intake... The kits are a gimmick .. I dont know what the range of the HT engine is but I think 500 is on the low side.
  6. stealthc9

    stealthc9 Member

    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'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

    and then theres one non adjustable but it has larger ports
    Last edited: Feb 3, 2010
  7. Drunkskunk

    Drunkskunk Member

    I recognise those 2 carbs. the first is a Dakar. its a clone of a doletto, and uses the same jets. popular with the Moped crowd. the second is the revised version of what I have. Its on a 50cc peugeot right now, and works great. it marks its teritory well, too. the needle is ajustable, even if the jet isn't but jets can be redrilled. Both good carbs.

    I'm only half serious about the NOS, though. looks amusing, and from the sound of it, it works, so probably worth the $40 just for the novelty.
  8. Drunkskunk

    Drunkskunk Member

    An issue thats come up,
    I have a Nexus 3 speed rear hub with the coaster brake.
    the sprocket from my old kit's center hole is too small to fit around the outside of the hub. I could cut the hole bigger, but I'm lazy, and that would take some serious time with the tools I have avalable.

    Are there any sprocket kits available for the multispeed hubs?
  9. 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.


    That is a way cool bike. One that I DREAM of finding some day! Enjoy it!
    Last edited: Feb 7, 2010
  10. Huntington

    Huntington Member

    Good explanation of the fuel control problem Motorbike Wanabe.
  11. stealthc9

    stealthc9 Member

    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.
  12. RacerRon

    RacerRon New Member

    Just a bump, wondering if the bike ever got built
  13. Drunkskunk

    Drunkskunk Member

    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.

    Attached Files:

  14. HeadSmess

    HeadSmess Well-Known Member

    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!
    Last edited: Aug 29, 2011
  15. IbedaYank

    IbedaYank Member

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

    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. 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?
    Last edited: Aug 29, 2011
  16. IbedaYank

    IbedaYank Member

    Last edited: Aug 29, 2011
  17. HeadSmess

    HeadSmess Well-Known Member

    may i recommend 1/4" hiten steel plate? :D
  18. IbedaYank

    IbedaYank Member

    gonna need more than just NOS to move all that extra weight..:bowdown:
  19. HeadSmess

    HeadSmess Well-Known Member

    *straps on an old ford with some rusty wire :whistling: