Options for a Columbia Sports 3 speed bike?

Jon Allen

New Member
Jun 18, 2018
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So I got this crappy old columbia that i want to motorize but im not sure how to go about fitting her up. My main concern is with the internal gear hub I suppose. Im sure it wont hold up and i know there are better options as far as bikes to motorize but my other half likes the bike and i want to suprise her. I dont rly know where to start.
 

crassius

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Sep 30, 2012
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coming here, reading a lot, and looking at pics is a good place to start

bike gears don't matter much unless you plan on adding a jack-shaft kit

brakes always matter tho
 
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Nashville Kat

Well-Known Member
Apr 20, 2009
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If this project is still underway, your best bet might be a Top Hat design hub adapter and sprocket, but taking care to get the right diameter- most people get a coaster brake size - a three speed is a larger diameter and harder to find, the vendors used to be more specific, but usually still carry the size- you might have to request. I'd recommend about a 36 t sprocket and that would get you into the low to mid 20's mph range with no special heads or carbs or mobs, except maybe a short intake to prevent bogging down,The frame is probably a direct bolt on for a China Girl if that's what you're using - no need for any special adapters for larger tubes.

A 50 cc might be a better option than a 66- the clearances of the chain stays might be tight. You can also probably use 700c wheels on a 26 x 1 3/8 frame with little issues otherwise- the brakes may need to be switched, but probably not.
That would give you more options for tire width, although the three speed tires aren;t a bad roll, the rims are almost always steel, while 700's would be alloy and much lighter.

If there is any problem with crank width, you might also convert the BB to a three piece crank, where you can get really wide spindles, and put some kind of square taper crankset on- that might weigh less.

A tear drop tank on a diamond frame is in the way of peddling just a bit, defeating the purpose of having 3 speeds i think. the next best option may be a small and light one liter plastic tank on a rear rack- you'd have to use an inline petcock valve instead of one that screws into the tank

If you went with 700, I'd look for a lightweight 5 or 6 speed freewheel cluster, and put a very light $10 (new, on ebay) derailleur that also acts as a chain tensioner on the pedal side, or you'll have to match the chains with a single freewheel.

good luck
 
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