Thread: old old bike
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Old 03-28-2015, 12:24 PM
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boxcar boxcar is offline
Motorized Bicycle Elite Member
Join Date: Dec 2014
Location: Astoria OR
Posts: 358
Default Re: old old bike

You go girl.......

I wouldn't worry about restoring it to original- It should be a good motor anyway-

I'd use a 50cc for less weight and vibration , on a vintage lugged and brazed frame like that. The 3 speed frames are fairly beefy compared to a vintage road frame

I'd set it up with some modern alloy rimmed 700C wheels and go with about some 32mm wide tires (approx. 1 1/4 inches) with a good road pattern, not gnarly, for a smooth roll. I think three speed hubs can be hard to sprocket, and even then, an old one like that might be the weak link for problems later. Use the search engine here to research the topic if you are thinking of using the rear hub- I'd urge you not to, and to dump the fenders- they'll just be a clearance problem on this frame.

With a 36 sprocket rear gear- it would get you up to 25 mph nicely and yet still be lightweight
A smooth sided fixie hub can be drilled and directly bolted with some titanium bolts for ultimate weight savings

You may be able to eliminate the motor chain tensioner by matching the chains with half-links, but diamond frames have a little less chain clearance than cruiser frames, so keep the tires narrow.

I'd probably also try to get a new bottom bracket and spindle and a lightweight single sprocket alloy three piece crank. Those are usually about 46-44 teeth, so you'll need a 22 tooth rear pedal sprocket to give you a nice easy pedal,

a shock seat post is nice too and not that expensive, and with a good padded cruiser saddle it should be a fairly comfortable ride.

I'd use a smaller tank- pedaling can be a problem on a diamond frame, with the tank in the way
and they quit making an underbar tank years ago now.

You may want a rear rack tank or some other place like under the saddle.
And when you'r all done you will have a modern fixy or single speed diamond framed bicycle to motorize. Available at any retailer for just over $100.....

Not meaning to offend or be argumentative here BUT:
If it were me. Which it is not.....
And I was going to motorize a fairly rare rod brake roadster bike.
I'd figure out a way to do it without removing everything that makes it a fairly rare rod brake roadster bicycle.
After all, that's why it is so cool.....
I'm not a bicycle purest or snob.
I wouldn't be motorizing bicycles at all
if I were.
But there are limits to my insanity....
Happy Trails......
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