1950s-1960s road bike suitability for motoring

[andy b.]

In my searchings on Craigslist, I seem to find a lot of bikes that I would call road bikes from the 1950s and 1960s. These bikes usually have a 3-speed hub, or might be a ten speed on occasion. They don't have large tube frames like cruisers or mountain bikes, and I was wondering how well they would hold up with a small 2-cycle or 4-cycle engine mounted in them?

I see a lot of folks mention Raleigh bikes of that period. Are they of a better quality with a decent frame that would handle a motor being stuffed into it?

Thanks,

andy b.

 

[BarelyAWake]

Judging from what I've seen, frame quality & strength of that era's road bikes (name brand ofc) is a non issue in regards to the suitability of mounting an in-frame engine, regardless of type. Usually featuring fully lugged steel frames unlike today's alloys and exotic composites, strength was a primary consideration whereas today the focus is weight conservation. The Chinese two stroke is actually an ideal fit, the diamond shape of the frame and the small tubing perfect (earlier model in frame two strokes have the smaller mounts).

The problems are twofold, one being the crankset is far too narrow to clear the engine - not a major setback as there's wider 3 piece conversion kits readily available and it's inexpensive as well. The second is far more problematic - the rims are simply inappropriate for the added speed and weight, far too narrow and flimsy to take any sort of impact at speed they're sure to collapse and are a hazard.

Were you to find more suitable rims, double walled, laced w/heavy gauge spokes and as wide as will clear the chainstays & forks with tires that have enough sidewall to absorb some of the impact force of the inevitable pothole or obstacle, a road bike would actually make a fine motorized bicycle, in fact most likely quite a fast one too

 

[andy b.]

BarelyAW,

Thanks for the reply! I was thinking the lugged frames looked robust enough, as they seem pretty similar to the industrial Worksman frames. I'll have to see what can be found in the way of different wheels and better tires.

I found a bike from the mid-1960s that is close to me and a decent price. It has a SA TCW 3-speed coaster hub, but it has 40 spokes. It may give me a good winter project if wheels and tires can be found.

andy b.