The Light Roadster
In terms of thinking about styles of bicycle, several main types come to mind. People think of the "heavy weight" balloon tire bikes of the 1930s-50s, the lightweight 10 speeds and derailleur bikes of the post-World War II era, the antique/wood wheel bikes of the pre-1933 period, etc.
In terms of utility cycles, let's think about the overall "3 speed roadster family" of bicycles. Sheldon Brown once set out the basic divisions of this family of bicycles when talking about
English three speeds. He roughly defined a
light roadster as having 26 1-3/8 or 26 x 1-1/4 wheels, metal fenders and utility accessories, a 3 speed hub (usually Sturmey Archer), and sharper/nimbler frame angles than a longer, full roadster. The
full roadster often has rod brakes, a full chain case (though not always) and 28 or 26 x 1-1/2 inch wheels/tires (though not always). Thus the "light roadster" is exactly what its name implies: a lightened and nimbler version of a utility bicycle.
A Quick Study in Contrasts and Hybrids
Full Roadsters:
A 1978 Raleigh DL-1 roadster: 28 inch wheels, rod brakes, slack frame angles. This epitomizes what Sheldon Brown referred to as a "roadster", even if it lacks a full chain case.
"Vintage Hybridized Roadsters"
Some bicycles display elements of both the "light" and full roadsters. To differentiate these bikes from today's "hybrid" or "comfort" bikes, let's call these "vintage hybridized roadsters".
Raleigh Dawn Tourist: a Raleigh Sports (light roadster class) frame, but rod brakes, full chain case, and lots of accessories. It's more "roadster" than "light", but you can't ignore the frame dimensions, which are "light" roadster class.
Hercules Model C: full roadster slack frame angles, but "light" roadster style 26 x 1-3/8 wheels and lower bottom bracket of a "light" roadster class bike. It's almost a perfect hybridization at the 50/50 point.
Light Roadsters
The "light" roadster is epitomized by the Raleigh Sports: cable brakes, 26 x 1-3/8 wheels, nimbler frame angles, and different frame construction types on the back triangle.
This 1958 Raleigh Sports 4 speed is the quintessential light roadster.
This Raleigh Sprite 5 speed is a "high performance" light roadster variation. It bridges the gap between a 10-speed "light weight" or "road bike", and more traditional light roadsters like the Raleigh Sports. I think the Sprite is more a light roadster with a little more "oomph".
An American light roadster: the Schwinn New World: cable brakes, frame angle nimbler than a roadster but slacker than a Raleigh Sports, 26 x 1-3/8 x 1-1/4 wheels (comparable to a Raleigh Sports).
This bike has a nice, fillet brazed frame as well. It's notable that American light roadsters can come with three speed hubs, coaster brakes, two speed "kick back" hubs, two speed "lever actuated" hubs, and a wide mix of parts. These are variations, but remain "light roadsters" at heart.
Why was the Light Roadster So Successful?
I think the light roadster's success over the years comes from finding just the right balance of utility, sturdiness, weight, and handling. The light roadster can be lifted and carried up the steps of your house more easily than a full, Raleigh DL-1 types roadster. The light roadster's cable brakes or cable-coaster combo provide reasonable stopping power without the added weight of rods. The nimbler frame angles make the bicycle more responsive, but remain open enough to be stable carrying a moderate load of rider and cargo. The fenders, chain guard, and accessories make the riding experience practical, but not overloaded.
In other words, I think the 'light roadster' bicycle is the product of experience. If the Raleigh DL-1 and other roadsters were the "Ford Model T's" of the bicycle world, then the light roadster is the "Model A": an improved but still simple vehicle born from experience in needing to improve on the original, full roadster design.
Closing Thoughts
If you're looking for a practice, attractive, and serviceable bicycle, a 'light roadster' is hard to beat. I tend to think of today's hybrid and "townie" bikes as the descendants of yesterday's Raleigh Sports and Schwinn New World or World Traveler 3 speed bikes. We've come a long way in materials and technology, but the basic concept of a balanced utility bicycle remains.