It's easy to believe that all bikes made up to the early 1980's or so had round steel frame tubes that were 28.6 mm (about 1 1/8"), or thereabouts, in diameter. When I first became a dedicated cyclist in the late stages of the '70's Bike Boom, about the only bikes that weren't made with such frame tubes were "Chopper"-style bikes with stays and other frame members made out of flat bar stock or thin twin-lateral tubes.
Turns out, though, that there have been all sorts of variations of tubing diameters and shapes since the "safety" bicycle first appeared late in the 19th Century. Even before Cannondale and Klein started to make frames with oversized aluminum tubes, bike makers used larger-diameter tubes with thinner walls in an attempt to make bicycles stiffer and lighter. The problem with them was that knowledge of metallurgy (Reynolds 531 and Columbus tubings weren't created until the 1930's) and welding or brazing wasn't as advanced as it is now. So, frames built with large-diameter thin-wall tubing usually met early demises.
And frame tubes and stays did not start to deviate from having spherical cross-sections when mountain bikes and carbon-fiber frames reached the mass market during the 1980's and '90's. There have been many variations on tubing shapes and configurations. One of the most famous is, of course, the curly rear stays found on some vintage Hetchins frames. (Sheldon Brown prized his.) Other frame builders and bike makers experimented with tubes that were triangular or shaped in other ways in the name of aerodynamics. Of course, what those makers and builders soon realized is that, in the end, a bike can't be more aerodynamic than the cyclist perched atop it.
Then there were other variations that were made for no apparent reason. I get the feeling that the companies and builders that employed them were trying to make their bikes look "distinctive". In other words, they were probably little more than marketing gimmicks. But, I'll admit that some of them looked pretty cool, like this 1947 Monark Silver King with hexagonal (!) frame tubes:
The shape, and the stripes on the head tube, give the front an odd sort of Art Deco look
and the appearance of raw industrial power at the bottom bracket.
Whatever you think of the frame tubes, how can you not love a bike with a rear fender reflector like this?
Now, if the frame looks like it was made of aluminum, there's a good reason: It was. That, of course, begs the question of how the headtube and bottom bracket were joined to those hex-shaped tubes.
Well, they were neither welded nor brazed together. Nor were they glued ("epoxied") like the ALAN frames of the 1970's or Vitus frames of the '80's and '90's. Instead the tubes were "mushroom wedged" into the "lugs". I have not found anything that describes how "mushroom wedging" is done. I can only imagine.
As for the Monark brand: They should not be confused with Monarch bicycles of the 1890s which share one characteristic with Monarks: they were made in Chicago. (And you thought Schwinn was the only bike maker in the Windy City?) Monark of Chicago also should not be confused with Monark of Sweden which, to this day, continues to build bikes as well as mopeds and other items.
Monark Silver King Inc., as the Chicago bike maker was officially known, started off as a battery manufacturer early in the 20th Century and began to make bikes under their own name, as well as for house brands of Montgomery Ward and Firestone, in 1934. They made some of the most stylish and unique baloon-tired bikes of the 1940s and '50's.
Apparently, they stopped making bicycles--ironically enough--during the early 1970s, when the Bike Boom in North America was picking up steam. Rollfast, a manufacturer literally steps away from where the Twin Towers rose in New York, met a similar fate around the same time. The Bike Boom translated into sales mainly for "lightweight" (i.e., ten-speed) bikes and all but destroyed the demand for balloon-tired and middleweight bicycles, the mainstays (or, in some cases, the entire production) of companies like Monark and Rollfast.
Turns out, though, that there have been all sorts of variations of tubing diameters and shapes since the "safety" bicycle first appeared late in the 19th Century. Even before Cannondale and Klein started to make frames with oversized aluminum tubes, bike makers used larger-diameter tubes with thinner walls in an attempt to make bicycles stiffer and lighter. The problem with them was that knowledge of metallurgy (Reynolds 531 and Columbus tubings weren't created until the 1930's) and welding or brazing wasn't as advanced as it is now. So, frames built with large-diameter thin-wall tubing usually met early demises.
And frame tubes and stays did not start to deviate from having spherical cross-sections when mountain bikes and carbon-fiber frames reached the mass market during the 1980's and '90's. There have been many variations on tubing shapes and configurations. One of the most famous is, of course, the curly rear stays found on some vintage Hetchins frames. (Sheldon Brown prized his.) Other frame builders and bike makers experimented with tubes that were triangular or shaped in other ways in the name of aerodynamics. Of course, what those makers and builders soon realized is that, in the end, a bike can't be more aerodynamic than the cyclist perched atop it.
Then there were other variations that were made for no apparent reason. I get the feeling that the companies and builders that employed them were trying to make their bikes look "distinctive". In other words, they were probably little more than marketing gimmicks. But, I'll admit that some of them looked pretty cool, like this 1947 Monark Silver King with hexagonal (!) frame tubes:
The shape, and the stripes on the head tube, give the front an odd sort of Art Deco look
and the appearance of raw industrial power at the bottom bracket.
Whatever you think of the frame tubes, how can you not love a bike with a rear fender reflector like this?
Now, if the frame looks like it was made of aluminum, there's a good reason: It was. That, of course, begs the question of how the headtube and bottom bracket were joined to those hex-shaped tubes.
Well, they were neither welded nor brazed together. Nor were they glued ("epoxied") like the ALAN frames of the 1970's or Vitus frames of the '80's and '90's. Instead the tubes were "mushroom wedged" into the "lugs". I have not found anything that describes how "mushroom wedging" is done. I can only imagine.
As for the Monark brand: They should not be confused with Monarch bicycles of the 1890s which share one characteristic with Monarks: they were made in Chicago. (And you thought Schwinn was the only bike maker in the Windy City?) Monark of Chicago also should not be confused with Monark of Sweden which, to this day, continues to build bikes as well as mopeds and other items.
Monark Silver King Inc., as the Chicago bike maker was officially known, started off as a battery manufacturer early in the 20th Century and began to make bikes under their own name, as well as for house brands of Montgomery Ward and Firestone, in 1934. They made some of the most stylish and unique baloon-tired bikes of the 1940s and '50's.
Apparently, they stopped making bicycles--ironically enough--during the early 1970s, when the Bike Boom in North America was picking up steam. Rollfast, a manufacturer literally steps away from where the Twin Towers rose in New York, met a similar fate around the same time. The Bike Boom translated into sales mainly for "lightweight" (i.e., ten-speed) bikes and all but destroyed the demand for balloon-tired and middleweight bicycles, the mainstays (or, in some cases, the entire production) of companies like Monark and Rollfast.
