Retrotechtacular: How A Bicycle Is Made

Does your bicycle master boardwalk and quagmire with aplomb? If it was built by the Raleigh Bicycle Company, it ought to. This week’s Retrotechtacular is a 1945-era look into the start-to-finish production of a standard bicycle. At the time of filming, Raleigh had already been producing bicycles for nearly 60 years.

The film centers on a boy and his father discussing the purchase of a bicycle in the drawing office of the plant where a bicycle begins its life. The penny-farthing gets a brief mention so that the modern “safety model”—wherein the rider sits balanced between two wheels of equal size—can be compared. The pair are speaking with the chief designer about the model and the father inquires as to their manufacturing process.

We are given the complete story from frame to forks and from hubs to handlebars. The frame is forged from high-quality steel whose mettle is tested both with heat and with a strain much greater than it will receive in manufacture or use. It is formed from long pieces that are rolled into tubes, flame sealed at the joint, and cut to length. The frame pieces are connected with brackets, which are formed from a single piece of steel. This process is particularly interesting.

The brackets begin as a flat piece of metal. This piece is shaped into a bowl, and then the bowl is drawn into the shape of a Collins glass. Bumps are raised in the next process, which eventually are pierced and then shaped into an open cylinder much like a piece of pottery is hollowed on a wheel. This way there are no joints, just a single piece of strong, lightweight, dependable steel.

To make them even stronger, they are pressed in a jig. Then, the tubes that make up the frame are added and pegged through the bracket. The entire frame goes into a furnace for final tempering and is then cooled and cleaned. The extraneous brass from the braising process is removed, and the frame is electroplated.

A bicycle’s front fork is made similarly, but because it must absorb more shocks from quagmire, it has to be stronger and is formed as a single piece. After it is furnace-strengthened, both it and the frame are polished with emery cloth and on emery wheels so that the enamel will stick smoothly and evenly. The frame and forks are then rustproofed and dip-enameled for luster.

The kid is particularly interested in handlebar construction. These are shaped and bent to a set design on a machine, plated in a bath, and polished to a weatherproof shine. Fenders—or mud guards as they are called here—are formed in one fell swoop from strips of steel. The pedal cranks, chain wheel, and hubs are next. Pedal cranks are forged and cut and the various holes are bored and threaded. A special milky fluid cools and lubricates them afterward. Chain wheels are made from a piece of flat steel that undergoes a few pressings and turn it into a nice filigree. The pedal cranks are fitted to the gear wheel, and the hubs get grease-packed bearings.

Spokes are made on a single machine that cuts, hooks, and threads them. They are fitted first to the hub and then attached to the rim. The spoked wheels are tested for trueness, and any loose spokes are tightened. After this, tires and tubes are fitted to the rims.

The bicycle parts are finally ready for the assembly line, quality checks, and final adjustments. We return once again to the chief designer’s office, where he concludes that quality materials and constant checks throughout the process make for a bicycle that is second to none.

[Thanks, Luis]

Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.

24 thoughts on “Retrotechtacular: How A Bicycle Is Made

  1. This video sort makes a point abut the importance of documenting how-it’s-made videos for the future. For instance, the machine used to cut the gears for the pedal crank does in a few seconds what it takes me an hour to do on my CNC machine. Yes, it’s just a simplified shaper, but it’s a good reminder how to do something with incredible efficiency.

    1. yes but remember it’s one thing to use a shaper to make a pretested pre calculated and most of all fast mass replication of the same part where a cnc can produce multiple variants or different sets that do not as of yet require hundreds or thousands per day of the same component.

      it can take a few man hour days to configure one of those shapers for a single task but wonce done it will outrun any CNC mill where a CNC mill can start production emeditly slower yess but when you only need a small volume much much cheeper.

      And once tested approved and once the parts are tested you can use that same cnc bill to start producing the custom components the shaper will need to do it’s job :)

      1. You make a solid point why change is not always good. Using a CNC to do the job of a shaper just because it’s the newest greatest thing is costly. Using a CNC to prototype newer products is the proper place of the technology.

        However, if you had a CNC that could outperform the shaper both in production and cost effectiveness, then you would have a valid reason for replacing the shaper with a CNC.

        In all cases, one must analyze the tool for it’s proper placement int the industry and field.

  2. Excellent. I seem to remember somewhere raleigh had that largest factory in the world at one point. Its easy to see how when short of a blast furnace they truly do make the entire bike. It also explains why there are some odd raleigh only head set sizes and bb sizes. When you make every thing you can do what you want.

  3. I could be mistaken, but this may have been here before, but no big deal if it was. Looks like that the stationary jaw of the vise in the lead photo had been repair ed at least once once. I have a bike in the shop that was the dail transportation of the old man who used to be the bike mechanic in our small rural town. I wouldn’t be surprised if it was an English manufactured bike I never have dug it out to check for sure. however it would need som serious restoration. it’s been at 20 year since it had been used. Because of a brain injury I’ll never ide a bike again I tried to give it away, but no one was interest to see if it was good enough to work over. No doubt it need new rubber etc., but the basic structure should be fine.

  4. I once owned a 1959 Triumph 3 speed bike. It was a trade in at the bike shop I worked at in 1986. I bought it for $50. It was ALL original except for the tires and brake pads. It was in perfect condition. Black with gold pin striping. I knew it was made in 1959 because the Sturmey Archer 3 speed hub had the manufacture date stamped on it. I sold it a year or two later and I’ve regretted doing so ever since. :)

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