When I posted the first article on gearing a week ago, it was not my intention to extend it into a series. However, it is a subject that has caused me to reflect on how things were, and to speculate how we arrived at where we are today.
Going back to the turn of the last century, because Britain was initially the center of the bicycle industry, the bicycle chain was quickly established at half an inch pitch. It has remained the standard worldwide ever since, even in countries where the metric system has always been in place.
Although chains are made in all manner of pitches for industrial use, ½ inch pitch has always worked fine on bicycles, and there is little reason to change it. I seem to remember Shimano introduced a one centimeter pitch chain for track bikes back in the 1980s, but it was short lived.
Sprocket and chain width was set at one eighth of an inch, and remained so for 50 or 60 years. The introduction of the five-speed freewheel made it necessary to make the sprockets narrower, and the 3/32 inch wide chain came into being.
The six-speed freewheel was introduced (I believe.) in the early 1970s, and was achieved by widening the spacing between the frame’s rear dropouts, from 120mm. to 126mm.
This remained the standard set up until about the time I left the bike business in 1993. I know this because all the frames I built in the US had 126mm. rear spacing.
Soon after gears quickly went from 6 to 7, 8, 9, and 10 speeds; and with it 130mm. rear spacing; all within a relatively short span of years, considering how long the 5 and 6 speed was the standard.
The reason this came about? Index shifting, MTBs and the power of the American market.
I remember when Shimano first introduced index or click-shifting in the late 1980s, I was one who scoffed at it, along with most Europeans.
I remember talking to people from Campagnolo and they likened the idea to “Putting frets on a fiddle.” A violin has no markings where to place your fingers to play a given note; throughout history people learn by experience where to place their fingers.
It was the same with shifting gear on a derailleur. People like me who grew up using friction shift gears could not understand why anyone would want to complicate something so simple.
Of course the mountain bike was a whole different story, down tube shifters were not practical, and it lent itself to a ratchet type, handlebar gear control. Also, here was a whole new generation of users not raised on the traditions of road bike use.
Throughout history, the design of the racing bicycle, and its components, was always dictated by what the European professional riders used. The MTB was an American phenomenon and the rules changed.
I remember Campagnolo lost a huge share of the component market in the US to Shimano, because they were slow to get into index shifting, and spent several years playing catch up.
Click shifting made it possible to go up to 10 speeds. Although it may have been possible with friction shift; never-the-less it would not have been practical.
One commenter asked if riders were stronger in the old days; I don’t think so, we just made do with what we had.
The Tour de France was run on single gear bikes up until the late 1930s, and the riders went over the same mountains they do today; plus the roads were often no better than dirt tracks.
Our top gears were in the 90s, but we trained on very low gears and so learned to pedal fast. At the other end, I never had a gear that was lower than 50 inches, and never found a hill I couldn’t climb on it.
I was always taught that in terms of energy spent it was better to climb a hill on the highest gear possible. I don’t know how that jibes with today’s thinking, but when 50 inches was your lowest gear you had no choice but to stay on top of it and keep the revs at a reasonable level, or you were finished.
With today’s gears in the 30s and 40s, it is only natural that you are going to use them, and spinning a low gear on a steep gradient is exhausting.
I am not talking of a slow walking pace, but one of racing speeds. It takes a special rider of great stamina to do that
Top picture is my current set up. I was lucky enough to find a 48 chainring on eBay; it was actually an inner ring, but works fine as an outer. The inner ring is a 39. With a 14 to 19 straight up six-speed freewheel it gives me gears from 92 to 55 inches. Pretty close to the range I had in the 1950s