11-28-2017, 10:23 PM
I've been reading "The Dancing Chain" by Frank Berto over the past few weeks, and while it focuses mainly on the evolution of the derailleur, it gives an excellent overview of the history of the bicycle.
In the late 1800's, the most common type of bicycle was the Pennyfarthing. You know it - the one with the giant front wheel, and tiny rear wheel, with fixed pedals up front. They were sized based on the diameter of the front wheel. This determined a couple of things, given the selected circumference: how fast you would comfortably ride, and how much effort you'd have to put in to do so. If you lived in a hilly area, you might prefer to take it a little slower because it is easier to pedal up steep inclines with a smaller wheel. Or, if it was flat and smooth, you might be fine on a 60" and zip along as fast as you could go.
When the chain-driven "safety bicycle" (looking much closer to today's bikes) was introduced toward the end of the 1800's, people were so familiar with this method of sizing that manufacturers came up with an equivalent direct-drive number by factoring in the ratio between the front chainring and rear sprocket. A bike with 20" wheels but a 30t chain ring up front and 10t chain ring down back would result in a 3:1 ratio, and would end up being a 60" equivalent bike.
I think this is absolutely fantastic, and I love the fact that it's a dead-simple way to assign a single number or value to the relationship between effort and speed. It's impossibly difficult to do today when buying a bike - you need to know the diameter of the tires, the chain ratios, and work it all out to figure out if it makes sense for you or not.
So, long story short, this got me thinking about my own bikes, and I was curious what their equivalent sizes would be, in 1800's terms. So, here it is:
In the late 1800's, the most common type of bicycle was the Pennyfarthing. You know it - the one with the giant front wheel, and tiny rear wheel, with fixed pedals up front. They were sized based on the diameter of the front wheel. This determined a couple of things, given the selected circumference: how fast you would comfortably ride, and how much effort you'd have to put in to do so. If you lived in a hilly area, you might prefer to take it a little slower because it is easier to pedal up steep inclines with a smaller wheel. Or, if it was flat and smooth, you might be fine on a 60" and zip along as fast as you could go.
When the chain-driven "safety bicycle" (looking much closer to today's bikes) was introduced toward the end of the 1800's, people were so familiar with this method of sizing that manufacturers came up with an equivalent direct-drive number by factoring in the ratio between the front chainring and rear sprocket. A bike with 20" wheels but a 30t chain ring up front and 10t chain ring down back would result in a 3:1 ratio, and would end up being a 60" equivalent bike.
I think this is absolutely fantastic, and I love the fact that it's a dead-simple way to assign a single number or value to the relationship between effort and speed. It's impossibly difficult to do today when buying a bike - you need to know the diameter of the tires, the chain ratios, and work it all out to figure out if it makes sense for you or not.
So, long story short, this got me thinking about my own bikes, and I was curious what their equivalent sizes would be, in 1800's terms. So, here it is: