What is the most influential and important development in the history of the bicycle?
Some would say, well, duh, it's the invention of the bicycle. I might agree, except that it's hard to pinpoint when, exactly, the bicycle was "invented". Is Leonardo da Vinci responsible for it? Or, do you consider the "celerifere" the first in the line of two-wheeled vehicles we love to ride to day? Some might say Karl von Drais de Sauerbrun, who attached a steering device to his two-wheeler, is the progenitor of our pleasures. Then again, others would have us believe that it wasn't really a bicycle until Kirkpatrick MacMillan attached foot pedals to it.
After the invention of the bicycle, however you define it, probably the most important development--and certainly the one most influential beyond the world of cycling--is that of the pneumatic tire. Without it, not only bicycles, but also motor vehicles, would give slower and bumpier rides than wooden- or metal-wheeled horse-drawn carriages. And modern passenger aircraft could not take off or land.
Possibly the next-most important development is the invention of the "safety" bicycle. It's what we (well, most of us, anyway) ride today: two wheels the same size (or close to it), foot pedals and a front chain that drives a rear cog via a chain. This type of bicycle replaced the high-wheeler or "penny farthing" bikes, on which the pedals and cranks were attached to the front wheel axle. The gear ratio was, therefore, dependent on the size of the front wheel: Common diameters were 60 and 72 inches. On the "safety" bicycle, variable gears were possible.
Variable gears led to inventors coming up with various ways to use them, the most common of which are variable-gear internal hubs (e.g., the Sturmey-Archer three-speed hubs found on classic English bikes) and derailleurs.
About the latter: The patent for what is, arguably, the most important innovation in derailleur design was filed fifty years ago this month in Japan, and a month later in the US.
Here we can see it advertised in the December 1964 edition of New Cycling magazine:
It's the SunTour Gran-Prix derailleur, the progenitor of every single derailleur with even the slightest pretense of quality made during the past few decades.
This brainchild of Nobuo Ozaki, SunTour's chief engineer at the time, the SunTour Gran-Prix introduced the "slant parallelogram" design to the world. The derailleur's main parallelogram is more or less parallel to the chainstay, in contrast to those of Campagnolo and Simplex derailleurs, which dropped straight down from the frame mount and were almost perpendicular to the ground--or those of Huret derailleurs, which consisted of flat steel plates that pivoted on the mounting plate.
Such a difference is not merely stylistic: It allowed the top pulley of the Grand-Prix to run as close to the smallest cog as it did to the largest, or any in between. Shifting thus became easier and more precise, especially on wide-range touring gears. People were amazed at the difference when they replaced their malfunctioning or broken Huret Luxes, Campagnolo Gran Turismos or Simplex Prestiges with something from SunTour. I know I was.
Without a way of keeping a constant distance between the derailleur pulley and the rear cogs, it's all but impossible to make any sort of indexed derailleur system work reliably. Ironically, this fact would lead Shimano and Campagnolo (and, later, SRAM) to claim supremacy over the market SunTour would dominate from the mid-1970's until the mid-1980s--and, ultimately, to SunTour's demise.
Practically the second SunTour's patent expired in 1984, Campy and Shimano (and Sachs-Huret, which would become part of SRAM) seized upon it. The following year, Shimano introduced SIS, the first commercially successful indexed derailleur shifting system. The rear derailleur from that system combined SunTour's slant parallelogram with the spring-loaded top pivot Shimano (as well as Simplex) had already been using in their derailleurs.
Notice that I said SIS was the first commercially-successful indexed derailleur system. It wasn't the first indexed system: The idea was tried as far back as the 1930's (the "Funiculo" derailleur on Jacques Schulz bicycles), and in 1969 SunTour introduced an indexed system that, by all accounts, worked well.
Had SunTour waited a couple more years to market that system, they might have dominated the bicycle components industry even more they did in the 1970s, and they still might be in business today. However, the "Honor" and GT derailleurs-- refinements of the Grand-Prix--and the "V" series were introduced just as the '70's Bike Boom was starting in North America. New cyclists (like yours truly) in the New World had no previous brand loyalty, if you will, to any of the established European derailleur makers and were more willing to try something that looked (and, more important, worked) differently.
Interestingly, this led to a reversal of an old dynamic: A few years later, European cyclists (some, anyway) would take the lead of their American counterparts and start using SunTour (and, later, Shimano) derailleurs and other parts.
Anyway...After Shimano introduced their indexed system in 1985, other companies--including SunTour and Campagnolo-- panicked and introduced their own systems. Some of us referred to Campy's "Syncros" system as "Stinkros". SunTour's system shifted a little better, but not as well as Shimano's, which consisted of a more closely-integrated set of components. Essentially, Shimano designed a whole new system, while SunTour and Campagnolo simply created new indexed shift levers that were supposed to work with derailleurs and freewheels those companies were already making.
What made matters worse was that bike manufacturers, like Schwinn, equipped some of their models with SunTour's indexed shifters but used them with freewheels, chains and cables--some of which weren't even made by SunTour--they already had on hand. It almost goes without saying that the results ranged from underwhelming to disastrous.
(Also, the fact that Schwinn's reputation was already slipping didn't help to bolster confidence in the components they used on their bikes. That's my opinion, anyway.)
SunTour finally redesigned their indexed systems, but it was too late. The company managed to hang on until 1995. By then, nearly all bikes of any quality had Shimano derailleurs--which had the same geometry as the SunTour derailleurs Nobuo Ozaki created three decades earlier!
(He was, apparently, much better at industrial design and engineering than anyone in the company was at translating. One of their early manuals, useful as it is, tells us "How To Use Honor Rightly".)
Some would say, well, duh, it's the invention of the bicycle. I might agree, except that it's hard to pinpoint when, exactly, the bicycle was "invented". Is Leonardo da Vinci responsible for it? Or, do you consider the "celerifere" the first in the line of two-wheeled vehicles we love to ride to day? Some might say Karl von Drais de Sauerbrun, who attached a steering device to his two-wheeler, is the progenitor of our pleasures. Then again, others would have us believe that it wasn't really a bicycle until Kirkpatrick MacMillan attached foot pedals to it.
After the invention of the bicycle, however you define it, probably the most important development--and certainly the one most influential beyond the world of cycling--is that of the pneumatic tire. Without it, not only bicycles, but also motor vehicles, would give slower and bumpier rides than wooden- or metal-wheeled horse-drawn carriages. And modern passenger aircraft could not take off or land.
Possibly the next-most important development is the invention of the "safety" bicycle. It's what we (well, most of us, anyway) ride today: two wheels the same size (or close to it), foot pedals and a front chain that drives a rear cog via a chain. This type of bicycle replaced the high-wheeler or "penny farthing" bikes, on which the pedals and cranks were attached to the front wheel axle. The gear ratio was, therefore, dependent on the size of the front wheel: Common diameters were 60 and 72 inches. On the "safety" bicycle, variable gears were possible.
Variable gears led to inventors coming up with various ways to use them, the most common of which are variable-gear internal hubs (e.g., the Sturmey-Archer three-speed hubs found on classic English bikes) and derailleurs.
About the latter: The patent for what is, arguably, the most important innovation in derailleur design was filed fifty years ago this month in Japan, and a month later in the US.
Here we can see it advertised in the December 1964 edition of New Cycling magazine:
It's the SunTour Gran-Prix derailleur, the progenitor of every single derailleur with even the slightest pretense of quality made during the past few decades.
This brainchild of Nobuo Ozaki, SunTour's chief engineer at the time, the SunTour Gran-Prix introduced the "slant parallelogram" design to the world. The derailleur's main parallelogram is more or less parallel to the chainstay, in contrast to those of Campagnolo and Simplex derailleurs, which dropped straight down from the frame mount and were almost perpendicular to the ground--or those of Huret derailleurs, which consisted of flat steel plates that pivoted on the mounting plate.
Such a difference is not merely stylistic: It allowed the top pulley of the Grand-Prix to run as close to the smallest cog as it did to the largest, or any in between. Shifting thus became easier and more precise, especially on wide-range touring gears. People were amazed at the difference when they replaced their malfunctioning or broken Huret Luxes, Campagnolo Gran Turismos or Simplex Prestiges with something from SunTour. I know I was.
Without a way of keeping a constant distance between the derailleur pulley and the rear cogs, it's all but impossible to make any sort of indexed derailleur system work reliably. Ironically, this fact would lead Shimano and Campagnolo (and, later, SRAM) to claim supremacy over the market SunTour would dominate from the mid-1970's until the mid-1980s--and, ultimately, to SunTour's demise.
Practically the second SunTour's patent expired in 1984, Campy and Shimano (and Sachs-Huret, which would become part of SRAM) seized upon it. The following year, Shimano introduced SIS, the first commercially successful indexed derailleur shifting system. The rear derailleur from that system combined SunTour's slant parallelogram with the spring-loaded top pivot Shimano (as well as Simplex) had already been using in their derailleurs.
Notice that I said SIS was the first commercially-successful indexed derailleur system. It wasn't the first indexed system: The idea was tried as far back as the 1930's (the "Funiculo" derailleur on Jacques Schulz bicycles), and in 1969 SunTour introduced an indexed system that, by all accounts, worked well.
Had SunTour waited a couple more years to market that system, they might have dominated the bicycle components industry even more they did in the 1970s, and they still might be in business today. However, the "Honor" and GT derailleurs-- refinements of the Grand-Prix--and the "V" series were introduced just as the '70's Bike Boom was starting in North America. New cyclists (like yours truly) in the New World had no previous brand loyalty, if you will, to any of the established European derailleur makers and were more willing to try something that looked (and, more important, worked) differently.
Interestingly, this led to a reversal of an old dynamic: A few years later, European cyclists (some, anyway) would take the lead of their American counterparts and start using SunTour (and, later, Shimano) derailleurs and other parts.
Anyway...After Shimano introduced their indexed system in 1985, other companies--including SunTour and Campagnolo-- panicked and introduced their own systems. Some of us referred to Campy's "Syncros" system as "Stinkros". SunTour's system shifted a little better, but not as well as Shimano's, which consisted of a more closely-integrated set of components. Essentially, Shimano designed a whole new system, while SunTour and Campagnolo simply created new indexed shift levers that were supposed to work with derailleurs and freewheels those companies were already making.
What made matters worse was that bike manufacturers, like Schwinn, equipped some of their models with SunTour's indexed shifters but used them with freewheels, chains and cables--some of which weren't even made by SunTour--they already had on hand. It almost goes without saying that the results ranged from underwhelming to disastrous.
(Also, the fact that Schwinn's reputation was already slipping didn't help to bolster confidence in the components they used on their bikes. That's my opinion, anyway.)
SunTour finally redesigned their indexed systems, but it was too late. The company managed to hang on until 1995. By then, nearly all bikes of any quality had Shimano derailleurs--which had the same geometry as the SunTour derailleurs Nobuo Ozaki created three decades earlier!
(He was, apparently, much better at industrial design and engineering than anyone in the company was at translating. One of their early manuals, useful as it is, tells us "How To Use Honor Rightly".)