I forget who told me that there's no idea so bad that nobody will try to revive it.
Here's a case in point: low-normal rear, and top-normal front, derailleurs.
On the bikes most of you ride, pushing the right lever forward shifts you to a higher rear gear (top-normal), and pulling the lever brings you to a lower gear. Conversely, pulling on the left lever shifts your chain to the larger front sprocket, and pushing it drops your chain to the smaller, or lower gear (low-normal). The derailleurs I'm going to talk about do the exact opposite.
It seems that every generation or so, someone tries to revive the idea. Why, I don't know.
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This is an early example of the genre: the Simplex Champion de France, circa 1935. Believe it or not, it was a technological marvel for its time, even though it couldn't handle much more than a 22 tooth rear cog and a difference of 8 between the largest and smallest cog.
It is, I think, rather elegant: In particular, the cage shape makes me think of a part of a piano rather than a bicycle. However, the shifts of single-pulley derailleurs are inherently imprecise; low-normal operation only exacerbates the problem.
As one might expect, World War II halted derailleur development and all but stopped their manufacture altogether. The 1950's would see new innovations and experiments, including the pull-chain mechanism (which Shimano briefly revived on its mountain bike derailleurs during the late 1990's) and, most important, a derailleur with a parallelogram mechanism rather than a single arm or cam. However, Simplex and other companies also revived low-normal rear derailleurs.
To be fair, the first modern rear derailleur (and, some would say, the first that shifted well)--the Sun Tour Gran Prix of 1964--also was low-normal. But within two years, Sun Tour abandoned that operating principle, realizing that the slant-parallelogram design (which is found on every derailleur of any quality made in the last quarter-century or so) did more to improve shifting than any other idea or innovation.
However, Sun Tour continued to make front derailleurs that were "top normal" well into the 1970's. I had one such derailleur. It shifted well enough until the spring started to lose its tension. With a low-normal front derailleur, you can sometimes adjust the cable tension to make up for the lack of spring tension. That's not an option with high-normal front derailleurs.
It's also not an option with low-normal rear derailluers. I briefly rode one on my mountain bike about fifteen years ago: a Shimano XTR. Luckily for me, the shop from which I bought it allowed me to trade it in for a more conventional XT rear. The owner of the shop reasoned that the amount of wear I put on the XTR made it depreciate enough to warrant an XT as a replacement.
I'd say that was an example of addition by subtraction: I was happy with the XT, as I was with an earlier version of the same derailleur. On the other hand, I never liked the low-normal XTR, which was one of the most expensive derailleurs made at the time. It never had the firm, postive feel I like when shifting: Even when the gear engaged smoothly and silently after a shift, it always felt as if the chain would slip or jump off the gear at any moment.
Other cyclists with whom I rode--who included hard-core mountain bikers as well as roadies like me who went off-road for a change of pace--felt the same way about that derailleur. And, in looking back at some old magazines and books, it seems that every time low-normal derailleurs come out, the high-mileage and hard-driving riders don't like them. Even less-experienced riders who thought they were the newest and latest thing soon soured on them.
I see that Shimano has given up on low-normal (or, in their lingo, "rapid rise") rear derailleurs, at least for now. I wonder whether they, or any other company, will revive them. Maybe they will in a decade or so, when there's a cohort of cyclists who didn't use rapid-rise and who don't heed this gem of wisdom from Ecclesiastes: There is nothing new under the sun.
Here's a case in point: low-normal rear, and top-normal front, derailleurs.
On the bikes most of you ride, pushing the right lever forward shifts you to a higher rear gear (top-normal), and pulling the lever brings you to a lower gear. Conversely, pulling on the left lever shifts your chain to the larger front sprocket, and pushing it drops your chain to the smaller, or lower gear (low-normal). The derailleurs I'm going to talk about do the exact opposite.
It seems that every generation or so, someone tries to revive the idea. Why, I don't know.
-filtered.jpg)
This is an early example of the genre: the Simplex Champion de France, circa 1935. Believe it or not, it was a technological marvel for its time, even though it couldn't handle much more than a 22 tooth rear cog and a difference of 8 between the largest and smallest cog.
It is, I think, rather elegant: In particular, the cage shape makes me think of a part of a piano rather than a bicycle. However, the shifts of single-pulley derailleurs are inherently imprecise; low-normal operation only exacerbates the problem.
As one might expect, World War II halted derailleur development and all but stopped their manufacture altogether. The 1950's would see new innovations and experiments, including the pull-chain mechanism (which Shimano briefly revived on its mountain bike derailleurs during the late 1990's) and, most important, a derailleur with a parallelogram mechanism rather than a single arm or cam. However, Simplex and other companies also revived low-normal rear derailleurs.
To be fair, the first modern rear derailleur (and, some would say, the first that shifted well)--the Sun Tour Gran Prix of 1964--also was low-normal. But within two years, Sun Tour abandoned that operating principle, realizing that the slant-parallelogram design (which is found on every derailleur of any quality made in the last quarter-century or so) did more to improve shifting than any other idea or innovation.
However, Sun Tour continued to make front derailleurs that were "top normal" well into the 1970's. I had one such derailleur. It shifted well enough until the spring started to lose its tension. With a low-normal front derailleur, you can sometimes adjust the cable tension to make up for the lack of spring tension. That's not an option with high-normal front derailleurs.
It's also not an option with low-normal rear derailluers. I briefly rode one on my mountain bike about fifteen years ago: a Shimano XTR. Luckily for me, the shop from which I bought it allowed me to trade it in for a more conventional XT rear. The owner of the shop reasoned that the amount of wear I put on the XTR made it depreciate enough to warrant an XT as a replacement.
I'd say that was an example of addition by subtraction: I was happy with the XT, as I was with an earlier version of the same derailleur. On the other hand, I never liked the low-normal XTR, which was one of the most expensive derailleurs made at the time. It never had the firm, postive feel I like when shifting: Even when the gear engaged smoothly and silently after a shift, it always felt as if the chain would slip or jump off the gear at any moment.
Other cyclists with whom I rode--who included hard-core mountain bikers as well as roadies like me who went off-road for a change of pace--felt the same way about that derailleur. And, in looking back at some old magazines and books, it seems that every time low-normal derailleurs come out, the high-mileage and hard-driving riders don't like them. Even less-experienced riders who thought they were the newest and latest thing soon soured on them.
I see that Shimano has given up on low-normal (or, in their lingo, "rapid rise") rear derailleurs, at least for now. I wonder whether they, or any other company, will revive them. Maybe they will in a decade or so, when there's a cohort of cyclists who didn't use rapid-rise and who don't heed this gem of wisdom from Ecclesiastes: There is nothing new under the sun.
