Legacies and rationality
04/06/08 07:54 Filed in: Cycling
Recently a friend had finally acquired a bicycle that
he wanted - it was a hybrid with flat bars rather
than drops, had skinny wheels rather than MTB tyres.
But my friend had found the two shifters to be
inconsistent - he wanted them both to move the same
way with similar effects. We talked for a little
while about shifting - he used the numbers on his
shifters - which didn't mean a lot to me as a) my
shifters don't have any numbers b) I've used
thumbshifters, grip shifters and only in the past 8
years rapidfire shifters c) I've been using them for
so long that it's largely autonomous. So I wasn't
really able to comment on the numbers part - must be
a car driver's thing - and the expectation that the
gear will be engaged when the number is indicated.
There is of course a huge difference between a car gearbox where there is a very on/off gear engagement - either you have got it in the gear selected or you can clearly hear that you haven't. Whereas with bike gears it is pulling a cable to move a deraillieur to move the chain across from one gear ring to another. There's a lot more variability in that.
Anyway, back to the rational movement discussion - that is he wanted when he moved the right hand shifter up or the left hand shifter up they should do the same result - eg selected a lower gear. The difficulty is the difference in the physical nature of the two parts of the gear systems: the front chain rings have the largest on the outside and the smallest on the inside; whereas the rear cassette has the opposite - largest on the inside and smallest on the outside. Of course, there is also the difference between the front - a larger ring is a higher gear, and the back - a smaller ring is a higher gear.
So what would we do? Chain the rings around? Change the rear cassette? Add more complications to the shifters? Or leave it as it's always been?
Your guess.....
This discussion made me also say that there are things that have developed because someone thought of something and did it that way (just because) and it has become the de facto way of doing that. Now it's too late to alter it. I'm sure you can think of your own examples.
There is of course a huge difference between a car gearbox where there is a very on/off gear engagement - either you have got it in the gear selected or you can clearly hear that you haven't. Whereas with bike gears it is pulling a cable to move a deraillieur to move the chain across from one gear ring to another. There's a lot more variability in that.
Anyway, back to the rational movement discussion - that is he wanted when he moved the right hand shifter up or the left hand shifter up they should do the same result - eg selected a lower gear. The difficulty is the difference in the physical nature of the two parts of the gear systems: the front chain rings have the largest on the outside and the smallest on the inside; whereas the rear cassette has the opposite - largest on the inside and smallest on the outside. Of course, there is also the difference between the front - a larger ring is a higher gear, and the back - a smaller ring is a higher gear.
So what would we do? Chain the rings around? Change the rear cassette? Add more complications to the shifters? Or leave it as it's always been?
Your guess.....
This discussion made me also say that there are things that have developed because someone thought of something and did it that way (just because) and it has become the de facto way of doing that. Now it's too late to alter it. I'm sure you can think of your own examples.
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