Can someone explain the paradox of gears ?!
bristolpete
Posts: 2,255
As per the title, can anyone explain what gain, development etc is when it comes to gearing.
Looking at two set ups on with compact 50/34 on the front and 12/23 on the rear.
The other is 53/39 with 14/25 on the rear.
Common sense tells me that the back gains two teeth in the rear and 3 on the front so I would assume a one tooth difference. Yet, when you out this equations into a gear calculator, the differences in speed from 50 to 53 across the block are marginal to say the least. I cite the 12/23 on the rear for nice tight ratios and the 14/25 on the 53/39 as when running 53, I rarely use 11/12/13 unless hooning down a descent.
The reason I use the word paradox is that in simple terms, I always thought a bigger ring on the front coupled with a nice tight cassette would be faster, but with all things being equal, cadence, crank length etc there is not a lot to choose between them.....and it is not simply counting one up or down on either the front or the back.
Any pointers or thoughts?
Looking at two set ups on with compact 50/34 on the front and 12/23 on the rear.
The other is 53/39 with 14/25 on the rear.
Common sense tells me that the back gains two teeth in the rear and 3 on the front so I would assume a one tooth difference. Yet, when you out this equations into a gear calculator, the differences in speed from 50 to 53 across the block are marginal to say the least. I cite the 12/23 on the rear for nice tight ratios and the 14/25 on the 53/39 as when running 53, I rarely use 11/12/13 unless hooning down a descent.
The reason I use the word paradox is that in simple terms, I always thought a bigger ring on the front coupled with a nice tight cassette would be faster, but with all things being equal, cadence, crank length etc there is not a lot to choose between them.....and it is not simply counting one up or down on either the front or the back.
Any pointers or thoughts?
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Comments
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23->25 on the cassette is a larger proportional gain than 50->53 on the chain rings. The absolute number of teeth is irrelevant, it's the ratio between the number of teeth on the rings and cassette that matters.0
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slowondefy2 wrote:Wa-huh? Brain vomit much?
23->25 on the cassette is a larger proportional gain than 50->53 on the chain rings. The absolute number of teeth is irrelevant, it's the ratio between the number of teeth on hte rings and cassette that matters.
Exactly :? So I think I am looking for smaller ratios then yeah when choosing a new set up as I like riding 52/39 with a 14/25 on the rear, which I feel gives me the gearing I require. Not a climber and my choice makes that harder, but I tend to focus and ride in a way where I use the big ring more. I get up cheddar 39/25, but looking at a compact for a different bike for the upward slopes. The whole thing has puzzled me as I simply just thought bigger = faster which aint the case.0 -
my bike - faster than god's and twice as shiny0
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well bigger(on the front) does equal faster providing you keep the same cassette on(and can push dem pedals fast enough) otherwise youre not comparing like for likeDeath or Glory- Just another Story0
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bristolpete wrote:As per the title, can anyone explain what gain, development etc is when it comes to gearing.
Looking at two set ups on with compact 50/34 on the front and 12/23 on the rear.
The other is 53/39 with 14/25 on the rear.
Common sense tells me that the back gains two teeth in the rear and 3 on the front so I would assume a one tooth difference. Yet, when you out this equations into a gear calculator, the differences in speed from 50 to 53 across the block are marginal to say the least. I cite the 12/23 on the rear for nice tight ratios and the 14/25 on the 53/39 as when running 53, I rarely use 11/12/13 unless hooning down a descent.
The reason I use the word paradox is that in simple terms, I always thought a bigger ring on the front coupled with a nice tight cassette would be faster, but with all things being equal, cadence, crank length etc there is not a lot to choose between them.....and it is not simply counting one up or down on either the front or the back.
Any pointers or thoughts?
What you've done here is fail at maths, and use addition when you need to use multiplication. 50 to 53 is a 6% increase in gearing, 13 to 14 is a 7.2% decrease. Add 1 to both and multiply, and you'll discover that theres less than 2% difference between the two, and in fact the 50/13 is the bigger gear.
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cosmic microwave background
aicmfpmy bike - faster than god's and twice as shiny0 -
Have a look at this
http://home.earthlink.net/~mike.sherman/shift.html0
