question on Bike gear ratios

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2008-10-29 7:21 AM

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Regular
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100
Southern Rhode Island
Subject: question on Bike gear ratios

Using an online bike gear calculator> http://www.sheldonbrown.com/gears/ and using my current bike gear layout 53-39 chainrings and 25-12 cassette:



 

Gear chart using MPH @ 80 RPM

For 700 X 23 / 23-622 tire with 167.5 mm cranks

With 10-speed 12-13-14-15-16-17-19-21-23-25 Cassette

 5335.9 %39
1227.6 20.3
8.3 %
1325.5 18.8
7.7 %
1423.7 17.4
7.1 %
1522.1 16.3
6.7 %
1620.7 15.2
6.3 %
1719.5 14.3
11.8 %
1917.4 12.8
10.5 %
2115.8 11.6
9.5 %
2314.4 10.6
8.7 %
2513.3 9.8

this chart is developed.  If you see using the 53 chainring and the 19 cog developes 17.4 mph at a cadence of 80: But using the 39 chainring and the 14 cog it also developes 17.4 mph at a cadence of 80...

My question is : Does my body perceive this as the same gear? Is my energy output the same using one or the other or is there an advantage of using one gear choice over the other?

In my brain I see it as trying to move the same mass(bike and body)the same speed and cadence it should be the same effort level.

I woulds appreciate any input.

Mark

2008-10-29 8:03 AM
in reply to: #1772690

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Not a Coach
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Media, PA
Subject: RE: question on Bike gear ratios
nfd31 - 2008-10-29 8:21 AM

My question is : Does my body perceive this as the same gear? Is my energy output the same using one or the other or is there an advantage of using one gear choice over the other?

Same thing.  No advantage over one or the other.

2008-10-29 8:06 AM
in reply to: #1772737

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Cycling Guru
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Fulton, MD
Subject: RE: question on Bike gear ratios

Your body requires the same amount of power to turn either combination, it could care less which one you use.

There tend to be a lot of similar ratios in a 20-speed set up (and will be even more pronounced with the new 11-speed that Campy has and others are working on).  The key thing to remember is to be pedaling at a cadence that is comfortable for you and shift gears as needed to attain that cadence.

2008-10-29 8:25 AM
in reply to: #1772690

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Champion
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Tacoma, Washington
Subject: RE: question on Bike gear ratios

There are very finely tuned measurement devices that could measure the slight differences between these two -- in theory the 39/14 would have more resistance because of chain motion (the links have to move more to go around the smaller cog/chainring).

You're body isn't that finely tuned. You won't feel the difference.

2008-10-29 3:45 PM
in reply to: #1772690

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Regular
104
100
Southern Rhode Island
Subject: RE: question on Bike gear ratios

Thanks for the replies,

It is as I thought. Same speed---same effort.

Have a great day!

2008-10-29 4:16 PM
in reply to: #1774088

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Champion
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Butler
Subject: RE: question on Bike gear ratios
nfd31 - 2008-10-29 3:45 PM

Thanks for the replies,

It is as I thought. Same speed---same effort.

Have a great day!

Agreed, however when I am in my small chain ring mentally I feel like I am just spinning and not going anywhere for some reason.  I know it is all mental though.

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