Author Topic: gear comparison  (Read 2539 times)

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Offline HONDO

gear comparison
« on: November 29, 2006, 05:54:23 pm »
My touring bicycle triple chainring is 52/42/24 with 11/32 (9cassette),700c wheels. My hybrid is 44/32/22 with 11/30 (7cassette),26in. wheels. In theory how do these gearings compare and in what way if they were both used for touring.


Offline RussellSeaton

gear comparison
« Reply #1 on: November 29, 2006, 06:53:13 pm »
A gear chart question.  Since you are on the internet, I presume you have access to a spreadsheet program such as Excel.  Make yourself a gear chart.  Put the chainrings along the top row.  Put the cogs down the left hand side of the spreadsheet.  Thr formula to use is Chainring teeth divided by cassette cog teeth times wheel diameter in inches.  Gives commonly used gear inches.  Multiply by Pi 3.14 and you get the number of inches traveled with one turn of the crankarm.  For the chart, figure 26.5" diameter for 700C wheels.  Maybe 27" if they are fat touring tires.  For 26" mountain bike wheels, figure 26" diameter if fat 2.0 inch knobbies.  Figure about 24.5" diameter if 1.25 inch slicks.

With your two setups, you have roughly the same low gear for both.  Lots more high gears (52 ring) with the 700C.  I doubt these are used much when touring.  Useful for recreational riding.  Lots more low-middle gears (32 ring) with the 26" bike.  I doubt these low-middle gears are used much at any time.  In essence you have a very usable range on both bikes, the 42 ring on the 700C and the 44 ring on the 26" bike.  And a climbing range with the inner ring on both bikes.

An important thing to consider when looking at gears is the shift pattern.  And how closely spaced the gears are in the usable range, 50-90 gear inches.


Offline BrianCM

gear comparison
« Reply #2 on: December 04, 2006, 01:54:52 am »
There is a far better way to do this.  Sheldon Brown has a gear calculator on his website.

http://www.sheldonbrown.com/gears/

Try it, its easy!


Offline RussellSeaton

gear comparison
« Reply #3 on: December 04, 2006, 11:48:42 am »
"There is a far better way to do this.  Sheldon Brown has a gear calculator on his website.

http://www.sheldonbrown.com/gears/

Try it, its easy!"

A far better way than actually understanding what you are doing?  A far better way than actually doing the math yourself?  A far better way than actually thinking about how gearing works and how you shift?  Some might say a far better way to see the country is to watch a movie instead of riding a bike.  Its easy.


Offline miles2go

gear comparison
« Reply #4 on: December 13, 2006, 02:17:15 am »
Many people may argue that there's no real need for bicycling past the school years.

Many people may argue that there's no real need for math past the school years.

 :eg:

« Last Edit: April 28, 2010, 03:17:48 am by miles2go »