Gain Ratio!?

Gain ratio is a standard for measuring how high or low a gearing is. Sheldon "Quixote" Brown developed this measuring system to account for all the different possible chain ring, wheel, gear, and crank sizes.

"This ratio would be calculated as follows: divide the wheel radius by the crank length; this will yield a single radius ratio applicable to all of the gears of a given bike. The individual gear ratios are calculated as with gear inches, using this radius ratio instead of the wheel size." from http://www.sheldonbrown.com/gain.html

There is also a calculator for gain rations here: http://www.sheldonbrown.com/gears/

Pluggin in the sizes of our bikes yeilds:
- Pattt
700 x 28 (wheel size)
165 mm cranks
48 tooth chain ring
16 tooth cog
yields a gain ratio of 6.2.

- Jesse
700 x 28 (wheel size)
165 mm cranks
48 tooth chain ring
16 tooth cog
yields a gain ratio of 6.2.

- Adam
700 x 28 (wheel size)
165 mm cranks
48 tooth chain ring
17 tooth cog
yields a gain ratio of 5.9.

One of our goals in this trip is to never change our gearing. We brought some spare 17 and 18 tooth cogs but we won't be using them unless it is absolutely necessary! We made it up Santiam Pass with no problem... Hopefully we will be able to do the same with the remaining mountains :)

-Pattt