Steepness, gears, cadence, power and such

The recent post A bit about gearing got me thinking.

Given a certain steepness, a desired cadence and the ability to rock a given amount of power, what should your low gear be?

Method
I did a little basic math and plugged it into this Excel calculator. It’s not as rad as I want it to be, but it’ll do for now.

If you’re a nerd, you must download this. Numbers are FUN!

Assumptions
– Road bike with 34t small ring.

– Bike and rider weigh 200 pounds.

– Grade is 10 percent.

– Pedaling cadence is 60 rpm. Not as spinny as the “ideal” 80 rpm, but still pretty good on an extended remix death march.

– No headwind.

– Looking for fun and feeling groovy.

Results
34t x 28t gear – Rider must sustain 284 watts.

34t x 36t gear – Rider must sustain 215 watts.

What this means
An easier gear requires less power to turn up a steep hill. Duh.

The 34×28 is good for an averagely gifted but decently fit rider. As a matter of fact, my Tricross and I weigh 200 pounds, I run a 34×28, I climb lots of 10 percent grades and I can currently sustain about 280 watts. It’s funny how the math works out.

Last winter before I did my 12-week indoor trainer death interval program, I could only sustain about 220 watts. That 34×36 would have been nice, but I’m glad I trained hard and got stronger.

The moral of this hasty tale: Choosing your low gear has nothing to do with cool factor. How much do you weigh? How steep are your hills? How fast do you want to spin? How much power can you make? Are you looking for fun? Are you feeling groovy?

Download this chick-impressing Excel calculator and run some numbers for yourself.

Braaap!

— Lee

Know more. Have more fun!

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