basic road bike shifting

The Excellent Wife (TEW) has asked for an explanation of shifting on her new road bike. The idea that sometimes when the chain is on a smaller gear pedaling is easier, while other times it's harder, has her completely consternated (one of her favorite words). So here's a brief explanation.

The left control works the gears at the pedals, usually called the chainrings. The assembly is referred to as the crank.

The right control works the gears at the rear wheel, usually called the cogs or the cassette.

On either control, on your Shimano setup, pushing in both levers moves the chain to a LARGER gear. Pushing just the rear, shorter lever allows the chain to snap to a SMALLER gear.

Here's where it gets confusing: On the crank, moving the chain to the larger, outside gear makes pedaling harder, although you go farther with each pedal revolution.The smaller, inside gear is easier to pedal, and you don't go as far.

At the cassette, moving the chain to the larger, inside gear (purists will call it a cog, but it's round and toothy, so it will do as a gear) makes pedaling easier, and you don't go as far. The smaller, outside gears make you go farther, but they make pedaling harder - sometimes MUCH harder.

Using the size of the gears to determine whether you will go faster or slower will lead you to confusion, because the action will be different depending on whether the gear is at the crank or the rear wheel.

The one thing the IS a constant is how far the chain is from the frame of the bike. As the chain is moved closer to the bike, either at the crank, the rear wheel, or both, pedaling becomes easier. As the chain is moved away, pedaling becomes harder.

I generally use the front gears for "macro" changes and the rear gears for "micro" changes - for example, if I'm on a hilly part of a ride, I might leave the chain on the smaller chainring, and do most of the shifting on the back as the road requires (until I come to a long downhill). On flats, I generally leave the chain on the larger front gear (or chainring).

Hope this is helpful.