Gear Ratio
Gear ratio is the relationship between the number of teeth on the front chainring and the rear cassette sprocket of a bicycle, determining how many times the rear wheel turns per one pedal revolution.
In detail
A higher gear (larger front chainring, smaller rear sprocket) gives higher speed at the same cadence but requires more force per pedal stroke; a lower gear is easier to pedal, especially on climbs, but gives lower speed at the same cadence. Choosing the right gear allows you to maintain an optimal cadence regardless of the gradient.
How to use it
On long mountain climbs (relevant for bike trips across the Caucasus), shift to a lower gear early, before your cadence drops too low — this makes it easier to hold your rhythm and avoid "stalling" on a steep section.