Short answer
For climbing, choose an easier (lower) gear: the smaller chainring at the front and a larger cog at the back. Each pedal turn then moves the bike less, so you can keep a steady, comfortable effort rather than grinding. If you need a diagram of which is which, see bike gears explained with a diagram.
Shift before the hill
Shift early. Changing gear while pushing hard on the pedals is rough on the drivetrain and can make the chain skip or jam. As the road starts to rise, move down a gear or two, and ease off the pedal pressure for a moment as the chain moves. If you wait until you are almost stopped, shifting can be difficult.
Front and rear on a climb
On a bike with two or three chainrings:
- Front shifter (usually left): moves the chain between chainrings. Use the small ring for steep or long climbs.
- Rear shifter (usually right): makes smaller steps across the cassette. Move towards larger cogs as the slope increases.
A common approach is to use the rear shifter for fine changes, and drop to the small chainring when the rear gears alone are not enough. On a single-chainring bike, only the rear shifter is needed.
Technique tips
- Aim for a pedal speed that feels smooth rather than heavy. Many riders find a higher, lighter pedal rhythm sustainable for longer than pushing hard on the pedals.
- Anticipate changes in slope and shift one step at a time.
- Avoid the extremes of the cassette combined with the wrong chainring (cross-chaining), such as the large chainring with the largest cog.
- Staying seated and relaxed may save energy on long climbs, while standing can help briefly on a steep pitch.
Going downhill
Reverse the thinking. As speed increases, shift to harder gears (a larger chainring or smaller cog) so your legs are not spinning too fast to be useful. You can also coast.
If your lowest gear is still too hard
- Check that your shifting is working and the chain reaches the biggest cog. If it does not, see why bike gears keep slipping.
- A cassette with a larger biggest cog may give easier gears, if your rear derailleur supports it. Check the manufacturer’s capacity limits.
- A smaller front chainring (for example, a compact crankset) can also lower the gearing.
- On a single-speed bike, a larger rear cog or smaller chainring makes the bike easier on hills, or you could consider adding gears to a single speed bike.
52/36 versus 50/34, and 21 versus 7 speed
A 50/34 crankset has an easier lowest gear than a 52/36, which many people prefer for climbing, while a 52/36 gives a taller top gear. Neither is universally better, and the cassette matters too; see how many gears a road bike has. A 21-speed bike generally has a wider range than a 7-speed single-chainring bike, which can help on steep hills, though the 7-speed is simpler. For the vocabulary behind these setups, read bike gear names.