What cadence is
Cadence is how fast you turn the pedals, counted in revolutions per minute, often shortened to rpm. One full turn of the cranks is one revolution. If you complete one turn every second, your cadence is 60 rpm.
Cadence is separate from speed. You can pedal slowly in a hard gear or quickly in an easy gear and travel at the same speed. That is why cadence is useful: it tells you something speed cannot, namely how you are getting that speed.
How a cadence sensor works
A cadence sensor detects each turn of the crank. Some use a small magnet fixed to a crank arm and a sensor on the frame that notices it passing. Others are self-contained units that sense motion and attach to a crank or shoe. In both cases the sensor counts turns over time and sends the result to your computer wirelessly.
Most computers pair with sensors through common wireless standards, and the manufacturer’s guide will say which ones. The general process is similar across brands:
- Switch on the sensor, which may need a few pedal turns to wake it.
- Put the computer into its sensor search or pairing mode.
- Select the sensor when it appears and confirm it shows a number.
- Turn the cranks and check the reading moves sensibly.
If the sensor drops out or shows odd readings, a loose mounting or a weak battery is a common cause. Follow the product’s instructions for fitting and replacing batteries, and see a bike shop if the sensor mounting is awkward on your frame.
Why beginners often mash
Many new riders stay in a gear that feels hard and push slowly, which is sometimes called mashing. It can feel natural because it feels strong. But it asks a lot of your legs and knees for every pedal stroke, and it tends to tire you earlier than a lighter, quicker rhythm would.
A cadence number makes this visible. If it is very low and your legs feel heavy, an easier gear is usually worth trying. The article on using bike gears covers how the gears work.
Finding a comfortable range
There is no single correct cadence. Comfortable cadence depends on your fitness, the terrain, your bike and your body, and different people settle in different places. Many casual riders find a moderate, fairly quick spin comfortable on flat ground, and experienced riders often keep a similar spin on climbs by changing gears.
A simple way to learn your own range:
- Ride a flat, quiet stretch at an easy effort.
- Shift up and down a few gears and watch how the number changes.
- Notice where your pedalling feels smooth, relaxed and unforced, with no bouncing in the saddle.
- Note the number in that spot and use it as a rough starting point.
If you ever feel knee pain or other discomfort, ease off and consider talking to a doctor or a qualified bike fitter, since a saddle or cleat position problem can be involved. The article on professional bike fit explains when that is worth doing.
Using cadence to choose gears
Once you know your comfortable range, the sensor becomes a quick check for gear choice.
- Cadence dropping on a rise: shift to an easier gear before you slow right down. The article on shifting before climbs explains the timing.
- Cadence very high and legs spinning without much speed, such as on a fast descent: shift to a harder gear, or simply coast if it is safe to do so.
- Starting from a stop: pick an easy gear, so your cadence rises quickly and you stay balanced.
Shift smoothly and ease the pressure on the pedals for a moment as you change gear. Smooth shifting protects the drivetrain and keeps your rhythm even.
Pedalling smoothly
Cadence tells you speed of turning, not quality. To improve smoothness:
- Think about turning circles rather than stamping down.
- Keep your upper body relaxed and your hands light on the bars.
- Avoid bouncing in the saddle at higher cadences. If you bounce, ease the cadence a little or work on relaxing your hips.
The article on the pedal stroke goes into the movement in more detail, so this one keeps to the sensor and the number.
Keeping it in perspective
Do not stare at the cadence field. A quick glance on a straight, quiet stretch is plenty, and in traffic or on rough ground your eyes belong on the road. If a number makes you tense or overthink, hide it for a few rides and go by feel. The aim is not to hit a number but to ride in a way that feels easy to sustain.
Cadence is also only one measure. It is more useful alongside how you feel, the terrain and the wind than as a target on its own.