Knee Pain on the Bike — Causes and How to Avoid It
The knee is the most heavily loaded joint on a bike — it does thousands of repetitions an hour within a limited range of motion. Knee pain is a signal that something about your bike fit, technique or load is off. The good news: in most cases, correcting your position, cadence or load progression is enough to make the problem disappear. Here's where to look for the cause.
Pain at the front of the knee (anterior)
The most common type — pain around the kneecap or patellar tendon. Typical causes:
- Saddle too low — the knee works through too closed an angle, overloading the joint,
- Saddle too far forward — the knee sits ahead of the pedal axle, so load runs through the joint instead of the muscles,
- Cadence too low — spinning a heavy gear (50–60 RPM) generates large forces in the knee,
- Load increased too fast — muscles adapt faster than tendons and cartilage.
First steps: raise your saddle by 5–10 mm, move it back slightly, and raise your cadence to 80–90 RPM.
Pain at the back of the knee (posterior)
Less common but just as annoying:
- Saddle too high — the leg over-extends, straining the hamstrings and structures at the back of the knee,
- Saddle too far back — too much reach during pedalling.
Fix: lower the saddle by 5 mm, move it slightly forward.
Pain on the side (medial or lateral)
The knee hurts on the inside or outside. Typical cause:
- Badly positioned SPD cleats — forcing an unnatural foot angle,
- Too little float (cleat range of motion) — the foot can't find its natural position,
- Uncorrected leg-length difference — causes asymmetric loading.
Check your cleat position in your SPD shoes — cleat under the ball of the foot, foot in a natural position.
General prevention rules
| Rule | Why |
|---|---|
| Cadence 80–90 RPM | Lower forces in the knee than grinding at 60 RPM |
| Gradual load progression | Tendons and cartilage adapt more slowly than muscle |
| 10–15 min warm-up | Increases blood flow in the joint before hard effort |
| Off-bike leg strengthening | A strong quadriceps and VMO (vastus medialis) stabilise the kneecap |
| A well-fitted bike | Eliminates 80% of knee-pain causes |
When to see a physiotherapist
- Pain persists for more than 2 weeks despite correcting position and cadence,
- swelling or locking appears in the knee,
- pain gets worse despite reduced load,
- you feel instability (the knee "gives way").
A physiotherapist or orthopaedist will assess whether the problem is biomechanical or needs treatment. In some cases, bike fitting with a fitter who's also a physiotherapist is the optimal solution.
Summary
Knee pain on the bike is almost always a sign of poor fit, too low a cadence or too fast a load increase — not of riding itself. Front pain → saddle too low/too far forward; back pain → too high; side pain → cleats. Raise your cadence, fix your position, increase load gradually. If it doesn't go away — see a physiotherapist, don't ignore it.
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