How Much Energy Does Drafting Save on a Bicycle?
Drafting 0.1–0.5m behind another cyclist saves about 27–50% of your aerodynamic power. Buried mid-pack in a large group, drag can drop to just 5–10% of riding solo — at cruising speeds that's tens to over a hundred watts of free energy. The savings decay fast with distance; here's the full curve.
The numbers from research
- Closely behind a single rider (0.1–0.5m wheel gap): about 27–50% aero power savings — consistent from the classic wind-tunnel and field studies (Kyle, 1979) to modern CFD.
- Mid-pack in a large group: Blocken et al.’s 2018 CFD study of a 121-rider peloton found riders buried in the belly of the bunch experience as little as 5–10% of solo drag.
- The leader gains a little too: the follower fills in the leader’s low-pressure wake, cutting the front rider’s drag by ~2–3%.
Distance decay: every half wheel leaks watts
Benefits fall off quickly with gap: 0.1–0.3m is maximal; at one bike length (~2m) savings often drop to ~20%; beyond 3–4 bike lengths there is little left. In crosswinds the wake shifts sideways — which is why echelons form diagonally.
Drag the gap slider and watch the savings decay
Open draft mode in our free browser wind tunnel: drag the spacing slider and watch the rear rider’s drag percentage and watts saved change in real time, with the low-pressure wake drawn for you.
Open VeloTunnel draft mode ›Does drafting still help on climbs — and by group position?
Yes, though the benefit scales with speed. Aerodynamic drag grows with the cube of velocity, so the draft is worth the most where you are fastest:
| Situation | Typical speed | Power saved in the draft |
|---|---|---|
| Flat road, 2nd wheel | 35–40 km/h | ~27–35% |
| Flat road, 3rd–4th wheel | 35–40 km/h | ~40–50% |
| Mid-pack in a big group | 40+ km/h | drag falls to 5–10% of solo |
| Climb at 7.5% gradient | ~20 km/h | still >7% of required power |
| Fast descent | 60+ km/h | largest absolute watt savings — but keep bigger gaps for braking |
Two practical takeaways: on climbs the draft never drops to zero, so hold the wheel on gradual gradients; and the deeper you sit in a group, the more the savings compound — 3rd wheel is measurably cheaper than 2nd.
Safety rules
- Never overlap the wheel in front — the number-one cause of group crashes.
- Look through the rider ahead, over their shoulder at the road, not at their wheel.
- Feather the brakes: speed control in the draft is anticipation plus light touches, never grabs.
- Rotate: in a group of 2–4, pull for 30s–2min each; a rotating paceline cruises 3–5 km/h faster than any solo rider.
Want to sit lower and steadier in the draft? Make sure your setup allows it — see aerodynamics & CdA explained.
A stable draft position starts with a correct fit
Upload a side-view riding video — AI measures your knee/hip/torso angles and tells you how much lower you can sustainably go.
Upload a video, start the analysis ›FAQ
How much power does drafting save?
Studies show riding 0.1–0.5m behind another cyclist saves roughly 27–50% of aerodynamic power; buried mid-pack in a big group, drag can fall to 5–10% of riding solo — tens to over a hundred watts at cruising speeds.
How close do I need to follow for real benefit?
Closer is better: 0.1–0.3m gives the maximum benefit, savings drop to around 20% at one bike length (~2m), and little remains beyond 3–4 bike lengths. Beginners should start around 0.5m and close the gap as skills improve.
Does drafting help on climbs?
Yes — less than on the flat, but never zero. Even at a 7.5% gradient around 20 km/h, drafting saves over 7% of required power, and the benefit grows back as the road flattens or the speed rises. On fast descents the absolute watt savings are the largest of all.
Does the lead rider work harder because of a drafter?
No — slightly the opposite. The follower fills the leader’s low-pressure wake, reducing the front rider’s drag by about 2–3%. Pulling is still by far the hardest position, which is why groups rotate.
Related guides
- Cycling aerodynamics & CdA explained — where the other 70% of your power actually goes
- What wind tunnel testing costs — and the free browser alternative
- TT & aero torso angle — how low can you sustainably go