Which time trial helmet is fastest? Velodrome data from real riders
By Kristoffer Visti Graae, physicist, former professional triathlete and founder of AeroGain. Published 02/11/2026.
The short answer
There is no single fastest time trial helmet. In our velodrome tests on real riders, most popular aero helmets are within about 2 W of each other at 45 km/h, and the fastest helmet changes from rider to rider. The ABUS Timeshifter has the highest median, but it is not clearly ahead of the Met Drone, Uvex Race 8 or Ekoi Pure Aero, and it was slower than the rider's other helmet for about one rider in four. The Sweet Protection Redeemer and both Giro Aeroheads were slower for every rider who tried them.
Key findings
- Most popular TT helmets are within about 2 W of each other on the median, measured at 45 km/h on real riders.
- Helmets are individual: even the helmets at the top were slower for a quarter of the riders who tried them.
- ABUS Timeshifter: +2.3 W median against the rider's other helmet (17 riders), but not clearly separable from the Met Drone, Uvex Race 8 or Ekoi Pure Aero.
- Sweet Protection Redeemer: slower for all 6 riders, median 6.3 W.
- Giro Aerohead and Aerohead II: each slower for all 4 riders who tried it.
- A shoulder shrug or tuck usually moved more watts (median about 5 W) than swapping helmets did.
Why this test is different
Most helmet comparisons you can find online show one rider, or a dummy in a wind tunnel. A helmet that is fastest on one rider can be slower on the next, because it sits between the rider's head, shoulders and back. This article shows the same comparison across many riders, each in their own race position, measured with the same method on the velodrome.
How we tested the helmets
During our aero test sessions at Ballerup Super Arena in Copenhagen, riders often try two or three helmets back to back: the one they race in, plus the ones we have with us. We measure each run on the track with a power meter at race speed and calculate the rider's drag area (CdA) from the power, speed, air density and rolling resistance. Each helmet is compared with the other helmet or helmets the same rider wore in the same session, so the rider, bike, position and conditions stay the same. Every rider counts once, and we report the median across riders as watts saved at 45 km/h. Differences smaller than our measurement noise of 1.2 W at 45 km/h count as no difference.
Results: aero helmet comparison at 45 km/h
Median watts saved against the rider's other helmet
At 45 km/h, same rider, same session. Right of the line: faster. Left: slower.
| Helmet | Riders | Median vs rider's other helmet (W) | Faster for | Slower for |
|---|---|---|---|---|
| ABUS Timeshifter | 17 | +2.3 | 53 % | 24 % |
| Ekoi Pure Aero | 17 | +1.4 | 53 % | 29 % |
| Uvex Race 8 | 31 | +1.2 | 52 % | 23 % |
| Met Drone | 28 | +1.0 | 50 % | 25 % |
| Kask Mistral | 5 | +1.0 | 40 % | 20 % |
| Specialized S-Works TT5 | 27 | -0.1 | 33 % | 30 % |
| Rudy Project Wingdream | 26 | -0.5 | 35 % | 35 % |
| Sweet Protection Redeemer | 6 | -6.3 | 0 % | 100 % |
"Faster for" and "slower for" count riders whose difference was larger than the measurement noise; the rest were within noise. Each helmet was compared with whichever helmets its riders also tried, so the medians are not a ranking on one scale. Helmets tried by fewer than five riders are not in the table.
Tried by fewer riders, but consistent: the original Giro Aerohead (4 riders, median -3.5 W) and the Giro Aerohead II (4 riders, median -2.9 W) were each slower than the rider's other helmet for every rider who tried them. They are different helmets, so we show them separately; four riders each is too few to rank them, but the direction is clear.
Head to head: helmet against helmet
These pairs were ridden by the same riders in the same session.
| Comparison | Riders | Median (W) | Result |
|---|---|---|---|
| Met Drone vs Uvex Race 8 | 16 | +1.4 | Individual: Met faster for 56 %, slower for 38 % |
| S-Works TT5 vs Uvex Race 8 | 13 | -1.3 | Individual: TT5 faster for 31 %, slower for 54 % |
| Rudy Project Wingdream vs S-Works TT5 | 12 | -0.1 | Mostly within noise |
| ABUS Timeshifter vs Rudy Project Wingdream | 11 | +2.8 | Timeshifter faster for 6, slower for 1 |
| Ekoi Pure Aero vs Rudy Project Wingdream | 11 | +1.5 | Ekoi faster for 55 %, slower for 18 % |
| ABUS Timeshifter vs Ekoi Pure Aero | 10 | +0.7 | No clear difference |
| Met Drone vs S-Works TT5 | 10 | +0.4 | Mostly within noise |
What the results mean
Aero helmets are individual
Helmets are individual: share of riders faster, no different or slower
Against the rider's other helmet, at 45 km/h. No difference = within our measurement noise of 1.2 W.
Faster No difference (within noise) Slower
The right-hand columns matter more than the medians. Even the helmets at the top of the table were slower for about a quarter of the riders who tried them, and the S-Works TT5 and the Rudy Project Wingdream split riders almost evenly. Our reading of why: how a helmet performs depends on how you hold your head and how far your shoulders come up. The same helmet can close the gap to the back on one rider and stick out into the air on another.
Uvex Race 8, Met Drone, Ekoi, Kask, S-Works TT5 and Rudy Project are close
On the median these helmets are within about 2 W of each other, and in the head-to-heads the winner changes from rider to rider. For most riders in this group, the right helmet is the one that suits their position, not the one with the boldest claim.
Is the ABUS Timeshifter the fastest aero helmet?
The Timeshifter has the highest median in our data: 2.3 W faster than the rider's other helmet, across 17 riders. That is not a clear win. Most of its tests were against the Rudy Project Wingdream and the Ekoi Pure Aero, and on a common scale it sits level with the Met Drone. Against the Wingdream it was faster for 6 of 11 riders and slower for 1. Against the Ekoi Pure Aero there was no clear difference. We decided to sell the ABUS Timeshifter after seeing these results, but in many of our tests it is not the helmet on top, which is why we keep testing helmets per rider.
Timeshifter narrow or wide visor?
Across 9 riders neither visor was consistently faster: the narrow one won for 4 riders and the wide one for 3. Test both if you can.
Sweet Protection Redeemer and Giro Aerohead
The Sweet Protection Redeemer was slower than the rider's other helmet for all six riders who tried it, by a median of 6.3 W. The original Giro Aerohead and the Aerohead II were each slower for all four riders who tried them. The groups are small, but the direction is the same against several different helmets and across several years.
Limits of this data
This is not a designed helmet shoot-out. Riders tried the helmets they brought or that we had with us, so not every helmet met every other helmet, which makes the medians hard to compare across helmets, and some groups are small. Each rider rode their own position, which is the point: the numbers show what happens on real riders rather than on a dummy. The values are medians of paired differences within a session, never averages across tests. Read them as a strong hint, and test the shortlist on yourself.
How to choose an aero helmet
- Test it in your position if you can. A helmet swap on the velodrome shows your own answer, which is the only one that counts.
- Shortlist from the close group. Uvex Race 8, Met Drone, Ekoi Pure Aero, ABUS Timeshifter and S-Works TT5 are all within a couple of watts on the median.
- Pick the one you can hold your position in. Fit and comfort decide whether you keep your head low for the whole race.
- Work on your shoulders. In our sessions, a shoulder shrug or tuck usually moved more watts than swapping helmets. Read how to hold your aero position longer.
Frequently asked questions
What is the fastest time trial helmet?
None for everyone. Across the riders in our velodrome tests the ABUS Timeshifter has the highest median, but it is not clearly ahead of the Met Drone, Uvex Race 8 or Ekoi Pure Aero, and for about a quarter of riders it was slower than their other helmet.
How much faster is an aero helmet?
Between the popular TT helmets in our tests, the differences were small: about 2 W at 45 km/h on the median. The slowest helmets we tested cost 3 to 6 W against the rider's alternative.
Is the Met Drone faster than the Uvex Race 8?
It depends on the rider. Across 16 riders who tried both, the Met Drone was 1.4 W faster on the median, but it was slower than the Uvex for 38 % of them.
Is a more expensive helmet faster?
We did not compare prices. The differences between the popular models were small, and which one won depended on the rider.
Narrow or wide visor on the ABUS Timeshifter?
It depends on the rider: neither visor was consistently faster across the 9 riders who tried both.
How can I find my fastest helmet?
Test it in your own position. Our velodrome aero test includes helmet swaps alongside position and equipment changes.
Keep reading
- Aero or weight: what saves more time on a flat course and at IRONMAN Nice?
- How to hold your aero position for a full Ironman bike leg
- How to choose the right aero cockpit for triathlon
- The best bottle position on a triathlon bike
- Behind-the-saddle bottle mounts: a 25-rider velodrome test
- The ABUS Timeshifter TT helmet
- Book a velodrome aero test
