How Much Do Rule 28 Products Save? Wind Tunnel Data for Every Product

How Many Watts Do Rule 28 Products Save?

Rule 28's One Aero Socks save 4.07W at 40 km/h. The One TT Suit saves up to 13.43W at 45 km/h. The Neo Overshoes save 9.97W at 50 km/h. Every figure on this page comes from wind tunnel testing at the Silverstone Sports Engineering Hub, with the test speed, baseline garment and methodology stated for each result.

Most aero clothing brands publish a single headline number with no context. A watt saving is meaningless without three things: what speed it was measured at, what it was measured against, and who measured it. This page gives you all three for every product we make, including the results that don't flatter us.

Quick answer: the biggest savings

Important: two different types of test

Our products are tested against two different kinds of baseline, and it matters when you compare them.

Against a non-aero equivalent — our aero socks are tested against a standard cycling sock. This tells you what you gain by switching from ordinary kit.

Against our own previous generation — our suits and overshoes are tested against the Rule 28 product they replace. These baselines were already fast, so the numbers represent a gain on top of an already-aerodynamic garment, not a gain over ordinary clothing.

A 4W saving over a normal sock and a 13W saving over an already-fast skinsuit are not the same kind of number. We've kept them in separate tables below for that reason.

Aero socks: tested against a standard sock

Independently conducted by ATP Performance, 25 March 2025, at Silverstone Sports Engineering Hub. Rider: Rowan Baker (Raptor Factory Racing). Bike: Raptor RL1. 0° yaw, 30–50 km/h in 5 km/h increments, 30-second runs, constant cadence, pre-tared and calibrated before each run. Every pair was new. All products tested were donated to SSEH and are available for independent verification.

Baseline: Rule 28 Pro Socks (a standard, non-aero cycling sock).

Positive numbers = less power required = faster.

What this means. The One Aero Socks saved power at every speed tested, peaking at 4.07W at 40 km/h — typical road race and club run speeds.

The Aero-Ish Socks are a different product with a different job. They combine a standard sock's fit and comfort with a partial aero benefit, and the data shows exactly where that trade-off sits: they help between 40–45 km/h, but at 50 km/h they were 9.23W slower than a plain sock in this test. If you race above 45 km/h, buy the One Aero Socks. If you want a comfortable everyday sock that's a bit faster at normal riding speeds, the Aero-Ish is the right choice. We'd rather tell you that than sell you the wrong product.

On the older 12W figure. You may have seen Rule 28 aero socks quoted as saving "over 12 watts." That number came from a different test: a different rider, a different baseline sock, and a top speed of 60 km/h rather than 50 km/h.

Those aren't small differences. Aerodynamic savings are highly rider-dependent — leg shape, position, and how the fabric sits all change the result — which is why the same product can test at 12W on one rider and 4W on another. Neither number is wrong; they're measurements of different things. You can't directly compare them, and we'd be misleading you if we presented them as though you could.

What we can say from testing the same rider on the same day: our current aero socks outperform the previous generation. When we tested the One Aero Socks against our older aero socks under matched conditions, the newer product was clearly faster — enough to justify the significantly higher material cost. That test is here →

The figures on this page are from our most recent, independently conducted test. They're the ones we'd want you to judge us on.

[Shop One Aero Socks →] [Shop Aero-Ish Socks →] [Read the full sock test, including competitor results →]

Skinsuits: tested against our previous generation

Testing at Silverstone Sports Engineering Hub using a 3D-printed mannequin of a time triallist on a TT bike, allowing precise measurement of how small changes to seams and fabric affect drag. 40–60 km/h in 5 km/h increments.

One TT Suit vs TT Suit 2.0

Read the crossover. The One TT Suit is faster through 40–50 km/h, where the overwhelming majority of time trials are actually raced. Above 50 km/h the advantage reverses. If you regularly race above 50 km/h, the Neo Suit is the correct product for you — it's built for exactly that range.

In real terms: over a flat 10-mile TT at 50 km/h, a 6.45W saving puts you roughly 72 metres (237 feet) ahead of the same rider in a TT Suit 2.0.

Neo Suit

The Neo Suit is our fastest skinsuit, built with an integrated double-layer sleeve rather than requiring a separate base layer. It was tested at Silverstone against both our previous-generation Neo Suit (worn with a separate Aero Base Layer) and the One TT Suit, using a 3D-printed mannequin across 40–60 km/h.

Read the two columns. Unlike the One TT Suit, the Neo Suit stays faster than the TT Suit 2.0 at every speed tested — there's no crossover. And crucially, its advantage over the previous Neo Suit grows as speed rises: +10.53W at 40 km/h widening to +34.22W at 60 km/h. This is the suit built for riders racing above 50 km/h, and the data shows exactly why — the faster you go, the more it saves.

In real terms: at 50 km/h the Neo Suit needs 419.34W where the One TT Suit needs 423.62W and the previous Neo Suit needed over 435W. At 60 km/h — sprint and elite TT speeds — it saves 34.22W over the previous generation. That's not a marginal gain; it's among the largest single-garment savings we've ever measured.

[Read the full Neo Suit test data →]

A note on our road race and triathlon suits. The One and Neo Road Race Suits and Triathlon Suits use the same fabrics and construction principles as the TT suits tested above. The figures on this page come from TT suit testing; the road and tri variants have not been separately wind tunnel tested, and we're not going to present TT numbers as if they were.

[Shop One TT Suit →] [Shop Neo Suit →]

Aero overshoes: tested against our previous generation

Tested at Silverstone Sports Engineering Hub on a pedalling rider holding a constant 90 RPM cadence, 25–50 km/h.

At 50 km/h the One Overshoes save 6.76W and the Neo Overshoes save 9.97W versus our previous generation.

In real terms: over a flat 10-mile TT at 50 km/h, the One Overshoes put you about 41.8m (137ft) ahead of the previous generation. The Neo Overshoes extend that to roughly 60.4m (198ft).

[Shop Neo Aero Overshoes →] [Read the full overshoe test data →]

Cost per watt saved

The honest way to compare aero upgrades is cost per watt. Two caveats before the table:

1. Socks are measured against ordinary kit; suits and overshoes against already-fast Rule 28 products. A cheap watt gained over a plain sock isn't directly equivalent to a watt gained over a race skinsuit.
2. Watt savings vary with speed. We've used each product's saving at 45 km/h where available, since that's a realistic race speed for most riders, and noted where a different speed is used.

The takeaway. Aero socks and overshoes remain the cheapest watts available in cycling — a fraction of the cost per watt of deep-section wheels, an aero frame or a TT helmet. If you're building race kit from scratch and buying in order of return, start with socks, then overshoes, then the suit.

But read the Aero-Ish caveat. On paper it's the cheapest cost per watt on this page. That number only holds below roughly 45 km/h. Above that it's slower than a plain sock. Cost per watt is a useful shortcut, not a substitute for reading the actual test conditions.

Frequently asked questions

How many watts do aero socks save?

Rule 28's One Aero Socks saved 4.07W at 40 km/h and 3.36W at 50 km/h versus a standard non-aero cycling sock, in independent wind tunnel testing conducted by ATP Performance at Silverstone Sports Engineering Hub in March 2025. Savings vary by rider, speed and the sock being compared against.

Are aero socks worth it?

On cost per watt, aero socks are among the cheapest aerodynamic gains available in cycling — roughly £10 per watt saved, compared with hundreds of pounds per watt for aero wheels or frames. Whether that's worth it depends on whether you race or ride at speeds where the gain applies.

Which Rule 28 suit is fastest?

The Neo Suit, which is designed for speeds above 50 km/h. Below 50 km/h the One TT Suit is the right choice — our testing shows the One TT Suit is faster than its predecessor through 40–50 km/h, with the advantage reversing above 50 km/h where the Neo Suit takes over.

Where does Rule 28 test its products?

All Rule 28 wind tunnel testing takes place at the Silverstone Sports Engineering Hub in the UK. Our March 2025 aero sock comparison was conducted independently by ATP Performance, who managed data collection, setup and methodology. All products from that test were donated to SSEH and can be independently verified.

Do aero socks work at all speeds?

No. Aerodynamic gains are speed-dependent and cannot be extrapolated — a product that performs well at 40 km/h may perform differently at 50 km/h. Our own Aero-Ish Socks demonstrate this clearly: they save power between 40–45 km/h but were slower than a plain sock at 50 km/h.

Our testing principles

We publish results that don't flatter us. The Aero-Ish Sock's 50 km/h result and the One TT Suit's crossover above 50 km/h are both on this page.

We state the baseline. A watt saving means nothing without knowing what it was measured against.

We use independent conductors where we can. Our March 2025 sock test was run by ATP Performance, and every product tested was donated to Silverstone Sports Engineering Hub for anyone to verify.

Individual results vary. All testing was conducted on a single rider or mannequin. Trends tend to hold between riders — the fastest product for one person is usually the fastest for another — but the actual watts saved will differ depending on your body, position and bike.

Last updated: [09/09/2026]. Testing conducted 2024–2025 at Silverstone Sports Engineering Hub.