Stealth bike tech of the year: Rule 28 aero base layer

Point is in terms of watts/dollar (or pound per the article) even if Rule 28’s claims of wattage savings are halved the savings are similar to an aero helmet and trump aero wheels when compared to the figures in the article below.

Yes, I understand the point re: dollars ratio….but you are missing mine.

If I have to buy an helmet anyway, then buying an aero helmet is the smart choice…and it makes my dollar / time savings equation almost nil because I have to spend that money anyway. It is not an incremental cost.

I don’t have to buy a base layer.


But most people will use base layers, especially at this time of the year (in Europe). Might as well use one that might save some W.

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You aren’t going to get much warmth from a crop top base layer….


I think I’m going to buy one. If the wattage claims are what they say this should be similar to an aero wheel upgrade. If not it’s relatively cheap and not a major concern. I have a slightly larger build, especially arms, so perhaps this purchase makes more sense than other aero hacks. IDK. The real problem is verifying if something is actually making you faster or slower. I can think of one maybe two descents that would yield good speeds with no traffic. Only problem is I’ve never experienced calm winds on them. Even almost imperceptible changes in wind can have noticeable affects on speed and completely invalidate any result.

@Power13 I understood what you were getting at.


Here’s why I tell the forum that you can’t trust your intuition when it comes to aero…actual test results of the Rule 28 base layer with the Rule 28 aero suit…vs the base layer with Black Bibs skinsuit. Vs Endura speedsuit.

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This would only be true for jerseys that are skin tight and “compliant” enough for the “bumps” in the Rule 28 to affect the surface of the jersey. If the jersey isn’t skin tight in all places, any potential aero benefit will be lost / overwhelmed by the negative aero affects of the jersey sloppiness.

Is there a TL; DR synopsis of that video? That is just painful to watch / listen to….

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That’s what would be expected isn’t it? Rule 28 base layer is more aero if paired with a jersey or skinsuit made of a smooth fabric where the textured pattern can come through, but pairing it with something that is already textured like the Black Bibs skinsuit would be detrimental as you’ve got one pattern sitting on top of another.

I hit the +10 seconds button like it was an arcade game.

He did have this slide, though. The one improvement without a pic, but I can use my imagination.


I tested the Rule28 aero base layer whilst on the track with the TT-bike. On my smooth fabric road race suit it was almost 2 digit Watts faster at 45km/h, whilst wearing it under my TT suit (texture on the upper arms) it was slower.
→ Dont just wear it, it depends.


Yeah the pedal thing caught my eye, too. Especially since I have two-bolt cleat pedals on all my bikes.

But I’m skeptical. :wink: I don’t think I could get that out of my pedals. But, hey, it’s probably not going to make them slower.

Is there a UCI rule that prevents ribbing in the skinsuit itself or something? My understanding when I first saw it was that it was designed specifically for sponsored riders/teams who are forced by the sponsor to wear a low-tech (bad) skinsuit and are trying to reduce the defecit between their kit and competitors who wear the latest and greatest. It looked like it was all about improving an old/bad/cheap skinsuit when it wasn’t possible or affordable to get perfectly placed trip seams engineered into your setup from the beginning.

That’s sort of what that youtube data suggests - potentially effective as a retrofit add-on but can probably be done better if engineered into the main garment from the start.

I guess what I’m struggling to work out is: is this just a retrofit product or are there situations where it’s preferable to engineer a two-layer system instead of a single garment?

Skinsuit fabric “height” or “texture” is UCI regulated. I dont know the exact ruling on this, but the aero base layer avoids this rule. We shall see how long until it gets banned, if at all.


Ah right that makes sense. Got to draw a line somewhere on the spectrum between silk-smooth fabric and aerodynamic prosthetics I guess.

Now that’s got me trying to imagine where we’d end up if it was unrestricted - fibreglass fairings stitched into skinsuits so we’ve all got long tails on our backsides and fins on our biceps and hamstrings? We’d probably think we look like sharks while the rest of the world just sees us dressing up as giant sperm! :joy: Seems the UCI is looking after us after all…

Look at what Revolver / Joe Skipper do in the Triathlon world :slight_smile:

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To clarify that is for SPD SL pedals. As in three-bolt road pedals.

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but still earth air, I bet. :wink:

Hey Everyone,

Sam here from Rule 28. Great to see the Aero Base Layer has you all talking. It’s really taken the WT by storm and we have numerous teams and individual riders wearing them now.

To clarify a point I’ve seen above. The aero base layer WILL NOT work with jerseys/skinsuits that have a striped arm fabric. This creates interference and leads to greater drag overall. Most mesh fabrics still work but it varies. If you can. Please stick to smooth armed jerseys/skinsuits like our Neo Suit.

If you’ve got any questions about kit please reach out and I’ll be happy to help. We can also be reached at

We have kit available to test here:

US: A2 Windtunnel


Consider making white tops for your suits. Heat matters.