Sam here, founder of Rule 28 (We make aero clothing).
We get tagged in questions about kit and more generally, all things aero so I thought it would be a good opportunity to answer people’s questions in one place about kit, aero or the cycling industry in general.
A bit of forewarning, the answer to quite a few aero questions is ‘it depends…’ but I’ll do my best to answer in as much specific detail as possible.
Drop a question here if you have one and let us help you get faster!
So the first thing we need to address is speed is basically power over drag. Forget about Watts per Kg, Watts per CdA (aero drag) is what really matters. The biggest factor in this is your body ~80% of aero drag is your body, and of that, 80% is the shape itself. The remaining 20% is what we can improve with clothing.
We’re also going to factor in the $ per Watt saved (roughly).
Shaving your legs - it’s free and from a style point it’s probably something you should do anyway.
Bike fit. Combining aero testing and bike fitting. we have a blog on how to do DIY are testing what can be found here: Aero Testing at Home: Step-by-Step Guide for Cyclists – Rule 28
Another thing to test out is your Watts/Heart rate over ~10min threshold. This will give you an idea of how sustainable the power production is. A position that for the same speed at a given power, that you achieve with a lower HR is your best option as it will be more sustainable.
Aero Socks. These are basically the only clothing upgrade that’s guaranteed to make you faster. Skin suits can vary between people. Also, $ per Watt saves they’re great.
4 Aero bars kind of fall into bike fitting too as it’s not the pars that really make a difference. It’s the fact they’re narrower on the hoods that pulls your arms and shoulders in. For this reason if put them here but if we’re talking about aero bars in isolation they would be in last place.
5 Aero Skin Suit. After bike fit, this is likely the greatest gain in terms of raw savings there is to be had. It’s worth testing out multiple suits if you can as there is variance between riders. Cost per W is higher than aero socks,
6/7 It’s a toss up between helmet and wheels IMO as it depends what you’re upgrading from. Cost per W for wheels tends to be worse. For TT riders a larger size also tends to be the faster option if your head is in line with your shoulders.
8 Last place is frame. It’s very expensive for top brand vs. an entry level. It’s much more important that the frame allows you to achieve a riding position that works for you.
How does aero savings of all of these clothing/components/frames/etc change when riding in a pack? Let’s say at 40kph, a rider needs 300w to maintain speed, and some clothing change results in a 3w savings, so 297w and 1% saving. If that same rider is now 4th in a paceline and now only required 200w to maintain 40kph, will that same clothing change result in a 1% savings, thus 198w? Is the answer more complicated depending on what clothing/component is changing?
This is looking at the rider as a whole. Aero socks/wheels as an intervention could actually maintain a higher % of the saving in a peloton (compared to riding solo) as the mass of air displaced by the groups legs is less than the torsos, and this air, being closer to the ground, will be both less turbulent and not as effected by riders moving through it.
This is my new favorite thread on here. Thanks Sam. I’d go buy something, but I already picked up a gravel suit from you this winter that has yet to be worn.
How much for items like race suits, socks how much does the cost of the kit effect the gains?
You can get a race suit for 70ish quid, socks for a tenner plus some gloves for twenty-ish
totalling £100 give or take or have a sky’s the limit pro tour kit.
I’d guess the world tour kit is faster but just how much faster.
There’s no direct correlation between price and aero performance. You can get decent kit pretty affordablly especially last season’s styles in sales.
High performance fabrics are expensive, so is the R&D to find out what works best where. So fast kit will (and should) cost more than slow kit. You’re paying for all the behind the scenes work vs. Someone just guessing or ripping another brand off. It’s also true that someone can just try and charge a lot for a ‘pro team’ kit that’s never been near any testing.
Look for published data and independent use. If it’s being used by people who aren’t paid to wear it, the. That’s a pretty good sign.
As an aside, gloves aren’t worth it really for aero. If you want to race in gloves, then an aero mitt will cost you less than a non aero mitt. Our TT gloves are the only gloves we’ve tested that actually reduce your drag, but even then it’s 1-2W.
The biggest source of drag is your body. It’s worth ensuring you’re as aero as possible before moving focus to kit and equipment. Also, if you can DIY aero test it won’t cost you anything!
I’d still 100% wear mitts to race or for gravel etc as the protection is worth the cost. If you need the extra padding to avoid numb hands too then for sure wear gloves. You’re going to be better off in an aero mitt. But for pure $ per W, there are other things to go for first like aero socks.
Yes, whilst an optimised overshoes will likely provide a little greater benefit than an aero sock and laced shoe, in peak summer the comfort factor could make more of a difference to performance.
Our overshoes enclose the heel cup to shroud the rubber pad on the heel which will help save a little extra vs. an aero sock, but a clean lace shoe is pretty slippery now.
You have to wear kit, so it may as well be aero. Whilst the speeds you start to see a noticeable impact at are 30kph+.
For long, slow races, even though the absolute number of Watts saved would be less, the total energy saved and therefore effect on finish time will be greater.
That’s basically it for me. I normally don’t like to wear gloves, but I figure sometimes I should have some protection so I might as well use your aero mitts.