AeroCoach free data on aerodynamics and rolling resistance

UCI Time Trial regulations for 2026 onwards, and what to expect on race day

Wed, 21 Jan 2026 10:59:59 GMT

pdatedU When you turn up to a time trial held under UCI regulations, your bike will be measured in a number of different areas, such as the saddle and handlebar extensions.

In the video below are the latest UCI regulations for 2026 and beyond, explaining how your height category affects the measurement limits you are permitted and tips and tricks to ensure your bike passes the check on race day.

If you are using our Ascalon extensions we offer a range of options to achieve all possible combinations for the three rider height categories, just scroll down below the video for info.

Remember:

Riders in UCI Height Category 1 (0-179.9cm tall) can have a maximum pad to shifter height of 100mm

Riders in UCI Height Category 2 (180-189.9cm tall) can have a maximum pad to shifter height of 120mm

Riders in UCI Height Category 3 (190cm or taller) can have a maximum pad to shifter height of 140mm

When determining your optimum setup using the dimensions below, please note that the Inward gripper option for Ascalons results in the same reach/height as long grippers with Shimano 1 button SW-R9160 shifters installed. Inward grippers require either Shimano SW-R9150 climbing shifters, SRAM Blips or SRAM Wireless Blips.

Category 1

Category 2

Category 3

Cycling wheel rim width vs tyre width - is there a simple relationship with aeroydnamics?

Mon, 04 Aug 2025 14:54:49 GMT

It has often been said that to have good cycling wheel performance, there is a "rule" that the external rim width of a wheel should be at least 105% of the width of the tyre, or that there is a simple relationship/formula that will predict the aerodynamic performance of a wheel based on rim width vs tyre width.

Whilst this may have rung true with older models of wheels which shared a V shaped or flat sidewall shape, modern rims come in a range of shapes which vary in terms of their aero performance due to a number of factors, not just external rim width. Rim depth, the vertical location of maximum rim width, nose profile (at the spoke entry point), dropoff angle to nose profile and "brake track" angle are all critical components that add up to allow for a fast rim shape.

The data below is a subset, taken from a wind tunnel test of deeper time trial/triathlon wheels, both with normal spokes and composite multispokes (3 and 4 spokes), exploring if there is a simple relationship between the external width of a wheel and its performance, all with the identical same tyre.

Track cycling inner tube Crr testing: TPU vs latex

Wed, 30 Jul 2025 16:55:56 GMT

Reducing rolling resistance is imperative to improved cycling performance, particularly during high speed track cycling. A tyre with a high rolling resistance will require more power to travel at the same speed, whilst a low rolling resistance tyre requires less power.

We have previous shown that top end clincher tyres, such as the FMB/AeroCoach Pista Ultra 3000 have extremely low rolling resistance. We have also found that for road tyres at road pressures, latex inner tubes are the best option for reducing Crr compared with TPU tubes.

In this test we explore the difference between TPU and latex tubes but at higher, track relevant pressures and with a track specific tyre rather than a road tyre.

FMB/AeroCoach Pista Ultra 3000 track clincher & tubular tyres

Fri, 04 Apr 2025 15:40:16 GMT

AeroCoach has collaborated with French artisan tyre makers FMB to ensure that track tyre development is up to scratch. With tyre companies that previously made fast tyres dropping track tyres from their range, or in some cases disappearing altogether, it is more important than ever that riders have the best equipment available to go as fast as possible, both professionals and amateurs.

Continental Aero 111 wind tunnel & rolling resistance data

Wed, 27 Nov 2024 13:14:56 GMT

The new Continental Aero 111 tyre is designed to provide maximal aerodynamic advantage by use of a custom tread pattern.

However there is often a tradeoff between aerodynamics and rolling resistance (Crr) in terms of how tyres are shaped and how this affects Crr, and understanding how the two combine to provide the overall fastest system is essential when looking to improve performance on the bike.

Clincher tyre rolling resistance performance in track cycling

Fri, 16 Feb 2024 14:10:32 GMT

The data below is a list of clincher and tubular track tyres. Please do check back for updates!

Understanding road bike fit aerodynamics - how to get more aero!

Mon, 23 Oct 2023 10:22:00 GMT

Chris Hall came to visit us at AeroCoach HQ in order to improve his bike fit on the road bike, specifically focusing on aerodynamics for road bike time trials.

In this video Dr Xavier Disley runs through what to look for to improve your road bike fit for aerodynamics: discussing narrow handlebars, turned in levers, torso angle, aero helmets and more, see the video below!

Tubular track tyre rolling resistance

Mon, 22 May 2023 12:29:07 GMT

The data below is a continually updated list of track tubular tyres. Please do check back for updates!

How to hold aerobar extensions

Wed, 06 Jul 2022 14:22:07 GMT

Aerobar extensions, whether used on a triathlon/TT bike or using a clip on system on a road bike, come in a wide variety of sizes and shapes. AeroCoach has been testing riders since 2012 and we've noticed a few trends into how you can optimally hold your extensions for aerodynamics as well as comfort.

Your body accounts for around 80% of the aerodynamic drag of the bike and rider system. Your optimal stack height, extension reach and elbow width for aerodynamics will be individual and can only be determined by conducting an aero test, but as well as these variables there are differences in how riders hold their hands on extensions, and in this test we explored some general guidelines which you can follow. Don't forget, a lower aerodynamic drag will result in less power required to travel at the same speed, or for the same power will cause an increase in riding speed, when not travelling up steep gradients.

Front light aerodynamics

Thu, 23 Dec 2021 16:02:02 GMT

In the UK, having a front light when racing time trials is now obligatory under CTT regulations. Not only this, but also some events are conducted over long periods of time (eg. 24hrs, or multi day ultra endurance rides) and so with front lights being a necessity we explored the impact of front lights on racing aeroydnamics in the wind tunnel.

To purchase the AeroCoach TT front light mounts click here

Clip on aerobars

Fri, 29 Oct 2021 14:32:24 GMT

Using clip on aerobars on a road bike is a great way to improve your aeroydnamics.

Your body accounts for around 80% of the aerodynamic drag of the bike and rider system. In this test we explore the impact of holding different positions on a standard drop handlebar, alongside an aerobar position using a set of Ascalon extensions. A lower aerodynamic drag will result in less power required to travel at the same speed, or for the same power will cause an increase in riding speed, when not travelling up steep gradients.

UCI banned road bike position aerodynamics

Sun, 18 Apr 2021 20:03:13 GMT

The UCI have changed their regulations on road bike positions, outlawing some positions for safety reasons.

In this test we explored a range of positions that you can hold on the road bike, to see how they all compared for aerodynamic drag. A lower aerodynamic drag will result in less power required to travel at the same speed, or for the same power will cause an increase in riding speed, when not travelling up steep gradients.

Road tubeless liners and rolling resistance

Wed, 25 Nov 2020 20:58:20 GMT

In previous tests we have shown the importance of rolling resistance on cycling performance. A tyre with a high rolling resistance will require more power to travel at the same speed, whilst a low rolling resistance tyre requires less power.

In this experiment we explored how adding a tubeless liner to a Continental GP5000 tubeless tyre affected the rolling resistance.

Tubeless sealant and rolling resistance

Mon, 15 Jun 2020 17:11:32 GMT

In this experiment we explored how varying the amount of sealant in a tubeless compatible tyre affects the rolling resistance.

Aerodynamics of racing tyres

Wed, 27 May 2020 14:07:18 GMT

As well as rolling resistance being extremely important for the performance of a tyre, aerodynamic performance shouldn't be overlooked. A tyre that performs well in terms of rolling resistance (a lower rolling resistance is faster and requires less power to travel at the same speed), could potentially be limited by aerodynamics that cause a penalty over other, more aero tyres.

We have previously shown that a Continental GP 5000 tyre has excellent aerodynamic performance, beating the GP 4000 which was the aero tyre of choice for many years. However, we've also shown that a GP 5000 doesn't have the lowest rolling resistance of racing tyres, so how does it compare if we take both rolling resistance and aerodynamics into account?

Get more aero for free with GCN!

Mon, 25 May 2020 08:55:19 GMT

GCN came to visit us in the wind tunnel in order to find out how you can make yourself more aerodynamic with some simple tips and tricks. Have a watch of the video below!

Modern tyre pressures & AEOX wheel data

Fri, 22 May 2020 17:37:20 GMT

Looking for more information about setting up your AEOX® wheels? See below for all the tyre and aerodynamic information.

Also please feel free to use our handy tyre calculator to check what tyre pressures you should be running with your AEOX® wheels, on standard tarmac roads. Please use the tyre pressures as a guide, you can lower pressures for wet conditions or very rough surfaces, or increase them for super smooth roads. Happy riding!

Enter your weight in kg including clothes and helmet.
Nominal tyre width is what is written on the sidewall (actual tyre width will be greater when installed on AEOX® wheels due to the 19.6mm internal rim width).
Recommended PSIs should be used front and rear for time trial/triathlon bikes, and for road bikes you can decrease 2-3psi for the front wheel.
Don't forget to press "Calculate"!

Continental GP5000 & GP4000 wind tunnel data

Fri, 22 May 2020 17:14:43 GMT

Cyclists have long known about the importance of rolling resistance in selecting tyres for racing, group rides or even general training. A tyre with a high rolling resistance will require more power to travel at the same speed, whilst a low rolling resistance tyre requires less power.

There is often a trade off between rolling resistance and puncture protection, however - with the fastest rolling tyres often being the worst for punctures!

Continental's Grand Prix (GP) 4000 was renowned for being both puncture resistant as well as having good rolling resistance, and is also regarded as an "aero tyre" given that the tread pattern often performs well in wind tunnel testing.

Water bottle aero testing

Fri, 22 May 2020 17:03:48 GMT

WHERE SHOULD YOU PUT A WATER BOTTLE ON A TT/TRIATHLON BIKE?

For triathlons and long distance TTs, having to decide where to put your hydration can be quite a conundrum. You need to make sure you have hydration available but could you be slowing yourself down? In this data set we'll be looking at common places to put water on the bike only, and how that affects the aerodynamic drag for one individual rider.

As with many components of aerodynamic drag, water bottle placement can be very personal. The following data set is intended to be used as a guide to highlight that making sure you choose a good location for your hydration will keep you going fast, and not costing lots of drag!

Inner tube rolling resistance

Fri, 22 May 2020 16:29:20 GMT

INTRODUCTION

Cyclists have long known about the importance of rolling resistance in selecting tyres for racing, group rides or even general training. A high rolling resistance will require more power to travel at the same speed, whilst low rolling resistance requires less power.

We have performed tests on a large number of different inner tubes to see how they affected rolling resistance. Construction varied from plastic (Tubolito - S Tubo & Road, Schwalbe Aerothan, Revoloop Ultra Race), latex (Challenge, Vittoria, Michelin, Vredestein) as well as butyl (Continental, Schwalbe, Michelin, Hutchinson)

We used a Continental GP 5000 clincher tyre in 25mm to perform the test

Racing tyre rolling resistance

Wed, 20 May 2020 17:52:46 GMT

The data below is a continually updated list of currently available racing tyres, in both tubeless and clincher format. Please do check back for updates!

LOTUS 110 Wind tunnel test

Tue, 12 Mar 2019 23:07:00 GMT

INTRODUCTION

Back in the 1990s there were a huge prevalence of exciting bike frame designs - using non traditional frame geometries and shapes in the cycling and triathlon worlds.

One of the most iconic bikes was made by Lotus, and the Lotus 108 track bike was piloted by Chris Boardman to his individual pursuit win in the 1992 Barcelona Olympics against Jens Lehmann.

Made from carbon fibre, with an offset rear wheel and monostay design (the left hand chainstay and seat stays were removed, as well as the left fork leg) after this success the Lotus 108 was updated to the 110 - but much of the design and general shaping was retained.

This new design was again ridden by Chris Boardman to Tour de France prologue victory in 1994, as well as his "ultimate" Hour Record distance of 56.375km.