Faired recumbent land speed record: Behind the scenes with Aim93

Faired recumbent bikes are incredible machines capable of reaching speeds of 80 to 90 mph, solely off human power.

These speeds have been made possible by cutting-edge engineering, pushing the boundaries of performance, and raising the prospect of dizzying new recumbent land speed records.

Ollie Bridgewood recently visited the Aim93 team at London South Bank University who have been building their own machine in an attempt to break the world record. While there he gained some intriguing insights from the engineers and riders who are responsible for powering these incredible machines.

What is a faired recumbent?

Before we learn what Aim93’s recumbent connoisseurs had to say, let’s clear up one small question: what is a faired recumbent?

Designed for speed, they’re basically bullets on wheels. The recumbent element refers to the laid-back, reclined position of a rider on the bike. Creating the bullet shape, the rider and bike are covered by an aero fairing.

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Faired recumbent bikes are much more aerodynamic than road bikes.

It’s a very aerodynamic combination resulting in a machine that is up to 20 times more aerodynamic than a normal upright bike, and they’re much faster too.

How fast can faired recumbents go?

In the world of faired recumbents, speed is the name of the game, and the aerodynamic designs lead to some eye-watering velocities.

How fast? As Barney Townsend, a senior lecturer in engineering and product design at London South Bank University, explains, they’re not speeds you’d reach on a regular bike.

“The world record currently stands at 89.5 mph on a bicycle, with very little material between the rider and the road."

In an impressive combination of engineering and human power, these speeds are achieved on flat roads. There’s no help from any downhills or gravity, and the power is purely generated from the rider.

“The course where they hold the World Human Powered Speed Challenge is a five-mile long, arrow-straight road in the northern Nevada desert with a less than a one-percent gradient across the length of the road.”

It’s on similarly flat terrain that Barney and his team are hoping to one day break the 89.5 mph record. Their mission? Reaching the dizzying speed of 93 mph, the inspiration for the Aim93 team name.

“From the various simulations we’ve done and what we know about top-end, human-powered capabilities, what we think we can do with the aerodynamics, we think 93 mph is probably possible.”

Achieving 93 mph

A 4 mph increase may not sound like much but it’s a huge leap and one that’s not easy to achieve.

At those speeds the power of the rider becomes less significant and any advantage has to be gained through aerodynamic advances.

“At that stage it’s all in the aerodynamics. Assuming we have a relatively consistent top-level power delivery from the highest athlete we can find, the relative proportions of the losses in the drivetrain become much less,” Barney explains.

If you’ve already got a high-performing rider, there’s little scope in terms of adding power. Plus the efficiency will remain fairly consistent whether riding at 89 mph or 93 mph. The only solution is making the recumbent more aerodynamic, but how do you make something that is naturally designed to be fast even more aero?

“So the optimisation at this point will be, as they do in Formula One, to shape the cockpit around the driver and they bring it (bodywork) all in as closely as they can.”

“A bit like getting into a toothpaste tube”

This Formula One-inspired design leads to a snug cockpit, or as recumbent rider Russell Bridge describes, it’s “a bit like getting into a toothpaste tube”.

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Riders sit in small cockpits.

Not ideal for anyone with claustrophobia then. It also poses further problems for the riders who have to generate incredible power. To get his recumbent up to speeds of 74 mph, Russell averaged around 280 watts on the run-up and then 450 to 500 watts in the sprint phase.

Those numbers aren’t mind-blowing on a regular bike but on a recumbent it’s much more difficult to generate power.

“Recumbents tend to recruit a different group of muscles, so you need to be fit enough to put the power out in the position,” Russell explains.

“And then you need to have lots of recumbent experience because what tends to happen when you start sprinting on a recumbent is that your head moves from side-to-side which takes the bike over the road. So you need experience in keeping it steady and putting the power out.”

Most records are attempted on wide two-lane roads but even these can quickly become narrow at high speeds if a recumbent starts rocking.

Becoming a recumbent rider

Becoming a recumbent rider isn’t something you simply stumble into (we’re not entirely sure how you start).

Without wanting to sound too much like a scene out of Taken, it requires a certain set of skills. OK, we’ve made that sound a little more dramatic but recumbent riders have to train differently to an average rider.

“It’s a lot of power tests, as well as V02 workouts and strength training,” Mozes Baiden, Aim93’s resident recumbent rider, explains.

“The strength training includes leg presses, squats as well as body strength exercises to warm up initially. But it’s primarily focussing on leg presses to isolate muscle groups and squats to build up strength levels.”

It’s a similar training regime to that used by track cyclists and one that will send a shiver down the spine of skinny road cyclists who are usually more than a little averse to strength training.

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Recumbent riders focus on strength training to generate the high power required.

The team are still some way off a record attempt, having achieved speeds of 65 mph at the World Human Powered Speed Challenge in 2022, but Mozes believes that he’s currently capable of putting out enough watts to reach speeds of 84 to 85 mph.

That’s from 400 watts in the run-up and 500 to 550 watts in the sprint stage, seriously impressive in a recumbent position.

The world of recumbent record attempts is fascinating and we’d like to thank Aim93 for allowing us a peek behind the scenes.

You can follow the work and progress of the team on their website here.

Oliver Bridgewood

GCN Tech Presenter

PhD Chemist turned cycling enthusiast, bringing the lab coat to GCN Does Science