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Motor doping is happening, and we've tested it

Cyclist has tested the technology found to have been used to cheat in an elite bike race - concealed motors

It's a shame that you can't win the Tour de France without speculation about doping. However, when much of that speculation concerns whether you have a tiny motor hidden in your bicycle rather than whether you've used banned substances, perhaps it's a kind of progress.

Although motors have been used to cheat, so far the only incidence ever officially detected was in the 2016 women's U23 UCI Cyclo-cross World Championships. Since then, the UCI has invested heavily in scanning bikes for signs of hidden motors.

Last year the French Prosecutor's Office also ended a multi-year investigation into mechanical doping at elite races without finding any evidence of the practice.

However, during the 2021 Tour de France, the issue again gained prominence with an article in Swiss newspaper Le Temps alleging that three unnamed riders had heard strange noises coming from the rear wheels of various racers.

The same day the article was released, a journalist asked race leader Tadej Pogačar about the possibility of his bike containing a motor. He was unsurprisingly incredulous.

According to Le Temps, talk in the peloton wasn't of a seat tube-based motor of the kind found in 2016, but of some sort of energy recovery devices like the KERS system used in motorsport or a form of electromagnetic propulsion.

Yet the idea that anyone developing technology small and light enough to be used in this way would first employ it to help a rider cheat their way to Tour de France victory, rather than using it to become extremely wealthy, seems a non-sequitur.

Vivax Assist system

Still, everyone loves a conspiracy theory.

Currently, if you do want to cheat, your best bet would still seem to be to try and hide a motor system in the frame and then sneak it past the authorities.

Systems of this kind do currently exist and have various non-nefarious purposes. We tried one out to see if it could transform us from also-rans into race winners…

Motor doping is happening, and we've tested it...

The cycling world was shocked on Saturday 30th January 2016 when U23 rider Femke Van den Driessche was found to have a motor concealed in her spare bike. The system she used was a Vivax-Assist motor, a technology that has been in development for years – largely aimed at a market of older riders keen to maintain their normal riding.

While motors are fully capable of being concealed and providing extra wattage during a race, it's not as simple as it may seem to gain an advantage from a motor.

There are various ways in which motors can be integrated into a bicycle. They can be placed in either the wheel hub or at the bottom bracket.

Hub motors, though, are complex and bulky items – certainly not fitting within a svelte carbon hub. Despite claims that electromagnetic wheels and hubs could be in use in the pro peloton, no working or even prototype samples have ever been found or pictured.

So, if one of the goals is concealment, that leaves us with a cylindrical motor inserted into the seat tube, and this technology has been around for some time.

The Vivax-Assist is the descendant of the Gruber-Assist motor, an ingenious device launched in 2008 that turns a bevel gear fastened to the crank axle and gives a power boost of around 100 watts.

The new Vivax-Assist is quieter, with a more compact and well-hidden battery. Whereas the main battery used to sit in a large seatbag, it is now located in the bottle, although the motor also has an internal battery that can power a bike for 60 minutes. The power switch, previously secreted under the saddle, is now housed at the bar-end.

Motor doping

Motor doping was an issue at the forefront of the sport well before Van den Driessche’s offence. In the infamous CIRC report into doping in cycling published in March 2015, a section on page 85 was dedicated to ‘technical cheating’.

Part of that page read, ‘The Commission was told of varying efforts to cheat the technical rules, including using motors in frames. This particular issue was taken seriously, especially by top riders, and was not dismissed as being isolated.’

Consequently, the UCI has raised the fine for contravention of Article 1.3.010 (forbidding electrical assistance) to a new maximum fine of 1 million Swiss francs (£674,000) and began implementing regular checks on bikes in the pro peloton – several hundred have already taken place at the Giro d’Italia.

One of the most famous rumours of motorised assistance surrounded Fabian Cancellara in 2010. Italian journalist Michele Bufalino posted a video alleging Cancellara’s hand movements and rapid accelerations were indicative of someone using a motor.

Another Italian, ex-pro Davide Cassani, examined the Gruber-Assist system to demonstrate how it could be used by the pro peloton. Commissaires inspected Cancellara’s bike and no sign of a motor was found, nor was the specification of his bike suitable for the motors available. Cancellara replied to the accusations by stating they were ‘so stupid I am speechless’.

It’s worth clarifying that the design of the Specialized he used would not have allowed for the Vivax motor, which could not have fitted in the seat tube.

Yet the concern has been raised at the highest level of the sport. ‘The UCI takes extremely seriously the issue of technological fraud such as concealed electric motors in bikes,’ the UCI said in a statement.

‘We have been carrying out controls for many years and although those have never found any evidence of such fraud, we know we must be vigilant.’

The UCI wouldn’t comment on whether it had reason to believe motors were being used in WorldTour road races, with UCI head of communications Sébastien Gillot stating simply, ‘It is our utmost responsibility to be vigilant, knowing that the technology exists.’

Whether the threat in the WorldTour ranks is real or unrealistic, the technology is now available to all racers, amateurs and elite riders alike, meaning there’s the possibility that criteriums and TT races could already be infiltrated with stealthy users of electric motors.

‘There’s no way of me knowing. It could have already happened,’ says Steve Punchard, UK distributor of Vivax-Assist (, when asked if the UK race scene is vulnerable to such cheating. He claims almost all of his customers have bought the unit with pure intentions – to keep up with club mates or spouses.

‘Most of my customers are coming up to retirement age,’ he says. ‘This system is really for the cyclist that wants to keep up with the people they’re cycling with now.’ The manufacturer, Vivax Drive, confirms that riders aged over 60 are the main customers for its motors.

Punchard describes one customer who raised his suspicion, though. ‘They bought a Vivax-Assist from me with the battery, but they didn’t even ask me for fitting instructions, so they must have known what they were doing.’

Pressing the button

Vivax sent Cyclist a Vivax Passione CF for test – a bike frame that has been custom-built to fit the motor, although the unit can be retrofitted into many frames. The first impression was that the bike was a little heavy at 9.9kg, but no more than one might expect from a bike with an entry-level frame. Otherwise, the frame is completely normal in appearance and feel.

The Vivax CF is made of carbon but has a reinforced seat tube to accommodate the torsional force of the motor. ‘I don’t recommend fitting it to a random carbon frame as the seat tube has to be reinforced with Kevlar,’ Punchard says.

‘I’d guess that an average carbon frame isn’t strong enough as standard, but Vivax has fitted it to carbon frames and has had success.’

Punchard speculates that any pro using one of these motors in competition would need to have their bikes redesigned to accommodate the force of the motor, as well as account for the fact that it requires at least a 31.6mm seat tube.

With the Passione CF, the motor battery and control unit is concealed in the bottle. To activate the motor, the cranks need to be moving. Once up to a reasonable cadence, the rider presses the bar-end switch and the motor kicks in. It does create a whirring noise, which is noticeable when riding solo but is unlikely to be detected in the buzz of a large pack.

With 110 watts of additional power, the speed boost on the road is tangible. Some swift calculations indicate, however, that even with the extra 110 watts, Cyclist’s power output would still be too low to compete with the likes of Chris Froome, who pumps out 6.2 watts per kilo compared to our motor-assisted 5.8.

But there are plenty of riders in the pro ranks who, if they used this motor, would boost their wattage enough to leave Froome in the dust. So perhaps it’s understandable that the UCI is worried, bearing in mind that the weight of the motor could probably still be accommodated within the UCI minimum weight of 6.8kg.

The potential for cheating with a motor is real but, having tested the system, we at Cyclist are not convinced that it is yet a problem in professional road racing. While for Van den Driessche, the motor clearly offered an advantage, the intense and sporadic efforts of cyclocross benefit from the system more. Take a glance at her ascent of the Koppenberg for more of an idea of how the motor would have been put into action. 

The Vivax-Assist is very good at what it was intended to do – offering assistance in maintaining a certain cadence and speed – but it is not a high-powered motor that will propel you to a consistent 50kmh.

On the road

Taking the unit around one of our local 6km loops on a windy day, we found ourselves a little faster than expected, but still around 30 seconds off our best time.

Experience suggests that on a stiffer and lighter build we could have ridden every bit as fast without the motor. While there is an advantage, it probably wouldn’t account for the moped-like accelerations of Cancellara if he were not already producing near-moped-like power. Also, the workings of the motor are more complex than one might assume.

Rather than simply adding extra power, the motor works to maintain a pre-determined cadence. If the system has been programmed for 90rpm, it will work to keep the pedals at that cadence regardless of the power the rider puts in, meaning that in a low gear it will quickly stop assisting you once 90rpm is exceeded.

In too high a gear, though, the motor can become overstrained and produce less power. The trick is to move into a high enough gear for the motor to be working at its maximum capacity in conjunction with the rider’s own input. The cadence the motor targets can be set by holding the on/off switch for five seconds while holding a desired cadence.

For the purposes of racing, this system would require regular adjustments to set the cadence to a useful level, which may be trickier on a lengthy climb, with repeated attacks, than on a shorter off-road cyclocross climb.

Then there’s the bulk of the system. A battery concealed in a bottle would not go unnoticed in the pro peloton, although a smaller, more covert system could be developed. ‘I think getting the motor smaller and lighter would be possible,’ Punchard says.

‘The system comes in three parts: the crank, the freewheel and the motor. So a smaller unit with only 80 watts could be used and that would still make a difference in a race. Then instead of having a 6Ah battery you could have just enough battery power for 10 minutes or so.’

The boost is out there

Intriguingly, Vivax claims that the UCI has not contacted the company as part of its investigation into the practice of ‘motor doping’, but the technology is already in common recreational use with approximately 1,000 units apparently being sold each year, and some could easily have been modified.

Systems like the Vivax-Assist will no doubt become more prevalent and, with the automotive industry honing the sophistication and power of lithium batteries and electronic motors, the technology behind it is likely to take significant leaps forward in the coming years.

With that in mind the UCI is right to be vigilant, and we can only hope that Femke Van den Driessche is the first and last culprit of motor doping.

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