eCVT motors under the microscope: A new era for e-bikes thanks to Gobao and Avinox?

Gobao vs Avinox: Our verdict at BIKE

​No more wear and tear, and always the perfect cadence: if Avinox and Gobao deliver on their promises, their eCVTs are set to revolutionise the e-bike world. We’ve already had a go on the Gobao X1P at Eurobike, and its potential was already evident. If these motors prove to be affordable, reasonably efficient and quiet, this will be the next big thing. - Adrian Kaether, Test & Technology Editor

Ever since e-MTBs have been hitting the trails around the world, experts have agreed: the days of the rear derailleur are numbered. Enormous motor power and delicate derailleurs simply don’t mix. Even with just 85 Newton-metres on the drivetrain, derailleurs on e-MTBs burn out in fast-forward. With the power arms race initiated by DJI subsidiary Avinox, featuring power units delivering up to 150 Newton-metres of torque This is all the more true.

Why Pinion’s MGU has failed so far

The solution? Wear-free manual gearboxes, like those found in cars or motorbikes. Ideally, these would be combined with a high-performance mid-mounted motor within a single housing. This combination is known as a motor-gearbox unit, or MGU for short. And it was precisely this kind of MGU that Pinion had unveiled at Eurobike 2023. Back then, the Swabians had helped fuel the hype surrounding this technology. MGUs can be combined with robust single-strand chains or even low-maintenance drive belts. Because the gear changes take place within the engine itself, the main cause of wear is eliminated, as is any misalignment in the drive system. Even shifting whilst stationary or automatic gear changes are possible. The low unsprung mass in the rear wheel also benefits the suspension.

Pinion’s MGU could have revolutionised motor development for e-MTBs. However, the E1.12 still struggles with a number of issues: noise, jerky gear changes, weight and the battery system. Above all, the price has so far prevented it from making a breakthrough. Not everyone can or is willing to spend 7,000 euros or more on an e-bike.

What sets Gobao and Avinox apart

With Gobao and Avinox, two Chinese companies are now making a fresh attempt to do away with the rear derailleur. Both manufacturers are adopting a different operating principle to Pinion: a so-called eCVT, which adjusts the gear ratio continuously.

>> Gobao X1P: An e-bike revolution from China?

>> Avinox MG Concept: DJI subsidiary unveils MGU concept

Without getting too bogged down in technical details: Whereas Pinion uses a classic 3x4 gearbox with cogs to provide the gear ratios, Avinox and Gobao combine two electric motors and pedal input within a fixed planetary gearbox in their eCVT systems – just like in a hybrid car such as the Prius or, as with the Owuru motor from Decathlon (reviewed here).

Thanks to the clever arrangement of the components, the system does not require a conventional manual gearbox and needs significantly fewer parts. This saves money and space. And yet, the two separate electric motors make it possible to achieve an infinite variety of gear ratios.

Continuously variable automatic transmission: no need to change gears anymore

The eCVT therefore functions like a continuously variable automatic transmission. This is useful for cycling because people tend to stick to a specific cadence: 60 to 100 pedal revolutions per minute – that’s where we feel most comfortable when pedalling.

Thanks to the continuously variable transmission technology, an eCVT’s algorithm can always maintain a set cadence. The gear ratio is continuously adjusted to suit the rider. This may sound complicated, but it requires relatively few components. Gear changes or load shifts are completely eliminated and could, at most, be artificially simulated to provide a more familiar riding experience.

The disadvantages of eCVT

However, there are also drawbacks: due to the nature of the system, the eCVT can never completely decouple the electric motors from pedal input. So, at speeds above 25 km/h or when assistance is switched off, the electric motors inside continue to run, but in such a way that no more energy is output by the drivetrain than has been put in. For this control process, there must always be some residual energy left in the battery. Experts also see unresolved issues regarding heat resistance and efficiency. Furthermore, the riding experience will depend significantly on the quality of the software – and this is precisely where Avinox and DJI are considered to be particularly strong.

>> Read here to find out what some of the leading figures in the cycling industry think about MGUs with eCVT technology

Up to 150 Nm: The engines in detail

Both Avinox and Gobao rely on this technology. As far as we know, the drive systems are therefore relatively similar mechanically. One key difference: Gobao’s X1 and X1P are already nearing market readiness. With an incredibly powerful fast charger, they can deliver a charging current of up to 30 A (!). In other words: charging from 10 per cent to 80 per cent takes less than 20 minutes.

Gobao is based in Shenzhen, China, directly opposite DJI’s subsidiary Avinox, and is regarded as its main competitor. The specifications for Gobao’s X1 and the X1P sports version are as follows: up to 1,500 watts of peak power and 150 Newton-metres. The eCVT in the X1P is said to be capable of delivering a gear ratio range of 500 watts. This would put the X1P on a par with the Avinox M2S in terms of power and only slightly below conventional 12-speed derailleur systems in terms of gear ratio range.

Avinox and bike availability

According to Gobao, a number of very significant bikes are set to be launched in 2027. There are already rumours circulating, but the partnerships with well-known bike manufacturers have not yet been officially confirmed.

Avinox, however, can play this trump card. Mondraker, Megamo, Forbidden, Commencal and Canyon have already unveiled prototypes featuring the new MG Concept. As with the Gobao, the key figures are expected to be 1,500 watts and 150 Nm, with a gear ratio range of 520 per cent offering slightly more flexibility. However, the Avinox is still very much at the concept stage. At the trade fair, Avinox also announced that the first production bikes are due to go on sale in 2027. Is this realistic, or is it more of a tactical challenge to its neighbour, Gobao? In any case, the race is well and truly on.

At a glance: eCVTs – the next big thing?

Advantages of eCVTs:

• No more unreliable derailleurs
• Continuously variable transmission with automatic function, gear changes whilst stationary, and much more.
• Low centre of gravity & low unsprung mass at the rear
• Relatively few components and no wear and tear

Weaknesses of eCVTs:

• Complete decoupling is not possible
• The driving experience is heavily dependent on the software and tends to lack directness
• Price, noise level and efficiency of e-bikes still to be confirmed