Eurobike innovation: The next big thing? Will we all soon be riding bikes with motor-gearbox units?

​The MGU combines an electric motor and a gearbox – in other words, the gear system – into a single unit. This has advantages, but also disadvantages. Until now, there was the Pinion gearbox, but it failed to catch on. At this year’s Eurobike, Asian manufacturers Gobao and Avinox, of all companies, showcased new models. Design engineer Peter Denk says: “Bosch certainly has something like this in the pipeline too, but the Chinese were quicker off the mark. It’s a right shame.”

What is an MGU?

​The MGU (Motor Gear Unit) is an assembly that combines the motor, gearbox and gear-changing mechanism into a single unit. Advantages: less maintenance, gear changes whilst stationary, better weight distribution, longer service life of the drive system, smooth gear changes. Disadvantages: greater weight, high cost, potentially more complex repairs. Gobao and Avinox showcased new models at Eurobike.

Three blokes, three opinions.

Here, designers Peter Denk and Lutz Scheffer, along with Deputy Editor-in-Chief Florentin Vesenbeckh, have their say.

Peter Denk, kinematics expert and visionary

​The rear derailleur has to go. Continuously variable transmissions are the only way forward for mountain bikes – and indeed for city bikes too. No rear derailleur, no interruption in traction, no compromises.

Gears without any interruption in drive? Go on, have a go at that. MotoGP has been working on this for decades, at enormous expense, and it’s still a nightmare. Hyper-complex, too heavy, too prone to failure. So, as far as I’m concerned, that’s a dead end.

What Gobao and Avinox are doing now is an exciting approach. And to be honest, I’m absolutely keen on it. It’s a real shame that the Germans have missed the boat on this. What really gets me excited is that you save 700 to 900 grams of unsprung weight on the rear wheel. Have a go on a brutal section of roots and then tell me it makes no difference. It’s a double win – the suspension responds better, and the whole dynamic is simply in a different league.

And then there’s this: without a rear derailleur, the chain stays fixed in one position. Zero chain misalignment. That means I can completely enclose the chain – neat, protected, low-maintenance. This opens up completely new possibilities in bike design. In short: MGUs have what it takes to be a major innovation; let’s see if it comes to that.

​Florentin Vesenbeckh, BIKE test rider and deputy editor-in-chief

A truly impressive gear-shifting system is seen as the ultimate challenge for the mountain bike industry. So far, no system has really proved itself in competitive use. If Gobao or Avinox succeed, it would be the next revolution in the e-MTB market and good news for all e-bikers. The Chinese players are certainly capable of great things, but so far they’ve only looked impressive on paper.

​Lutz Scheffer, a heavyweight in the world of design, Rotwild

Yes, because the automatic transmission, belt drive, low maintenance requirements and reduced unsprung mass are strong selling points. However, for riders prioritising top speed, low assistance and maximum efficiency, the classic mid-drive motor with derailleur remains the gold standard. Aside from comfort, it is above all system efficiency, weight balance and real-world performance that will determine the future of the concept.