Crank-based gearbox in development

Polish developer looks to launch efneo 3-gear system

The efneo system is still in development

You often hear that there is no need to reinvent the wheel, but it does seem that every other part of the bicycle is completely open for discussion. Many designers and engineers have attempted to change the basic drive train, and one of the most common solutions has been internal gearing located in the rear hub. But Polish developer Stefan Migaszewski has looked to another solution, one that puts the gearbox at the bottom bracket.


Migaszewski’s solution would locate the gearbox in the bottom bracket shell, which would offer the ability to shift gears while stationary and while pedaling. This would also make it easy to go to the lowest gear at a stop, much like shifting into first gear in a car.

With three effective gears of approximately 24, 33 and 45 teeth, the efneo system as it is called would thus replace the front derailleur, but not necessarily the rear derailleur.

It is similar to Truvativ’s HammerSchmidt crank, a system that offers effectively two front gears at the flick of a switch.

“We assume efneo is not a competitor to rear-wheel systems; it is rather a complementary solution,” said Wiktor Migaszewski, Stefan’s son. “With a good rear-wheel system like Shimano Nexus 8 you have 300 percent gear ratio. It is nice if you are living in a flat area, but a typical sport bike with derailleurs offers 600 percent gears ratio and this is what makes biking comfortable.”

The efneo system is still in development:
The efneo system is still in development

“With efneo at the front and some other hub-based system on a rear wheel you have over 600 percent gear ratio and no derailleur,” Migaszewski told BikeRadar. “It looks better, it’s easier to maintain and it gives the same comfort.”

This system would not be limited to use with a current chain system either.

“I think efneo is perfect for a belt drive system,” he added. “If paired with a rear-wheel hub gearbox, of course. If you want to pair it with a rear-wheel derailleur, you need chain because of chain skewing.”

The efneo system is patent pending in several markets and is still in the concept stage, so it won’t be seen at major trade shows such as Eurobike or Interbike in the near future. But the gearbox could be a future tech to watch for, considering the benefits it could offer.


“There are a few advantages that are common for all gearboxes – they look better and are easier to maintain,”  Migaszewski  added. “The main advantage over front derailleur is that it makes possible to change a gear both while pedaling and while stationary. Even if you are starting uphill you can change the gear to the lowest and starting is easier. With a derailleur it is impossible while stationary. We also assume changing gears with a front gearbox is quicker and easier than with most of front derailleurs.”