Mubea from Germany introduced a high-end mid-drive at Eurobike 2018 that has a gearbox for the motor to use, and…the gears are located by the motor instead of the wheel.
Mubea / Muhr & Bender
This actually a just a prototype that Mubea is showing to develop a relationship with a “strategic partners”, rather than a production-ready model. The “Mubea” name is a conglomeration of Muhr and Bender, and they are a very large European producer of automotive components.
Carbon Fiber and other delights
One way that this company is trying to distinguish themselves is to make sure every visible part on the ebike that CAN be made from carbon fiber, IS definitely made from carbon fiber.
The reason this ebike is interesting is that the literature indicates the gearbox is located by the motor (instead of the rear wheel, like an IGH), which is a mid drive system. In theory, doing this reduces the unsprung weight in the wheel, which should make the suspension much more responsive during rapid-fire off-road maneuvers and jumps.
So…are there any pics of the gearbox? The Mubea instagram account seems to indicate that the gearbox is from Effigear in France. Do I know this for certain? No. But it makes sense that a big company like Mubea would assemble several existing components with high-end features to get some green buzz, and Eurobike would provide them with a LOT of free publicity.
Let’s take a look at Effigear to see what they are up to. There is a similar system by Pinion, which locates a geared transmission in the bottom-bracket area, to make the rear wheel as light as possible.
The Effigear uses a well-understood system where all of the input gears and all of the output gears are always meshing all the time. The way that a gear-pair is selected is by using a sliding “dog” that connects that gear-pair to the splined shaft. The high gears are always spinning fast, and the low gears are always spinning slow, but…only one gear-pair is attached to the shaft.
If you have seen the internals of an IGH, you might already understand how that would work.
Gears like this might produce some noise at higher speeds, but running them in an enclosed housing with an oil-bath means they will stay clean and lubricated during the dirtiest rides.
I don’t want to downplay the good parts of this new prototype from Mubea (it is genuinely well-done and impressive), but…a similar system was patented by Neox from Italy (the F8.18, seen below).
Written by Ron/spinningmagnets, August 2018