Inside a Brose Drive S

[Rob Rides EMTB]

 

[Mike Smith]

Interesting to see Rob

 

[wrayb]

Build in an 8 (10? 16? 3? who knows) speed transmission (a.k.a. internal hub gearing)...eliminating the need for a derailleur and cassette and now you have what all Emtbs need...

 

[steve_sordy]

So it's a toothed belt!

That's one question answered then.

 

[Pukmeister]

A pretty slack one at that !

 

[Mikerb]

A pretty slack one at that !

There will be a belt tensioner....probably in the bottom half of the casing which is not shown on the pics.

 

[Mikerb]

What you can see is the use of a planetary gearset with helical teeth....a design that deliver speed reduction on the carrier and is both high torque and quiet. The carrier is connected to the output shaft which is in turn connected to the crankshaft via a toothed belt. Unfortunately about the only things you can see in terms of detail on the crankshaft is the cadence sensor ring (looks like a bracelet) and a bearing. It does not give any clues about the freehub type but my guess is that it is a pall mechanism as it seems completely encased and a meshed gear would need to be steel and need an oil bath. A pretty expensive and concise piece of engineering.