What's the function for the shaft "pinion" ????

[Gerard]

So far nobody could answer that question, even at the dealership...

Anybody has an idea ?

Air cooling the shaft ??

This structure might be source of trouble, like catching some clothes or a scarf in it .

 

[enzo5000]

I'm sure it is just a styling effect and it looks cool spinning in the sun.

 

[Gerard]

Could be.
But they had to machine it !

 

[TodkaVonic]

The prototype doesn’t have those fins on the shaft. I’m guessing they’re decorative.

 

[Gerard]

Also looks comparable to the anti-theft system allowing to lock the shaft they were thinking about, at one moment.
But it was at the other end of it.

Upcoming BMW R1800 Will Get An Ingenious Anti-theft System

Leaked patent images showcase several versions of the mechanism

www.outlookindia.com

 

[TodkaVonic]

I honestly bet it looks as it does, as opposed to a simple, nickel-plated shaft, to emphasize it’s rotation and thus leave no doubt that it IS the shaft itself and not a decorative cover. I know, there’s a huge knuckle of a tripod joint spinning just aft of it. Still, given the my amount of engineering which went into it, probably not a bad idea

[from motorcycle news]

For the R18, BMW have thrown away 40 years of driveshaft tech and started again. To create the classic look of the R18, BMW have fitted a cantilevered rear-end. That means the entire rear-end is fixed, as if like a hardtail, and it pivots around one point at the bottom of the frame – at the top of the cantilever is a rear shock providing 90mm of travel.

"This looks beautiful and classic like the R5," says Sepp Miritsch, Head of Air-Cooled Boxer Series. "However, the knock-on effect of the offset pivot points means that the driveshaft needs to be shorter as the wheel moves through its arc. To get around this we have used a tripod joint – a motorcycle first."

A tripod joint uses a three-pronged yoke attached to the gearbox output shaft with roller bearings on the end. As the suspension compresses and the wheel arcs upwards, the yoke spins at a constant velocity while bearings run in groves in the driveshaft, allowing the yoke to plunge down inside the driveshaft housing.

This enables the driveshaft to automatically adjust its length without any loss of power. The cantilever effect of the rear end also prevents any shaft jacking – clever stuff, eh?

[end quote]

 

[Black Dog]

So far nobody could answer that question, even at the dealership...

Anybody has an idea ?

Air cooling the shaft ??

This structure might be source of trouble, like catching some clothes or a scarf in it .

View attachment 487

Like tits on a bore hog. No actual function, they are just there to attract.

 

[theMucker]

A salesman at my dealership also mentioned the "teeth" as a potential that might grab clothing. The potential as a hazard seems very remote to me. And I think that BMW put them there for visual effect.