[rodhotter]

a left side exhaust is better for a "rig" sidecar thats in the USA of course. it would be a small market + of course be $$$$ but a factory rig would be great IMO!

 

[masseesj]

I'm just curious: Anyone know why BMW changed the final drive position from the right side for the previous 1150 and 1200 platforms to the left side for the new 1250 (and, of course, the flip of exhaust side followed suit)? Was there some expressed benefit/improvement in performance from the change, or was it just necessitated by some factor related to the new Shift-Cam design?

My 2016 R1200RS has left side drive and right side muffler.

 

[Turtl]

Interesting, thanks. With both in mind, sounds like it could then be a mix of aesthetics and engineering.

I think it was more about engineering than aesthetics. The Wasser 1200 was when the change of drive shaft from right to left was first introduced and it has been kept that way on the 1250. I believe it was all related to the way the engine was redesigned to incorporate the introduction of water cooling requirements - changing the way the engine was configured.

 

[Mr. Badger]

The primary reason for rotating the airflow to perpendicular to the crankshaft is simplifying the cam drive for a modern 4V head and valve train.

 

[Moderately Excessive]

I think possibly the main advantage of the vertical 'intake over exhaust' configuration is simply that the air gets a much straighter shot at the engine, avoiding the longer 'S' bend of the older layouts...

But what do I know? I just like to ride the damn things!

🏍

 

[Panzermann]

The primary reason for rotating the airflow to perpendicular to the crankshaft is simplifying the cam drive for a modern 4V head and valve train.

Could you not achieve the traditional fore/aft exhaust/inlet configuration by simply having an inlet and exhaust lobe on each camshaft (rather than two inlets on one, two exhaust on the other)? Of course timing chain routing would be tricky. And why would you, anyway.