Quote Originally Posted by euphonius View Post
Do you understand BMW's logic for using the same 798cc engine in both the F800 and F650? Perhaps a different crankshaft with a shorter throw so the 650 displaces a smaller volume? Why bother offering an F650 twin if it's really an 800?
There is a lot of confusion about BMW's naming convention and I personally haven't yet found any reasonable explanation.
The engines installed in all 798cc bikes, the F650GS (from 2008) as well as the F800 GS, ST, R, S, are the same, obviously only cam-shafts and software make them different.
F650GS: 52 kW (71 hp) at 7,000 rpm (output reduction to 25 kW (34 hp) at 5,000 rpm possible)
F800GS: 63 kW (85 hp) at 7,500 rpm
F800ST: 62.5 kW (85 hp) at 8,000 rpm (output reduction to 25 kW (34 hp) at 7,000 rpm possible)
F800R: 64 kW (87 hp) at 8,000 rpm (output reduction 25 kW (34 hp) at 6,000 rpm possible
F800S: 62.5 kW (85 hp) at 8,000 rpm (output reduction to 25 kW (34 hp) at 7,000 rpm possible)

The output reduction is useful in some markets where new riders are facing power and power/weight ratio limitations.

Still, the name 650 is weird, confusing, strange, a myth, ...