VOL. 56 ISSUE 16 APRIL 23, 2019 P59
by 400 revs to 14,600 rpm, with a com-
mensurate rise in peak power while running
a 13.3:1 compression ratio. And the offset
chain drive to the twin overhead camshafts
is now driven directly off the crank: the
previous idler gear is no longer needed.
Revised porting for the 16-valve DOHC
engine's inlet ducts, coupled with a new
stainless steel exhaust system that's 1.3kg
lighter with twin three-way catalysts, dual
lambda sensors before and after the
catalyst, and an electronic power valve,
all contribute to the new bike's increased
overall performance even in Euro 4 com-
pliant street-legal guise. And as before,
the new RR engine is also fitted with a
variable-length intake system whereby the
length of the inlet funnels atop the 48mm
(Left) All of the
'19 S 1000 RR
variations see
a minimum
11-pound weight
loss. (Below)
The S 1000 RR
offers four RBW
riding modes as
standard with
optional Pro
Modes, including
three additional
configurable
modes for
optimum
individual
adaptation to
conditions.
throttle bodies is shortened via
an electric motor at 9500 rpm
to enhance top end perfor-
mance in conjunction with the
ShiftCam Technology system.
Moreover, the throttle linkage
operating the four butterflies
is split into two, with the two
left-hand throttle bodies oper-
ated separately than the two
right-hand ones. This allows
BMW race teams to program
the two pairs to work indepen-
dently at lower rpm to give the
same benefits as a twin-cylinder
motor in terms of traction and
drive exciting a turn, before all
four resume working in unison
at higher revs.
This feature results from
BMW deciding not to pro-
duce a big-bang Yamaha
R1-type cross-plane-crank
motor, but instead to employ
its decade-long experience
of a more traditional 180ยบ
'screamer' motor in building a
better such design. "We did
consider a big-bang design at
the very outset," says S 1000
RR project engineer Michael
Thewke, who's anchored the
whole project every step of the
way over the past four years
of development, "and we also
briefly considered building a
V4. But we decided against
both of these early on, not only
because we didn't want to be
seen to copy anyone else, but
also because we had so much
experience especially from
Superbike and endurance
racing in developing the more
traditional-type four-cylinder
