So we come to the bike you see here – the
R100GS. In fact, this one is a GS-PD. Note
the GS loses the slash of the G/S, perhaps in
recognition of the softening of the gelande
aspect. While, contrarily, PD stands for Paris-
Dakar in reference to the firm’s rally successes.
One of the bigger changes for the 1989 model
was the Paralever rear suspension, there for a
more comfortable ride. Designed to ‘decouple’
the rear wheel swingarm from the drive and
accelerative forces, the trapezoidal geometry
of shaft drive housing and torque arm were
nothing new to BMW (having appeared on its
road racers of 1955), but the result was a
smoother drive train without the associated
lift and squat associated with the direct shaft
drive of before.
The forks were also upgraded, from 36mm
units of BMW’s own making to Marzocchi 40mm
units with special conical bushings to take big
hits (this despite the bike being more road
oriented) and a 25mm hollow axle to add
rigidity. The frame was braced and a stronger
subframe added. More significantly, from a
safety perspective, BMW developed a new
design of spoked wheel where the spokes were
laced to the outside of the rim, allowing for the
fitment of tubeless tyres. The rear wheel was
changed from the off-road norm of 18-inch to
the emerging road bike standard of 17-inch
(with four-stud coupling to the shaft drive –
previously three-stud).
The motor, now taken from the R100RS, had
grown to 980cc to produce 60bhp. The extra
oomph was needed as weight had increased
by 15kg too.
The PD version started life as an optional
accessory kit (the standard GS being a naked
bike with a smaller tank and small fly screen)
but by 1989 there was a specific PD spec with
the signature 32-litre tank and touring fairing.
KIWI RIDER 59