Motorsport R100RS a good idea?

I have the opportunity to pick up an unofficially-imported Euro R100RS
in the US. It's a '78 with ~80K km showing. Clean, fresh paint
(including Motorsport striping), Krauser bags, mud flaps. Not sure if
I really want to live with an Airhead, but I'm looking for opinions of
those who know them better. Known weaknesses? Issues to look for?
Should I just stick with Bimmers (I have E28s)?

A Motorsport RS is a somewhat rare and desirable motorcycle. If the
price is fair, grab it. You'll never lose money on it.

We're talking ~$3500.

That is probably a reasonable price for this rare motorcycle, even with
the non-standard paint. Why not make an offer of a bit less, stating
that as the reason?

I would, but this isn't exactly an arm's-length transaction. The owner
is an old pal who lives 600 miles away. He remembered *after nearly 20
years* (and a good 15 years of no contact most recently) that he'd
promised me first refusal on it and he dug up my email address to let
me know. I'm not screwing around with him over a couple hundred bucks.

Ok then. Not a good idea to screw over a friend.

There are a number of owner web pages, such as:

I'm discovering that.

Is the 'clean fresh paint' original factory paint?

Unfortunately, no. But in close photos, it's very nice. Stripes are
painted and clearcoated so there's no detectable ridge. There are a

Actually the factory pinstriping never did have clearcoat on top.

You do feel a ridge where the stripes are.

I kind of assumed that. In fact, I would not have been surprised to
learn that it was tape instead of paint.

I was simply describing what it has now. There is no pretense that it
is original paint but, if you're going to have a repaint on something,
it might as well look at least as good, or better than, original,
right?

few minor trim parts not yet back on (like the rear roundel).

All pinstripes in that era were on top of the paint, as Jim said.

There were a number of Euro models brought to the states legally, the
40mm '78 red and black R100RS Belgian police bikes for example. There

was also a batch of 2-300 leftover Australian police S models, that were
white with Motorsport pinstriping. (All real police gear was removed
from these of course.)

My understanding is that this one was privately imported by its owner -
who left it here when he returned to Europe, so it doesn't really fit
into any of the usual categories of 'batches' of bikes. Any idea how
many total white Motorsport bikes were built?

"US: 200 Non-US: very few"

Ah, so it's like the North-America only 535is I drive! In Europe, the
equivalent car was the M535i, but for some reason, they didn't want us
ign'r'nt 'merkins to have it - so we got a 'different' model.

The same thing happened with other models as well. My 77 RS is serial
number ...40 of the US series, and only the first 450 had the 40mm
engine. After that, they were 38's and had "CFO" stamped in the case
near the oil filler. California, Florida, Oregon - or so I understand.

You have my sympathies. Does your driveway still have the rust stains?

Naw, it did alright. We had it about four years, then traded it and
another car on a new Saab. ;-)

=3D8^O

I have a 1977 R100RS in the matte silver, bought new and still in the
garage, though I don't ride it much anymore.

Thanks for all the help, folks! It's looking like I may become an
Airhead Guy=A9 soon.

I'd go for it. Apart from being a little elderly they don't have
many weaknesses.

The alternator rotor has been known to fail (~$100 to replace)
and the clutch splines should be lubed once a year or so. It's
a points ignition and that'd need some occasional maintenance.
Valves need adjustment every 10k or so and the seats might
need rework for unleaded U.S. gasoline if they haven't had it
already. Brakes would probably be OK but not spectacular.

They're basically a pretty robust bike with a wide network of owners
and good parts availability.

I have put 170,000 miles on my R/100/7 bought new in '78.
Over the years I've basically converted it to an RS, the only
differences left is the taller gearing of the stock RS and rear
disc. There wasn't much difference to begin with, bigger Bings,
valves, maybe compression, fairing, rear seat cowling, handlebars.

I've done very little actual repair work in those years, very
few parts wear out, they were built for the long haul. Of
course, these days a 600cc bike will blow it's mirrors off
but that's besides the point. They handle well if you don't
push them too hard, the suspension soaks up road
irregularities that's top notch by today's standards.

The brakes are a weak point, I put a '81-'84 front end

In '78 they had yet to abandon the under-tank master cylinder, which
is cable-actuated. Yeah, it's a nightmare in a number of planes.\

The iron castings are prone to pitting and they can only be honed so
many times before a new re-build piston will last less than a year.
After that it slowly pumps the brake fluid out and the red light for
the float switch (float switch!!) tells you to re-fill the master
cylinder so it can continue to drip over the electrics and the frame
brace underneath.

Anyone foolhardy enough to want to retain the 'performance' of the
stock m/c setup is wise to: a) install the rubber boot upside down,
so the weep hole is *up*, and stuff the boot with a diaper made of
paper towels, and b) bore the m/c up and sleeve it with a piece of
brass tubing. Once that's done the piston seals will last indefinitely.

Other bugs: The centerstand mounting points are thin and weak. If the
bolts holding the stand are allowed to slack off, the threads in the
mounts will strip and this requires removing the entire exhaust system
to helicoil.

Put a good fork brace on, you can dispense with the hydraulic steering
damper which tends to wear out after about 50K miles.

Diode board, oil filter O-rings, valve cover stud pullout, etc.

on mine for the newer Brembos and setup and it still leaves
much to be desired compared to modern brakes. There's
probably better solutions, I'm still working on it. But like
someone else said there is a large knowlegable network of
airhead loyalists, much of it online.

I'd get it. They have a ton of personality and they're pretty easy to
live with. Fun to work on too (when you have to). If you have basic
wrenching skills, anyone can keep an airhead running forever. I like to
wrench 'em more than the oilheads and MUCH more than the "K" bikes.