I'll be looking at a BMW RS100 this pm, possibly buy.
Has 94000ks (about 56500 miles). 1982. Some wear in final drive,
'clunk' when taking off from standstilll. Fairly common I think?
Anybody had/own one of these? Anything I should look for in
particular? Any traps? Have had bikes before but this will be the
first BMW. Has Brembo brakes and ss exhaust. Tia for any comments.
Ive got a R90/6, '75 model. It has 187,000 miles on it.
The clunk is pretty common for Beamers. Its the nature of the beast
and may not be final drive wear, particularly with that few miles on
it. At 56,000 unless the previous owner was a kid knee dragger
(unlikely with that particular ride), its just broke in.
Just be aware..that older Boxer rear brakes are....a bit...inadequate,
if you have the rear drum.
Put it up on the centerstand, pull the rear wheel and check the final
drive "lovejoy" couplers. The gizmo that connects the rear wheel and
the final drive. They are replaceable, but spendy if they are badly
worn, which they shouldnt be at that mileage. YMMV
Also drive shaft spline, when you have the time.
You will want to either bookmark or print out this site
Also, check the 'gaiters" on the front forks. If they are cracked or
broken, they WILL need to be replaced. (gaiters are the accordian
rubber tubing covering the front fork sliding sections.
Oh..the boxers of that vintage have a surprising amount of kneel..when
you cram on the front brakes, they tend to lean far forwards..makes
you feel like you are about to do a summersault. But if the previous
owner put Bembo brakes on it, he may have modified the suspension.
Ive not had mine on the road since 98. No time, no money. But I fire
it up every 6 months and run it till it warms up, and change the oil
once a year. Someday when Im rich and famous, Ill change out the
point style ignition and put in an electronic one. Shrug
"That which does not kill you,
has made a huge tactical error"
Can't tell you anything about the RS 100 but... When I got out of the
Navy, I bought a used 1965 R60 from a BMW dealer. He said it would be the last
motorcycle I would ever really need. 35 years later, I still have it.
Agreed - about the idea they're probably not badly worn at 50-something.
But harder to replace than you think, it means a new spline
coupling on the wheel, *and* either a new ring gear (the male
spline on that is integral) or a re-work of the existing worn
spline. Some folks glop braze on the worn spline, and then
remachine the splines. THis supposedly gives 75% wear life
from that point on, compared with the original. I'm not
sure I believe that.
My R75/6 is high miles and has a fairly worn rear drive coupling.
When it gets critical I plan on begging the wire EDM guy here
at work to make me a new male spline out of steel, and then
machining the old one off, and silver-soldering the replacement
A bike of this vintage probably has no gaiters. If he buys it I
would suggest he fit them.
This is the 'gummikahw' effect. Fitting slightly heavier (7wt)
fork oil, and a set of progressive springs, will help on this one.
The real trick is a fork brace, this makes an amazing improvement.
You can put a Dyna III in there, but if you want my personal advice - leave
'59 R50 (ready for powder coating)
Thanks Gunner and Vaughan, (only replies I've seen so far) Gunner,
those sites were exactly the sort of thing I need. Had heaps of bikes
but know bugger all about BMs. I bought the bike. Rear disk. Bit
rough appearance wise but seems mechanically sound. The mechanic that
put me on to it knew the bike and told me it was good. The ex-owner
seemed like a straight shooter. Has the two panniers and top box.
Stainless exhaust. Always wanted a BMW. Paid $Aus4000, which seemed
quite reasonable after checking mags etc. I like it! All in all, a
good day. Thanks again. Some blokes, when having a mid life crisis
get the blonde and Porsche, me, I get the bike and me knee fixed! :-)
See ya, Mac.
Thanks again for the info, as you see from previous post, I bought it.
It does have the fork brace. I'll generally be riding it on open road
and am a fairly sedate rider, but you never know, have been known to
get a rush of blood to the head! :-) See ya Mac.
>>Put it up on the centerstand, pull the rear wheel and check the final
>>drive "lovejoy" couplers. The gizmo that connects the rear wheel and
>>the final drive. They are replaceable, but spendy if they are badly
>>worn, which they shouldnt be at that mileage. YMMV
>Agreed - about the idea they're probably not badly worn at 50-something. >
>But harder to replace than you think, it means a new spline
>coupling on the wheel, *and* either a new ring gear (the male
>spline on that is integral) or a re-work of the existing worn
>spline. Some folks glop braze on the worn spline, and then
>remachine the splines. THis supposedly gives 75% wear life
>from that point on, compared with the original. I'm not
>sure I believe that.
>My R75/6 is high miles and has a fairly worn rear drive coupling.
>When it gets critical I plan on begging the wire EDM guy here
>at work to make me a new male spline out of steel, and then
>machining the old one off, and silver-soldering the replacement
>>Also, check the 'gaiters" on the front forks. If they are cracked or
>>broken, they WILL need to be replaced. (gaiters are the accordian
>>rubber tubing covering the front fork sliding sections.
>A bike of this vintage probably has no gaiters. If he buys it I
>would suggest he fit them.
>>>Oh..the boxers of that vintage have a surprising amount of kneel..when
>>you cram on the front brakes, they tend to lean far forwards..makes
>>you feel like you are about to do a summersault. But if the previous
>>owner put Bembo brakes on it, he may have modified the suspension. >
>This is the 'gummikahw' effect. Fitting slightly heavier (7wt)
>fork oil, and a set of progressive springs, will help on this one.
>The real trick is a fork brace, this makes an amazing improvement. >
>>Ive not had mine on the road since 98. No time, no money. But I fire
>>it up every 6 months and run it till it warms up, and change the oil
>>once a year. Someday when Im rich and famous, Ill change out the
>>point style ignition and put in an electronic one. Shrug
>You can put a Dyna III in there, but if you want my personal advice - leave
>'59 R50 (ready for powder coating)
Very fair price. The rear disk is fair. The front duals are
pretty good. As suggested, do the increase in fork oil viscosity
and progressive springs if this has not already been done. The
fork brace's existence implies it has, however.
If this bike has the front master cylinder under the tank, it will
be weepy because of the rough casting, and should be sleeved with
brass at some point. If the m/c is on the bars, then that's good.
The charging systems are good but not very good. 280 watts is the
limit. Get a good manual for maintenence. The stainless headers
and mufflers are a nice touch. Those are worth over 500 by themselves.
Keep oil in it, keep some valve clearance in the valves. Put some
inline filters in the fuel lines to keep away that 'wet shoe'
Things that go wrong:
Rear main seal can get weepy
Driveshaft boot can get weepy
Instrument cluster lights are troublesome, so's the housing
You're good to ride for over 100K miles.
My '77 BMW R100/7 had that clunk. I'm not aware that it was a problem,
just "one of those things".
Ask specifically about carb synchronization if this is the 1000cc
boxer engine with bing carbs that I'm thinking. If the owner gives
you a vacant stare, then be aware that it's probably not performing
up to potential. Unless it changed dramatically between '77 and '82
(I have no idea, sorry), there's not a lot to go wrong. Bosch
electricals common to any european car of the era, and so on.
It's well built and designed. I didn't have much experience fixing
mine because it didn't break.
Not really. The bing cv's are actually pretty easy to synch,
and they hold their settings for a long time. The only major
known carb bug is a) the CV diaphragms hole after many years (easy
fix) and b) if there's no filter upstream of each carb, the
float needle will hang open and give one gasoline-soaked footwear.
It's been a while, so I can't picture that model. I remember R100S
(small fairing), and the R100RS (larger fairing with lowers). I had
the latter, it was either the first or second year of production. Only
major problems I remember were warped front brake rotors (they were
pretty thin), and broken gear dogs (third perhaps). Both should have
been well cured by '82. I also remember lots of fork stiction, which
the factory said could be alleviated somewhat by removing one of the
two seals in each leg , which pretty well finished off my
impression of the "finely engineered" thing. I did like the light
weight and big fuel tank. I took it on a 5000 mile trip once without
problems, and I'll give the seat nine stars.... out of a hundred. ;-)
Boxers..and boxer owners tend to be something of an unusual bunch.
You have the snooty techno riders, who have to have the latest and
greatest high tech shit, expensive custom leathers and look like
something out of the 22nd century.
Then you have the rest of us. Personally, I like SOME boxers (not K
bikes) simply because they are dependable rides that are comfortable
over long distances. Wash and detail one? Thats what putty knives
are for, once a year, if you cant see the headlight anymore. Or if you
got coyote/rabbit guts deeply into the cooling fins of the head(s) and
the smell makes you hungry.
I actually had ants swarming my bike once. But that was cool as they
only ate the rabbit guts. Saved me from having to use a pressure
washer to get Thumper off the engine.
Beemers make great rat bikes. Though they do tend to be tough on rear
tires as they seem to wear faster than on any other bike Ive owned.
Oh..and clutch lever adjustment...something Jim might give you a heads
"That which does not kill you,
has made a huge tactical error"
First off you don't get them for free, I think a dyna 3 is a few
I have a points ignition in my R75, and the new bike had that
same setup but was retrofitted by the previous owner with the
When he did it, he hooked the electronics box up wrong to the
coils, but it did still run fine.
Comparison shows that both points and the electronic ignition
do indeed provide satisfactory spark to run the bike. Granted
I've removed the stock BMW wires and resistor plug caps on them,
and replaced with straight copper 8mm silicone rubber wires
from Taylor Vertex. So the resistor issue is moot.
The think I like about the points is they seem to not require
adjustment on that bike hardly at all. I haven't had the
front cover off the R75 in about two years, so there's not
a lot of tinkering required.
The Dnya 3 uses the stock mechanical ignition advance unit,
so whatever unreliability is inherent in that, is still present.
And the dnya trigger unit that attaches to the cam seems a bit
fidgity, though I've had no troubles with it. Likewise the
circuit boards that hold the pickups seem kinda fragile.
The one upside with the Dyna is, I think you can individually
move the pickups to get the spark spot on on both jugs. But then,
my R75 never had the 'split timing marks' problem.
I think for me the biggest worry is that if something goes wrong
inside the potted electronics unit, it's a drop-dead, walk home
failure. With points, you can always manage to get 'em working
somehow. Of course I carry spare points and condenser in the older
bike's toolkit. I know that folks say that electronic parts
are so much more reliable than mechanical ones - but this is
a vehicle, and the parts are a) built to a price, using b) consumer
grade parts, and d) subjected to extremes of temperature and
I'm either going to start carrying an entire spare dyna unit, or
swap back to points on the newer bike.
Well, that's what I'm saying. If they haven't done it, then there
is a huge potential for vast improvements in performance by doing
it. If they answer "Yeah, it's a snap, buy a polysynch if you
don't have one", then that tells you more about the seller and how
they may have kept the bike up.
Maybe the one I bought was more fscked up than normal, but they were
_way_ out of tune with each other when I got it. Then again, the clutch
was out of adjustment (no free play - 30 second fix), the oil was
chunky, the voltage regulator was shot, and one fork was nearly dry.
Guy figured the bike was ready to part out, when it just needed about
an hour of attention (and a voltage regulator from one of my parts Saabs).
I like to just short first one, and then the other, plug to
ground. If the sync is right the idle will not change speed
at all when this is done. I've found that setting the idle
air screw on those carbs seems to be done best with *both*
carbs running, unlike the bikes I have with direct slide
Those are good buys - the bike I bought had the headlight installed
upside down. The seller made the comment "I don't like those H4 headlights
very much, they don't seem to work very well...."
Thanks Jim, it has the front master cylinder on the
right bar, has inline fuel filters and he threw in a 'Haynes' manual
which seems pretty good. He said he changed engine oil and filter,
gearbox oil, drive shaft oil and diff oil every 10000 kms (about 6000
miles) Changed the lot! See no reason to dis-believe him, he seemed
the type. It just gets better! :-) Regards, Mac.
Thanks Dave, the ex-owner volunteered information
about the carbys, said easiest way to check was to run on stand to
about 3000rpm, pull a plug lead, note rpm drop, replace, pull other
plug lead and compare rpm drop and should give indication of how
carbies performing. Sounds sort of logical and this bloke maintained
it pretty well. Bit like mag check on a/c!
I haven't had much to do with the Airhead beemers - I have a K100RS
(inline flat 4)
The Internet has lots of resources for them. There are also a lot of
places selling parts online. I have found
to be good. They are generally 30% cheaper than
here (New Zealand) and delivery is much the same as getting parts
through the official channels from BMW. One example - fork stanchion
(gen BMW) for my K - 179euro from Siebenrock, 440euro from BMW NZ and
would have to be ordered in - same part, both brand new. What is the
value in local support there with that markup?
may be of use:
(although for a later model than
fiche for most BMWs
another parts fiche (incld cars)
Discount Motorcycle Wreckers, 35 Dawson St, North Coburg, Melbourne,
Phone 03 9350 4417 specialise in wrecking BMWs
Yeeeahhhhh...I can see how an H4 upside-down would be unpleasant. For
him, _and_ for passing airplanes. The one I bought was from a cow-orker,
so I couldn't gloat _too_ much about it. I just told him that I spent
some quality time with the bike for a week. Didn't mention that it
totalled a couple hours.
He also didn't know about the hinged oil filter, so the fairing was
making oil changes a major ordeal. Wasn't a mechanic type guy. Good at
tuning MRI scanners, though...