K series

[ukzknos]

Blasphemy!

I know but......the R65 is a great commuter/short trip bike but it is fairly tiresome after a hour on the motorway at 80mph (that's assuming you can cope with the vibration).

Has anyone got, had or have a view on K75 or K100's?

Steve

[Rob Valdez 79 R65]

I've always leaned toward the K75, especially in 'S' form!

[Bengt_Phorqs]

Had an '85 K100RT for several years.  Amazing torque and would do the ton almost at will and was still fairly smooth.  Roomy enough for two up travel and good weather protection.  Fuel mileage was only around 35mpg or and I don't have a heavy throttle hand.  With the longer wheel base it liked to go through the curves in a swoopy fashion rather than crisply.  Not bad if you knew how to approach it.  Brakes were good with twins up front and a single in the rear.

Downsides were that the weather protection was too good.  It's a really hot bike to ride when the temp exceeds 85F.  The heat just rolls off onto your feet.  I'm not a big fan of water cooling on bikes because that's just one more item to service.  The early K bikes were noted for having faulty fuel gauges.  They will read low when the tank is only half full.  The tranny always felt like it needed one more gear although it didn't.  But then it was a smooth shifting tranny.  Getting to the electrics under the seat was a real PIA.  Check out the tech section on IBMWR.org.  There are some good topics on the K's.

In summary, they are good bikes, well designed and quite reliable.  Mostly.  But they do have some quirks and once you know and understand them they are OK.  I eventuallly sold it because I'm more of a boxer/airhead kind of guy.  Let us know what you do.

[nhmaf]

I tried out several K100RS bikes - and agree with Mike (Phorqs) assessment.   They really are solid, but also rather top heavy feeling.
The K100 bikes do have a tendency to emit a higher frequency buzz in the handlebars and somewhat through the tank/footpegs at times.   Keeping the injection system properly synched helps a bit with that.
They will "cook" you if you are stuck in slow traffic on a hot day.  

The K75 bikes are definitely smoother runners (no buzz) and, while they don't have the 100 HP (on this side of the pond, anyhow) that the K100 bikes do, they manage very nicely with the ~80 HP they put out.  They do tend to have a high pitched "turbine/jet engine" type sound - which some people hate and some love.   This sound is largely due to the counterbalancing system which keeps things so smooth.   I know of several people who love their K75 bikes and rack up many miles on them.  For some reason, they've all had issues at some point or another with the rear shock breaking on them (literally, breaking).   My cousin owns a 1985 K100RS - has owned it since new, and has somewhere around 175K miles on it.   He has had to replace the transmission and overhaul the final drive once or possible twice in that period, and he typically rides on trips that are a few thousand miles at a shot.   He would never give up that bike, either.

[MrRiden]

Been contemplating a K75 myself for a more modern highway bike. There seems to be plenty of examples out there going for cheap. Most I have seen seem to be neglected which is right up my alley.

[mimmo66]

I use the K75c for long trips only and when the weather is not too hot!

It has a good power and it will keep high speeds all day long, a bit on the thirsty side, top heavy, not as much fun on the twisties as the r65.

Less maintenance needed than an airhead per ridden miles, although more labor intensive. Plan on installing progressive fork springs as the stock ones dive way too much.

Lubing the transmission splines on regular basis is mandatory on these bikes.

Other than that is a great tourer bike!

Dom
1981 r65ls
1985 K75c

[montmil]

You're in luck, Steve. Here are a few K-series articles from Motorcycle Classics, the US-published kinda version of England's The Classic MotorCycle magazine... the Blue 'un.

http://www.motorcycleclassics.com/search.aspx?search=BMW%20K75

Monte

[ambrose78]

K's look great when cafe'd

[Crossrodes]

I had a K1100LT.  Wish I still had it.  It was a great bike for the highway with great wind protection from the electric windshield.  I too would like to get a nice K75.

[ukzknos]

Well I've gone and done it!

A 1993 K75, 30,000 genuine miles, ABS, BMW hard panniers (one slight paint blemish on the tank!) all for a bargain GBP£ 1250 and, I have to say I'm very impressed

Not quite the character of the R65 but one smooth motor which will fit the bill nicely for distance touring.

The question is what to do with more than one bike cos you can only ride one at a time?

Steve

[Yikes]

OK, Steve, congrats on the new bike!  Sounds like you got a really good deal.  Now how about a pic or 2?

[Ed Miller]

"The question is what to do with more than one bike cos you can only ride one at a time?"

I usually seem to be working on the one I'm not riding.  Maybe I need something modern.  Anything, even a lawn tractor.  My John Deere was made in 1968.  I don't know what's wrong with me.  

[bjamesw]

I saw K  bike for sale on the roadside yesterday and was wondering exactly the same thing.  I was trying to imagine how it might look totally 'naked' to highlight the unusual engine a bit more.  

I know it's been brought up here before, but I ought to repeat it.  My '82 R65 has a really tiny amount of vibration at between 4200 and 4500 rpm, but below and above that all the way to redline it's glass smooth;  in fact as smooth over 4500 rpm as any other bike I've ridden regardless of size.  It was a little rough when I bought it in 1992, but over the years I've gotten pretty good at tuning it.   You might want to check on the possibility of clutch balance (improper installation), wheel balance, valve settings, or carb sync being less than ideal.

[jusgus]

Last month I rode up to NC & Tenn with my brother Jim.  He was on his K75.  In the mornings she wouldn't start.  Jim thinks it is in the computer (1of2) and temp related.  The result was that after camping on Mt Mitchell ol' Kay White wouldn't start til after lunch.  No way to get her to start , no current to the coils.  We cut the trip short when she did start.
I prefer a machine that is more simple, like me.

[suecanada]

The computer under the seat, Gus, caused my brother some head scratching too. He tested the temperature issue by putting it in the freezer to cool it as it would be in the mornings, then used a hair dryer to heat it up and then try it. Faster than trying each morning when it's cold and getting a short term case of Torettes syndrome!

Seems to help zero in on the problem. Hope it helps!