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K75rt/k100rt

georgej

Member
Anyone with a K75RT or K100RT what made you choose the K over an Airhead RT? Specifically an R80 or R100 Monoshock bike.
 
Anyone with a K75RT or K100RT what made you choose the K over an Airhead RT? Specifically an R80 or R100 Monoshock bike.

K75RT: Engine power. Fuel injection. Better suspension. Less frame flex. Water cooling. Smoother. Better wind protection. Electric adjustable windshield. Designed in the 1980s instead of the 1960s. No valve recession. Doesn't burn oil. That is my short list. Others may not agree.;)
 
Anyone with a K75RT or K100RT what made you choose the K over an Airhead RT? Specifically an R80 or R100 Monoshock bike.

I have now, and have had, a number of both classic K-bikes and Airheads, among them an R75/5, R65, two R100RSs, a K100RT, K75S, K75C, K1, and a K1200RS. The K100RT was my first classic K-bike that I bought in 2000. I like and appreciate both series, but for me, the K's offer a *much* higher ratio of riding to wrenching. The engine only rarely requires a valve adjustment - you check them every 20,000 to 30,000 miles and typically they are fine - and it's easy to do. Run quality fuel and the occasional dose of Techron and the fuel system is stone reliable requiring only very infrequent air bleed adjustment. No mixture settings or throttle body (carb) balancing ever. Air filters will last up to 40,000 miles in good conditions. Oil filter changes are not as fiddly as an Aihead with it's side mounted filter. Transmissions are very strong and last a very, very long time (no missing circlip like on some Airheads). Excellent frame design with the engine and transmission as stressed members, they will ride and handle well just with good OEM grade tires and suspension, but put a bit of work into the forks, get a good shock, EBC-level brake pads, top end tires, etc, and they will run away from even a mono-shock Airhead (which IMHO is the best handling of all the Airheads). Part of that is the better frame/suspension, and part is the much greater power (especially the K100). The K75 is legendary for it's engine smoothness and being an overall very well balanced bike.

They have their maintenance items as does any machine - especially you still need to lube the clutch splines like the Airheads. There is a crankcase breather hose that requires replacement every 40,000 miles or so, and many K75s or K100s could use the rubber bits holding the throttle bodies, the injector O-rings, and the fuel lines replaced due to age-related hardening. I always factor in a budget to get a used vehicle back into proper condition. But, once you do, the classic Ks will just run, and run, and run, and run. I really like that, and I like their stability on the road, secure handling, and the additional power over comparable age Airheads.

That's me. In the end, I think some bikes just speak to you and other's don't. Some give you a great big grin when you ride them, and others not so much. Get the bike that gives you the biggest grin factor, and I think you will always enjoy it.
 
I agree with what's been said here, they are totally different experiences. The K series are better motorcycles, and I have a nice k75, but I still prefer to ride an airhead. I guess it suits me better. Do you really have to choose, get one of each.:laugh
 
The K has a taller saddle and it's a little heavier but the power delivery makes it all worth it. The K75 delivers 75hp, 15 more than the R100. It's smooth and pulls through the whole power band. For a trouble free, low cost, dependable bike, the Ks would be my choice, particularly the K75's, and I've had bunches of airheads (still have two), K's (still have two) and an oilhead (still). Enjoy the ride.
 
I've got one of each too!
A 1978 R 80 with a luftmeister fairing and a 1990 K75 RT
The K is too hot for me when ambient temps rise over about 80-85f which is pretty low.
I still do 1 or 2 tours a year on my R 80, so retro. I like working on it; its got points and a Ted Porter Valve job, so its been very reliable. So simple.
The Lack of needed maintenance on the K series is amazing!
Nick
 
I have to add that first off, I'm much more and RS rider than an RT ride. However, my first K-bike was a 1988 K100RT, which was a great bike, but that fairing and all the heat sucked up off the engine behind it was a lot like a convention oven above 90 degrees. I just couldn't ride it in the peak of the hot season when 90 to 100+ temps are common. The K100RSs and K1100RSs are much better, as is the K75S. My K1200RS doesn't have a heat problem at all.
 
First time BMW buyer K vs R

Just joined MOA today.

I'm a long time Yamaha and Honda rider, street, tour and dirt. Just purchased a completely restored 1969 Yamaha DT1 250 (one of my first bikes) and just love looking at it. Can't believe what they cost!

I have the classic/collector bug now and want to buy a classic BMW thats a true rider. I've spent untold hours over the last month or so trying to determine what bike to buy. My first inclination is a K100RT or K75RT but I'm drawn to the R100RT as well. More "BMW" to me. I know whats going to happen, I'll end up with both with no where to put them! The older GS's are unbelievable as well and satisfies my past dirt/enduro days but at 60 years old I'm not sure how smart that would be...

I just bought Claudio Somazzi book BMW Mortorcycles of the Century. Great reference book but is missing so many of the models. Does anyone have a suggestion on what book I can buy to compliment this book?
 
Just joined MOA today.

I'm a long time Yamaha and Honda rider, street, tour and dirt. Just purchased a completely restored 1969 Yamaha DT1 250 (one of my first bikes) and just love looking at it. Can't believe what they cost!

I have the classic/collector bug now and want to buy a classic BMW thats a true rider. I've spent untold hours over the last month or so trying to determine what bike to buy. My first inclination is a K100RT or K75RT but I'm drawn to the R100RT as well. More "BMW" to me. I know whats going to happen, I'll end up with both with no where to put them! The older GS's are unbelievable as well and satisfies my past dirt/enduro days but at 60 years old I'm not sure how smart that would be...

I just bought Claudio Somazzi book BMW Mortorcycles of the Century. Great reference book but is missing so many of the models. Does anyone have a suggestion on what book I can buy to compliment this book?

BMW Motorcycles by Holstrum and Nelson is a good one.
You may also want to post your questions under their own heading rather than tacking it on the end of another. It'll get you more visibility.
Also know that the K bikes, while loved by many (myself included) are somewhat the bastard child of the lineup. If you are considering collecting, and concerned with resale/appreciation, the boxers are a safer bet.
 
K vs R

The K doesn’t have opposed cylinders. I’ve got a K, a R and a S. The R1200S is my favorite. The K is for when I’m just running around town. The S is for when I want to go over 100 mph.
 
The K doesn’t have opposed cylinders. I’ve got a K, a R and a S. The R1200S is my favorite. The K is for when I’m just running around town. The S is for when I want to go over 100 mph.

:scratch I am not aware of a K bike that won't easily go well over 100mph.

Even the slowest Kbike, the K75RT is rated by BMW at 115. All the others are faster.
The brick K1200RS was rated at 154 mph.





:dance:dance:dance
 
I am a K bike guy to the core. When an R bike speaks to me it says "ancient pre-WWII inefficient engine design". Quaint, but not something I ever want to ride. But that is just me...🙂
 
I am a K bike guy to the core. When an R bike speaks to me it says "ancient pre-WWII inefficient engine design". Quaint, but not something I ever want to ride. But that is just me...🙂

My first BMW's were /5s and they defined the brand for me for many years, and I was even a K-bike bigot for a long time. But once I bought my first K - a 1986 K100RT - I really went over to the Dark Side, and now have two K75s, a K1200RS, and a K1 (and a R75/5). What I like about the classic K's is the power, the smoothness, the better frame and suspension, and especially the flawless running for 10's of thousand of miles - no fiddling required. They start and run immediately every time, and they run the same at the end of the day as at the beginning, and the same at the end of a 5,000 mile trip as at the beginning. Perfect German Consistency - in a very good way. Just do the regular services and replace fuel and tires as required.

Conversely, airheads are a great visceral motorcycle riding experience, and for many closely couple them to the pure joy of riding on two wheels and an engine. However, you will likely spend more time and money - at least over the long run - on the airhead over the K for maintenance and repairs.

I heard it said one time that BMW engineered the airheads to be infinitely rebuildable, and the Ks to never wear out. In my experience there is a lot of truth to that. For many, one of each is the right choice. :brow
 
Like many people, I've had a few airheads. The first one, an R60/7 I loved. Of course that was about 40 years ago and it was fairly new. The last one, an R80RT, I sold very quickly. Poor brakes, ancient charging system, worn shocks, small seat for two, and to my suprise, mighty darn hot on the legs with the RT fairing lowers. Airheads have that wonderful, simple beauty that the new BMWs have long since lost. And they are easy to work on, which is good since they often need it. Look at Matt Parkhouse in the Owners News. I think he carries about 20 pounds of tools and even a spare alternator when he travels on his. Along with that, everyone who has had one sitting in their garage for 30 years now wants $ 5,000 for it. And it will need everything done to it. Figure on $2-3000 in parts. Fine for people with a lot of money and who basically want an antique to putter on, and tool around town.

For myself, I think the K bikes are way underrated. I like the smoothness, and the fact that when you hit the button, they start right up, don't overheat in traffic, and are just completely dependable. The Honda of the BMW line, which is okay by me. My R80 took me two years to get "sorted out". I would say an airhead is like an MG, and a K bike is like a Miata. It just depends on what's important to you personally, beauty or functionality.
 
For myself, I think the K bikes are way underrated. I like the smoothness, and the fact that when you hit the button, they start right up, don't overheat in traffic, and are just completely dependable. The Honda of the BMW line, which is okay by me. My R80 took me two years to get "sorted out". I would say an airhead is like an MG, and a K bike is like a Miata. It just depends on what's important to you personally, beauty or functionality.

Well said.
 
For myself, I think the K bikes are way underrated. I like the smoothness, and the fact that when you hit the button, they start right up, don't overheat in traffic, and are just completely dependable. The Honda of the BMW line, which is okay by me. My R80 took me two years to get "sorted out". I would say an airhead is like an MG, and a K bike is like a Miata. It just depends on what's important to you personally, beauty or functionality.

:thumb:thumb
 
I was impressed with the k75 I owned for 13-yrs. But, progress does happen. The K75 was traded for a R1100RS that had the new para or tele-lever suspension and 20 or so more HP. Was the R1100RS as smooth as the K75? No. Absolutely, not. But, the new suspension was fantastic and more HP means getting to the speed limit faster. I wish BMW had carried the K75 concept forward as a new middleweight offering with a modern suspension, but that didn't happen. I think it would have been a unique and capable bike.
 
I wish BMW had carried the K75 concept forward as a new middleweight offering with a modern suspension, but that didn't happen. I think it would have been a unique and capable bike.

And 4V heads!

:thumb:thumb:thumb

Nope, instead they thought we wanted an R1800. :scratch





:dance:dance:dance
 
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