Interchangeability?

[Red1974]

Is there any info available on the interchangeability of parts on these airheads? I have a 1974 R90/6. I'm curious as it seems there would be a great range of parts that would change out. Any info would be greatly appreciated. Nils J. Larson:Red1974

 

[20774]

It's a little crude and might not be 100% accurate...you can use RealOEM's on-line fiche. Enter you VIN and begin searching for parts. Say you find a part number and wonder if it's used on other bikes. Copy the part number from the page, go back to start of the program and use the Search by Part # link. Enter the part number in the box and it'll show you which other bikes use that part number.

Also, within RealOEM, you'll see date ranges that the part number is used on.

Something to try...

 

[lkchris]

BMW motorcycles are "parts bin" bikes.

In any given year (speaking of the large bikes)
the bikes have the same frame
the bikes have the same transmission (exactly)
the bikes have the same driveshaft, rear drive (except ratio)
the bikes have the same engine (except cylinder/piston and carbs)
the bikes have the same everything else (except badges)

Year-to-year changes are very small, too, especially within series. If changes are significant enough, it becomes another series, i.e. /5, /6, /7, etc.

There were two different R100 engines in 1977 and 1978 but after that they were all the same in the same year.

The biggest change ever occurred with the 1981 bikes and the 1985 change to the K-bike suspension was pretty big, too.

"Large bike" is used to distinguish from (early) R65, R80G/S, R80ST, R100GS, R100R.

 

[boxerkuh]

That is why we sometimes refer to our bikes of "bits-a-bike". (bit of this year, bit of that year, bit of yet another year). It allows our frugel minds to operate at the most economical way. That it is also good to own more than one airhead, or have one running bike and having a another "donor" bike.

 

[Red1974]

thanks

Ok, that all makes sense........thanks for the info Folks!

 

[QTreiber]

What changed in '81?

"The biggest change ever occurred with the 1981 bikes and the 1985 change to the K-bike suspension was pretty big, too."

Hello,

I am new to the forum. I am in the process of buying my first real airhead (1983 R100) and getting it shipped halfway across the country. I said "real" airhead as I also have a 2007 Ural Retro.

So what changed in 1981?

Thank you in advance and greetings from Colorado,
Armin

 

[kstoo]

Since I like my 1980 R100(T) and my 1982 RS equally ...
correct me if I am wrong but I am gonna run through a few of the changes in 1981 ... just for trivia fun ...
electronic ignition
no fly wheel, it is now a clutch carrier
some frame modifications (footpegs and shifter)
center stand and side stand mounting got really bad.
Brembo brakes
brake MC on handlebar

that is not that many changes or very obvious but pretty significant

is that more significant than the long wheel base, 5 speed /6?

is that more significant than the R80 - R100 /7 engines with new tank styling (S actually) and cushioned drive shafts?

 

[Red1974]

interchangeability..........

Assemblies perhaps would be a better term,what assemblies will interchange? Will a 1978 R100 tranny slide in and function? What other years and series fork and brake setups will bolt on successfully? Will an r100 engine bolt up and function? In my 1974 R90/6?

 

[108625]

Red,

Just curious, do you specifically need these major assemblies replaced, or are you just gathering information in case of future catastrophic failures or accidents?
Or are you trying to upgrade "bitsa" your /6 to a /7 or newer standard?
Just about every component on your bike was built to a standard to be worth rebuilding. A lot of swapping is possible, and can be interesting, but be carefull, you could find yourself riding a two wheeled version of Johnny Cash's Cadillac.
"I built it one piece at a time".

Bob

 

[Red1974]

curious

Well gosh........I guess I just want to know what my options are. I surely don't want to create a monster. I'm thinking "What if my tranny goes?" do I crate it up and send it for rebuild somewhere or do find a later model one locally if I can and slip it in? I like dual discs as well and maybe I can put later model forks on or something. I see your point about everything being worthy of rebuild on these bike though. I'm just trying to figure this stuff out as they're not making any more of these bikes and I might have to make do years down the road. Thanks Nils

 

[rpeckham136133]

In great sweeping terms, your 1974 can use lotsa parts from all /6 and /7 bikes. The transmissions and engines were pretty much interchangeable, keeping in mind different carbs, possibly different exhausts for different cc engines. There were iterations of instrumentation: mechanical tachs, then electronic tachs, that type of thing. And final drive ratios were different in order to deal with the different horsepower.

But as far as engine swap, tranny swap, etc, lots of possibilities. The big change came when they introduced the monolever (1985?), those trannys will not retrofit to earlier without lots of machinework etc. But the engines might...! They changed clutch/transmission input at some point before the monolever.

Probably your safest bet would be to stick with the /6 and /7 models if you are looking for easy stuff.

 

[lkchris]

that is not that many changes or very obvious but pretty significant

You forgot Nikasil cylinders , which are pretty significant, too.

The fact that the clutch carrier replaced the flywheel combined with the handlebar-mounted brakes means that the hand controls now require only reasonable as opposed to heroic effort and that the bike runs and shifts like something much better than farm equipment.

The electronic ignition means ignition maintenance is reduced to zero and the bike remains in tune and the system generates enough power to actually fire the sparkplugs.

It's more than just a switch to Brembos and handlebar-mounted reservoir, it's a change to better brakes. No adjustment required to get pads to contact rotor correctly.

 

[CO_G30]

It's a little crude and might not be 100% accurate...you can use RealOEM's on-line fiche. Enter you VIN and begin searching for parts. Say you find a part number and wonder if it's used on other bikes. Copy the part number from the page, go back to start of the program and use the Search by Part # link. Enter the part number in the box and it'll show you which other bikes use that part number.

Also, within RealOEM, you'll see date ranges that the part number is used on.

Something to try...

thanks for the "search by p/n" tip on realoem.com Kurt! All these years of using this site and it never occured to me to search for such correlations in this manner vice laboriously clicking on likely models/years.....