RicK G wrote:They just bolt in and all you need is the later model gearbox with the tags to attach the anchor arm of the paralever and considering yours is a 1990 then it is probably there.
You need the complete paralever setup from a K100RS 16v or a K1100LT/RS including the shockie.

Did I read that the K1200 gearbox also fits for the swinging arm modification......and its 6 speed...?

A few years ago, BMWMOA Owner's News magazine ran an article about a guy who swapped a K1200 engine into a K100.  He used a K100 intermediate flange to adapt a K11 transmission and paralever drive.  The article said:

I wanted to use a K11 transmission, since they are an improvement over the two-valve transmissions. I also wanted the option of going Paralever later.  ...  A K100 intermediate flange was needed to mate the engine and transmission and a mixture of K11 and K12 clutch parts were used.

What that guy ended up with was:

K1200 engine -> K100 intermediate flange -> k1100 gearbox -> K100 driveline

That might or might not mean you can go the other way.  

What you're asking for is:

K100 engine -> K1200 intermediate flange -> K1200 transmission -> K1200 driveline

If the K100 intermediate flange mates with a K1200 engine, would a K1200 intermediate flange mate with a K100 engine?  I don't have an answer to that question.

I don't think I communicated what I was considering very well.  I was hoping that this would work:

k100 engine > k100 gearbox > K1200 swingarm/driveshaft > k1200 final drive

Finnigan wrote:I don't think I communicated what I was considering very well.  I was hoping that this would work:

k100 engine > k100 gearbox > K1200 swingarm/driveshaft > k1200 final drive

That's exactly what I understood but this is what I was asking...


k100 engine > k100 gearbox  K1200 gearbox > K1200 swingarm/driveshaft > k1200 final drive

The reason was that when I was out with my ex BMW friend on Monday we discussed this subject and he has a K1200 sitting out behind his place. He seemed to think that the early K1200 gearbox could be used as it was a final development of the brick engine.

Finnigan wrote:I don't think I communicated what I was considering very well.  I was hoping that this would work:

k100 engine > k100 gearbox > K1200 swingarm/driveshaft > k1200 final drive

I don't know if THIS --------^^^^^^^^^
is possible.  Big question
marks around this
concept.

I'll pull the trigger when someone can measure a k100 drive shaft for me.  Or I'll take mine off this weekend and check it out.  Gotta sell the parts anyway

I will ask my friend on this subject again. He was been working on BMWs since I met him in the early 70s when we both had Honda 500-4s and my mother took pity on him because she thought he looked half starved and needed feeding up. He still looks the same.....

I am 100% certain he said the K1200 gearbox and everything else back to the wheel would fit on the K100 his objection being that it would be a waste of money but if we all thought that way there would be no forum so we leave that argument out of it. Someone else on this forum investigated this 6 speed option too.

I have been investigating the 6 speed option and frame mods are necessary at the back mount to the gearbox.
The K1200 swingarm does not fit up to a 5 speed gearbox of a K100/K1100.  The shockie also is very different as it lays forward a lot more so a mount for that would need to be attached to the K100 frame.
The K1200 intermediate housing will fit to a K100/K1100 engine as the basic block is the same but the gearbox mounts are very different and as I said require frame mods or maybe an adaptor of sorts but that is a big maybe.
The biggest problem there being the numbers are right where the mods would be and that is a big problem here in Australia and most likely every where else.
As I said I have been investigating the 6 speed option and my next step has to be a complete drive line from engine back for a K1200RS.

Rick

Does that mean then that the modification is a gearbox/frame mounting one but that the 'mechanical' parts will mate up.

The rear shock is longer and leans forward more because the wheelbase was extended. There was a matching modification at the front end to compensate, the effect being that the engine is pushed forward somewhat when compared with the 8 valve K100.

Thats exactly what I'd like to know, it basically boils down to the swingarm fitting in the frame and the splines matching up to the gearbox

The gearbox will mate up to the engine without any drama at all, that is the easy part. You use the K1200 parts right back to the final drive and even the hydraulic clutch.
The six speed box has a very different mount where it joins the frame and the K1200 frame is an all alloy perimeter style frame.

The rear shock lays forward probably 30° more and meets the frame probably 4-5 inches down from where the K100/K1100 top mount is and the lower mount is on the swinging arm not the drive as it is for the K1100. You could mate a K1100 paralever drive unit to the swinging arm and use the K1100 shock.
The frames are totally different.
A shorter shock could be used but length, spring rates and damping would be a new ball game.

Pretty happy to get this for cheap

Are posting pictures disabled? I can't see the option to host them...

Nice looking bike.
I must make that fork change on my bike and get some of those super sticky tyres (tires).

They do work a treat.
Doesn't the tank leak?

Lets try these pics again...Unfortunately lost the previous message posting

Thanks to everyone who helped with the electrical gremlins.  Cant sync the TBs but the new front end and tires feel great!!

rosskko wrote:Nice looking bike.
I must make that fork change on my bike and get some of those super sticky tyres (tires).

The do work a treat.
Doesn't the tank leak?

Thanks man, the suspension is nice but the tires are what made the difference.

Haha yah the iphone takes pics right side up and posts them upside down for some reason, you'd think I'd learn by now!

When I went and did some further checking the reply was that mechanically the K1200 brick engine transmission will fit BUT the frame mounting is different and requires a frame mounting alteration. The time I wrote that I had a K100 and a K1100 and a K1200 brick sitting together. They were in my friends workshop.

The K1100 gearbox fits, along with the paralever and final drive etc. Buts that's still 5 speed.

Bike is on the backburner while I have fun with my brand new ride: 2015 Subaru WRX Limited!!

Ok, that's long enough with the Subaru. Back to work please.

Yeah exciting but too many wheels and it shoulda been red.

Could I have a pic of the speedo unit on the bike and where it came from?

Mossy1200 wrote:Could I have a pic of the speedo unit on the bike and where it came from?

The instrument is from a company called motogadget, they have a pretty good website if you want to find all the details.  The unit is called a 'motoscope light'.  Hope that helps