Hi gurus,

Is it possible to confirm from the attached picture if this is a central stand that will fit my K100RS?

I have broken my central stand, and hence looking for a replacement.
I found a guy selling the following central stand for €15, he has provided this picture (below). He claims it's for a K100, however it looks almost more like a central stand for an old R-bike to me. 

Best regards,
Einar.

Looks like the early K100 to me, the one that breaks.

Definitely the one that breaks....I have one just like it. It broke. I still have the bits along with new bolts and bushes so I may just weld it up and fit the parts to make a complete refurbed assembly.

I bought a nice compete K1100 assembly from James Sherlock. It's on my 84 K100RT, direct fit but you need the complete assembly to do that.

It's in such good order its being swapped with the one on my K1100LT.

92KK 84WW Olaf wrote:I bought a nice compete K1100 assembly from James Sherlock. It's on my 84 K100RT, direct fit but you need the complete assembly to do that.

So if I understand correctly:
I should rather buy a complete K1100 assembly and fit on, but I will need the center + side stand w/the base plate.
I might buy the old stand as a temporary solution for a couple of weeks as long as I feel confident it wont tip the bike over again...

Question :
Does the side stand have the same risk of breaking ? As with many BMW side stands, they bend the bike over a lot, and have a reputation of fracturing.

Thank you for your respective replies; BobT and Olaf.

Best regards,
Einar.

Side stands don't break they just get worn bushes. The bolt and bushes can be changed easily and cheaply. 
The K100 16v also has the later stand.

All you need is the K1100 center stand. The base plates are the same part so you can use a K100 side stand with a K1100 center stand. (What I do on my Ks.)

I'd advise getting a K1100 center stand with a base plate as the base plate can be difficult to remove/install from the center stand.

The side stands can also rust out and break but if you have the rubber cap on the end then that will keep moisture out to prevent that.  (You don't have to use the BMW rubber cap.  A rubber cane tip from a medical supply store will also work.)

I was led to believe there was some change made to the stands and later ones may not fit. Open to correction on it but not sure of it.

Which was why I got the complete K1100 assembly, mounting plate, side stand and centre stand as a unit. I just undid the 4 bolts underneath while someone held the bike and swapped it in. Extensive use of WD40 over a week before hand all 4 bolts came out ok. Saved me trying to get the stand off, messing with bushes etc. The K1100 assembly came with grease nipples too and is unworn.

Make sure to use the rubber cap too.

Great input guys ! 
Thank you so much for taking the time to explain me these (simple but essential) basics.

I will take the time source a newer (preferably K1100) center stand and won't bother buying the earlier posted old version center stand !
To be seen if i can find one with the whole assembly or if i will have to mess with the bushings. 

Best regards.

If you use the K1100 side stand then you will not have the clutch lever side stand retractor setup that the K75s/K100 had.

Some people like the K75/K100 side stand retractor. Some people don't and remove it. (It's a matter of personal preference.)

The K1100s have a side stand switch the goes to the Motronic and will not let the bike run with the side stand deployed.

My 92 K100LT has the clutch lever operated side stand retractor, I did like that but you must make sure to keep it all well lubricated or you will eat cluch cables.

The 84 K100RT has the self retracting mechanism, hated it and got rid of it.

The K1100LT as said has the cut out so if you drop the side stand with the engine running it cuts out. To use it on others Ks just means you don't have the electric cut out.

Thank you for the further explanations. Much appreciated.

You raise very important points regarding the sidestand retract mechanism. Mine has the clutch operated side stand set up, I need to find out how it works, then take a decision on what to do.

The clutch lever is very hard to engage (if I compare to my R1200C and R75/5), I wonder if it's a cable grease issue or just the clutch characteristics.
To be investigated.

Is the side stand supposed to spring load all the way out to the end?

My 85 100rs side stand springs out about 2-3 inches short of the end of it's reach.  I usually use my foot to push it all the way out before leaning the bike over (you have to actually hold it out with your foot while leaning the bike over).  I forgot to tell my uncle this one time and he just about dropped the bike - it went out just enough to catch and rock backward into lock.

Does this point to bad springs or bushings?  Thanks for the info - I'm about to remove my center stand (hits my right side exhaust) and I'm being lazy about diagnosing - grateful for the experienced minds here

How come you have a right side exhaust? The K was on the left.

It's a project bike - not exactly stock.  I like the look of a floating rear wheel from the driver's side.

Here's a pic before I chopped the left side foot peg back.  The scrambler handlebars are removed and now clip-ons and I lowered the headlight a few inches since the pic:

boostd4 wrote:Is the side stand supposed to spring load all the way out to the end?
 I'm about to remove my center stand (hits my right side exhaust) and I'm being lazy about diagnosing - grateful for the experienced minds here

Yes, if it doesn't have the clutch-cable retraction feature.

That spring tension enables a self-retracting feature mentioned in post #10. Usually, the operator must dismount first, lower the stand then put the weight of the bike on the stand to keep the stand in place. When the bike's weight is removed from the stand, the spring tension retracts the stand.

There are two types of spring cams, one with a deep cutout and one with a shallow cutout.  This refers to part #12 in the diagram below:


The deep cutout can be seen in this photo from the BMW maintenance manual.  I don't have a picture but the shallow cutout extends only halfway as deep.


With the deep cutout, the retraction springs will be over-sprung and will hold the side stand in an extended position when deployed, even with no weight on the stand.  The shallow cutout will not over-spring the sidestand and will require the weight of the bike to hold the sidestand deployed.  Removing the weight off the sidestand by lifting the bike will allow the stand to auto-retract.

Fixing a self-retracting sidestand is easy; just extend the cutout on part#12 using a grinder.

robmack wrote:There are two types of spring cams, one with a deep cutout and one with a shallow cutout.  This refers to part #12 in the diagram below:

The deep cutout can be seen in this photo from the BMW maintenance manual.  I don't have a picture but the shallow cutout extends only halfway as deep.

Fixing a self-retracting sidestand is easy; just extend the cutout on part#12 using a grinder.

I don't understand. It seems to me there are two different return arms/spring cams with differing angles creating differing center lines through their pivot points to their associated tension spring attachment points. What is altered to change this relationship? The arm with the narrow angle—#9 in the first drawing—seems designed to redirect spring tension when it rotates past a certain point thereby holding the kick stand extended. The arm with the wide angle—#12 in the second drawing—doesn't seem to have that capability. Where does grinding it change that? It's too late at night for the use of coffee to help me with this.

Sorry, Laitch.  That drawing I posted was the only one to which I immediately had access on my disk.  BMW diagrams are crude at times and don't necessarily reflect reality.  I was only using that diagram to show the part to which I wanted to refer, and not as an example of either the shallow or deep cutout.

I used to have a K100 with the self-retracting sidestand and it bothered me.  I discovered the two cam shapes and altered the behavior of my sidestand by replacing one with the other.  That was a few years ago and I no longer have examples of either to show side by side.

In short, if one has a self-retracting sidestand, it is highly likely one has the shallow cutout cam; and the behaviour of the sidestand can be changed by changing that one part and not the whole sidestand. That's the point I wanted to make.

robmack wrote: That's the point I wanted to make.

Thanks, Robert. I almost completely understand that explanation without needing chemical infusion.

I have a self retracting one on the K100RT. The cam is a boomerang shaped part attached to the spring and works by rotating on a pin that catches the cam as the stand is lowered. I cut the pin with a hacksaw and without removing anything so the cam simply passes over it.