Well managed to get my bike back on the road last night did 20 miles (10 each way to work and back) without any problems which is good.

However there are two niggly problems I'm having one is I've put a naked k fairing onto the bike however I've had to put a nut on the top right hand side because it was catching the throttle cable. Now I know this might not be in the correct position or it could be because it's k100rs bars. Just wondered if anyone has managed to get it working with rs bars before.

Also I've got a police single seat from a k75. Now I've  got the k100 84 tank holder and all the brackets however it moves at the front. I was wondering do you need the one that clamps to the frame tubing as if I add that on as well the side pannel doesn't fit correctly.

Has anyone got a single seat fitted to any of there bikes I'd love to see the fitments in the correct positions.

Might be the year of the side panel, they changed a few times. I also suspect a K75 panel doesn't fit an 84 K100

Olaf do you know if the frame rails are narrower on an k75?

That was my other idea.

I think the K75 and K100 frames are identical aside from the angle of the front two members to which the front of the engine block mounts.  (Due to the missing cylinder at the front of the K75.)

All of the parts from the bellhousing back are interchangeable between K75s and K100s.

Even the gas tank mounting is the same. (With the exception of the rear tank mounting for 85 and earlier K100s but even then the dimensions of the tank itself are the same.)


The K75 gas tanks for the regulars, Cs and Ss are shaped differently and slightly narrower/lower capacity but the mounting is identical.

My K75 Frankenbrick has an 87 K75 frame its K100 gas tank fits perfectly.

I just checked and the same police seat is used on K75s and K100s.

http://www.realoem.com/bmw/enUS/partxref?q=52532300250


Here's the parts fiche for an early K100: http://www.realoem.com/bmw/enUS/showparts?id=0501-EUR-05_1982_K589_BMW_K_100_83_0501,0511_&diagId=52_3681#52532300250

Here's the parts fiche for a K75: http://www.realoem.com/bmw/enUS/showparts?id=0562-EUR-12_1984_K569_BMW_K_75_85_0562,0571_&diagId=52_3681#52532300250

The K75 battery covers might not fit a K100 tank perfectly since K75 tanks are shaped slightly differently but that shouldn't impact seat mounting.

See on the fiches it's part 22 that doesn't fit nicely onto the frame rails. Think that's the part that would relieve the lifting of the seat. The bungee strap does it's job for now I'll just have to play around with it I guess.

Kind regards
sam

Hi Sam, here's some pictures that might add to what you can see on the parts fiche.

The first two are of the front and rear hinges on a police seat mounting.




This next photo is of a police seat I mounted on my K75 which originally had a factory low seat fitted. I had to make my own rear hinge copied off that photo above and seat prop as I could not get hold of those parts at the time.


And this next one may be the important one for your issue. Note the small hook on the inside of the clamp piece that goes around the frame rail is located against the pin that comes off the frame to the T supporting the rubbers for the electrical box in front and tool box to the rear (circled on the photo). On my bike there was a piece of rubber bonded to the frame exactly where the front hinge had to clamp (can't remember why it was there now but likely to do with the low seat arrangement) so I removed that. With that hook located up against the frame pin the relationship of the seat to the tank should be right.


Good luck.

Hello Gaz do you have part 13 fitted with or instead of the clamp. I'm just checking as it looks like yours is a later tank with the two press studs. It's chucking it down here otherwise I'd get a photo up.

I'll have a look for that part on the frame either way to see if it's there on my bike. As soon as it dried up

You're right about my tank being the later type with the two posts at the rear. I have just looked at the links to the fiche and I do not have item 13 only the clamp item 22. Also noticed that my seat prop is at the rear whereas on the fiche it is at the front.

Maybe you can use the clamp type front hinge like I have in conjunction with the strap across the frame that your tank is secured to.

Interestingly while browsing RealOEM I noticed that part number 52532300330 (item 13, the tank strap with the hinge pin attached) has been superseded by part number 52532303103 which is the clamp type hinge pin that I have. This would lead me to think you can use item 22 on your bike even though you have the original style tank attachment.

Cheers