I swapped the almost worn out (4.63mm) front disks from my RT boxer to the RS boxer and tossed the warped disks from that bike. 

On Sunday night I bit the bullet and ordered and new pair of disks for the RT and they where on the door step, first thing Tuesday morning. 

These are the same disks you need for a K1100.
 




Each disk is in it's own box and 2 new sets of pads where in one box. 
They come with a new hub and the bobbins are press fitted not attached with circlips.
The ABS ring lines up perfectly but I want to try and get a complete new set of bolts for the ring and the disks before I fit them.
These disks measure 5.63mm thick.




Total cost:  $455.75 Delivered.  


(I meant to put this in product reviews if someone wants to move it.)

Get some button head cap screws in stainless. Dont get normal bolts or socket head cap screws (allen head) they wont be narrow enough to clear the forks.
Clean the threads with acetone and reapply some green thread lock. You dont really need the red thread lock that the factory uses.
Many don't bother to use it but if the bolt worked loose then it could chew it's way through the fork leg without you realizing it and luck as luck is it will be in the middle of nowhere when it happens.

There was no thread locker on either bike when I swapped the disks and pads over so I didn't plan on using any on reassembly. Wouldn't you want to use Blue? I looked up Green as I've never seen it used before and it says it's for preassembled parts.

just wonder how thread locker would work at brake disk temperatures

Blue or green are much the same for holding I use the green because it will get into a thread and the blue wont  so the green serves both purposes.

Charlie apparently it is OK as the factory use it.  It probably would get a bit soft but it would still hold.

yeah I guess rick

anything that might stop the turning, even if just gummy residue

Thread locker?  Seriously? I put anti-seize on them since those threads are subject to corrosion.

Yes seriously if you put thread lock it will also prevent any corosion and factory do recommend it and use the red stuff from new.

I got a BMW manual for RBikes. They quote Loctite 243 but only for spoked wheels on the GS and R models. Cast wheels on RS, RT and S models only show a torque setting, no loctite.

I stand corrected, but I will still use the green stuff and the 4 wheels I have dismantled have all had the red stuff because I have had to heat the wheel with a hot air gun to get them out and one I needed to drill the heads off the bolts, not all but 4 or 5.

I'm sure both these bikes have had the front disks changed once already but I may as well stick to the BM manual specs.

All done without issue. Just need to get the exhaust and tank back on for a TB sync then all the tupperware back on for a test run. The rear caliper is leaking and a kit is coming for that but the rear kit does not include pistons only seals so fingers crossed that's all it needs.