Just some more info....
Inasmuch as most of your bike wrenching is on Brit bikes (mine too… TR6es, Bonnies, BSAs, Nortons, Matchlesses…my GS just doesn’t require that much in the way of repairs), I thought I would add my two cents;
1- 1- The BMW GS clutch (Sachs) resembles the old air cooled VW clutch (Sachs) except, the BMW version is much more expensive and takes longer to replace.
2- 2- There is no throw out bearing support in the GS clutch design. Some owners find that they need to service the transmission input shaft and bearings as a result.
3- 3- The GS clutches often get contaminated if the transmission input shaft seal fails and the transmission oils the clutch friction surfaces.
4- 4- Recently, older (R1100 version) GS owners have experimented with using the VW clutch disc as a means of saving some money. They can be had for about $40.00. Some report that they believe the VW disk center splined hub is tougher than the BMW version and speculate the VW disk will last longer.
5- 5- Clutch/transmission input shaft splines need service from time to time especially if you ride the GS through water. Honda molypaste 60 is the popular grease for this application.
6- 6- While you’re in there, most would recommend an input shaft seal replacement as well as servicing or replacement of the Paralever pivot bearings.
7- 7- Also, removal and servicing of the starter is a simple job.