After well over 100,000 k's on my 1993 R80GS a few thoughts from my side:

The circlip should be ok. What Mr. Ron is thinking about is that for 8 months in 1993 the circlip was omitted and instead the bearing was additionally glued in. Big crap - mine got unstuck at 18 thou resulting in a major gearbox balls-up. What makes sense is to check the 5 main bearings in the gearbox and replace them if necessary. And while you're at it, exchange the cog for the first gear against a shorter and the 5th against a longer ratio. AND while busy with the gearbox get rid of the standard clutch and replace it with a ceramic. Lasts for the rest of the lifecycle of the bike, even if you really grind it in sand and muck.

Exchange the standard front springs against White Power progressive springs.

Exchange the rear shock against either Oehlins, White Power or Wilbers if it isn't done yet. They can be rebuilt and last muuuuch longer than the standard Beemer shock. And perform much better.

The standard brakes are sufficient for dirt roads, otherwise careful riding... The rear brake can be fitted with softer linings which improves the drum brake considerably. The front disc could be exchanged against 320mm discs from HE (Supermoto Supermotard Funbikes Monobikes Felgen-einspeichen Speichenraeder Bremsscheiben HE-Motorradtechnik Freilassing Motorradfelgen) unfortunately only in German. But I found them to be adequate.

I rather like the standard handlebars, but lifted them by 2.5cm. Try Touratech.

Personally I'd stick to the fairings you've got. The newer fairings with the higher windscreen produces more turbulence around the helmet causing more noise. I finally sawed off my screen so it's even shorter than the older fairing.

I fitted the Acerbis/HPN tank and wouldn't like to miss it. Check the web - there are always second hands for sale.

Check the driveshaft, but if there is no play, just carry on. I've still got my first and it is still good. Mind you, I don't try to dice anybody, but I did lots of dirtroads.

Take a rotor along and don't forget the special screw to remove it. Take a spare diode board and regulator along.

My two-pence worth.
Hans

__________________
Only when we pause to wonder
do we go beyond the limits of our little lives.
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