hhmmm.... this is now getting interesting to compare a 'clutch' of BMW Sportsters
Mine has the scary bouncing mud guard/wings and frequently came loose on my first long trip and one broke recently due to overtightening. Marlin weld their 'u' bolts to the upright but that is a pain if one fails as you'll have to grind it off and re-weld a new one.
Mine are currently serated and epoxy glued and the run up to Stoneliegh will be a good test of their suvivability.
We'll have to have a group design think tank at Stoneliegh this year and see what we can come up with!
Tappets, I bet mine were the loudest!! so make sure you've got the right feeler blade
Oil pressure... mine was low'ish and then dropped to zero. I put a new oil pump in and think I get about 50psi at 50mph. I supect it was the pressure release valve that goes or gets jammed rather than the pump itself, but just a theory.
Oil leaks... not a single drip since I first started it...(..note to self, better check if there's any oil...)
Diff whine... not noticed any at all, but i do have carpet and sound proofing in the boot space and my rear panels fitted so probably couldn't hear it above the noise of my tappets
Rear suspension...no issues....... I used Apex aftermarket lowered springs for a BMW e30. Ride height seems just about right.They come up on eBay regularly.
My brake light keeps comming on whilst driving along so probably another session upside down in the drivers footwell.
Happy motoring.......