250-500cc How do you get in there to adjust sag?

Is there any trick to getting at the shock nuts? Do you pull the upper mount on the sub frame?

With a hammer and a flat screw driver. Loosen the top nut, then turn the bottom nut clockwise for more preload or counter clockwise for less preload. Remember to tighten the top nut after getting your sag.

Motion Pro sells a neat shock nut punch that has a brass tip so as not to damage the Shock spring nut. Not bad priced. Your friendly Parts Unlimited Dealer can get you one. Even a long punch is better than a screwdriver. A screw driver will damage the nut so use that only in emergencies.

I use the end of a flat file, the part that would go into the handle.It's bigger and blunter than a screwdriver so it doesn't do any damage to the preload nuts.

A piece of 10mm aluminium round bar filed to a flat on one end has served me for many many years and will not leave a mark !
If it starts to look ragged on the end, file it again and another 10 year life span begins

I use 1/4 sch 80 PVC that I cut into 3/4" wide x 10" long; no messing up of the nuts with that. Once in a while I re-cut the end off the PVC to get it back to square. LOL I bought a sheet 4' x 8' sheet of this stuff 15 -20 years ago and still using pieces of it today.

put bike on stand loosen top ring nut (i use aluminium flat bar) and you should be able to turn the spring by hand which should rotate the compression ring nut, keep everything well lubed.

Be sure and clean the threads before turning the lock rings.

I honestly do not know but my girlfriend does know and thats all that matters

+1
But if it gets a bit stiff to turn by hand, I use a long screwdriver(or similar) to lever the ring around, as opposed to belting it. No damage and heaps faster than tapping it around with a screwy/punch.

Or you could buy the right tool for the job. I've always used a brass drift.

http://www.amazon.com/Ohlins-00710-02-Shock-Spanner-Wrench/dp/B00415XAH0/ref=pd_sim_sbs_misc_2