Just got back from recharging my rear shock. OEM spec's 142 PSI. Mine had 60 PSI. Admittedly, the shock had 32K miles on it, but it's not like the pressure dropped 82 PSI in the last week either. Like brakes, it's a gradual thing.
Theoretically, if it was to loss pressure at a constant rate (which I doubt), the shock would lose 1 PSI for every 390 miles. That would mean that if you have 10K on your 12R and haven't done anything to your shock, you'd be about 25 PSI low. Now of course, I'm sure that the "rate" isn't perfectly constant, but still, that's a 18% drop in pressure.
Think about it. You might be "super anal" about your tire pressure, tire balancing, setting your suspension and maybe even changing your fork oil, but how many of ya'll check your rear shock's nitrogen pressure? Huh?
Almost any shop can check, bleed and recharge your shock IF... they have a NITROGEN NEEDLE! Call and make sure before you go yanking off your shock. My dealer had to order one from Motion Pro (less the $30 dealer cost). Very few shocks still use this needle valve. You might want to look into changing the bladder out for one that has a valve similar to a tire valve (most common). I would have, but my dealer was out of stock. The change them out on all their KTMs since theyrequire a $400 tool specifically for charging most of the KTM shocks. It's cheaper to just change out the bladder.
Anyway, recharging your rear shock is probably the cheapest thing you can do to "refresh" your suspension. Many dealers charge well under $20 for this service. Now that my dealer has a charging needle, I decided to charge mine to the RaceTech's spec of 200 PSI. If I hate it, I can always go back and bleed some of the nitrogen off.
Of course, to recharge the rear shock, you'll have to remove the silver cap at the end of the nitrogen cylinder. To do this and still have any hopes of reusing it, I carefully drilled a hole in the cap so I could stick a screwdriver in to pry it off. I'll have to plug the hole, but at least I can reuse the cap. Not that having the cap on is absolutely critical. I never replaced the one on my 7R, but it have the "tire valve" with a cap on the end. It's just that it'll be nice in keeping dirt and debris out.
Another thing to keep in mind when doing this... your suspension settings and sag. Since I'm replacing the springs with stiffer ones, I'll have to reset my sag and start looking for different compression, damping and rebound settings. If you don't, you won't be taking full advantage of what the recharge and spring can do for you.
I look forward to putting in the new stiffer fork springs and reinstalling the recharged shock for this weekend's rides. I know that it can do nothing but improve my bike's suspension. All for around $100. I don't think you beat that if your on a tight budget like mine.