I like to use this page for that kinda stuff

http://budstein.com/cymbalweight/

You might find some pertinent weight evidence in here:

http://www.vintagedrumforum.com/showthread.php?t=53238

where I present a bit of my data on weights. On present evidence the weight ranges were already higher in the 1980s. As I mentioned in that link a MEDIUM in the 80s was the weight of a HEAVY in the 60s. And yours seems to be in the MEDIUM HEAVY category based on that copy of the good old Cymbalholic calculator. But that calculator doesn't pay attention to production decade, nor to whether you are talking about K Zildjian Istanbul vs Sabian vs Paiste vs Avedis Zildjian. That wasn't within the scope of the calculator project.

It's possible that yours is a Crash Ride, and if so it should have a bell which is a little larger in diameter and height than the Medium Ride model. But I take it you haven't got any ink left on top? At 2400g it's also within the expected range for a 1980s Medium Ride.

You might be able to narrow down the year via my year by year compilation of ink changes, although as always none of the years are to be taken as exact. Always remember to add a plus or minus two years to the year given there.

http://black.net.nz/avedis/avedis-by-years.html

Hope this helps.

Hi there - thanks for the input guys. I think mine is definitely a ride although the top markings are all gone. Seems like 2400 is about right - it is an amazing ride cymbal!

This works for me (USUALLY)...

I think a THIN 20" weighs around 4 Lbs on the nose ..1816g

Then,if I go to a 22" THIN..I add a LB...so,454g +1816g =2270g..

Then,I add ANOTHER Lb on if 24"...so,2270 plus 454= 2724 for a THIN....24"...

Does your's flex...if you grab at 3 and 9 'o clock,(from behind cymbal)and try shaking it a bit..NOT AS HARD AS YOU CAN!