I've been working on this for a time (a statistician's hobby) and here's what I think is going on with weight:

The level of variation is about plus or minus 10% for a particular model. Say for a 20" Medium Ride the median weight is 2250g. That means the expected weight variation goes from around 2025g to 2475g. Once you get outside that range you are more likely looking at a model with a lower target weight (eg crash ride, thin, crash, paper thin, etc) or a higher target weight (eg medium heavy, heavy, rock ride, etc)

The 10% is an early (and rounded up) estimate based on

[LIST]

[*]current target weight ranges published by Zildjian (thank you Paul Francis)

[*]vintage weight ranges (occasional cymbals with ink intact)

[*]current weight ranges where the model and weight class ink is intact

[/LIST]

The reason we experience more variation in older cymbals (particularly 1960s and earlier) is that we're mixing up different models because the model ink is long gone. In another recent thread I reported on weights for 18" Avedis Zildjian cymbals with model and weight class ink intact and this gives the flavor of the number of models and variation we're dealing with:

http://www.vintagedrumforum.com/showthread.php?t=60539

Then to make matters of interpretation more complex, the target weights for something like a 20" Medium Ride also changed over the decades. The targets got heavier (going from 40s and early 50s vs later 50s then 60s, 70s, 80s) and then were reset in 2013 for the A Zildjian series back to the 60s.

As far as sound goes for a given diameter: weight has a role and so does the curvature of the bow (higher curvature = holding more tension = higher pitch), and the size and shape of the bell (the bell radiates the higher frequencies), and the degree of taper (metal getting thinner towards the outer edge). These parameters all interact and there are others in the mix as well. I rely on my cymbal maker friends to help me with cymbal morphology and sound. I'm just the numbers guy.

Thank you Zenstat for the amount of time you put into these stats and for taking the time to share your knowledge with the rest of us through very detailed responses!

Is it safe to assume, with the heavier weight and the keyhole, this cymbal is not particularly valuable or desirable? It also has a few small nicks around the edge.

Wes

The link in my signature takes you to my price research. Here's a direct link to 20" results

http://black.net.nz/avedis/avedis-prices.html#20

Since that earlier analysis I've now got 75 completed sales of 1960s 20" cymbals. The expected median price would be around $80, and half sell for between $70 and $120. That is ignoring weight but taking condition (keyhole mainly) into account. If I focus on just those which weigh more than 2400g that knocks the expected median price back to more like $65, although there is still lots of variation around the expected value. There are people who like heavier rides, it just seems there aren't enough people seeking heavier rides to bid prices up to match the prices which lighter rides go for. :2Cents:

Wow..

The lightest (60s) A..20 I've ever had was 1825g.

But it had a minor circular crack 1/4 way around the bell,

I didn't want to be the one who popped it..so away it went.