It began decades ago, when I noticed that the profiles of a lot of bearing edges didn’t seem to match the profiles of plastic drum heads that were available. So I began playing around with bearing edges, and have continued to study their role in a drum’s sound.
Here’s what I think I've learned so far.
Close To The Edge
In the beginning, bearing edges were a nice-to-have, but not that big a deal. “Close enough” was close enough because calf-skin heads would always fit themselves to the drum. Plastic heads are not so accommodating. It's also not uncommon for a vintage drum to have somewhat irregular bearing edges, perhaps due to low tolerances at the factory, uneven shrinking of the shell material or physical damage. Such drums will be hard to tune unless given a bit of TLC.
Not All Created Equal
Modern drums are better suited to the profile of plastic drum head collars, but good design and quality control are not a guarantee of bearing edge excellence. You're right to expect perfection in a $1000+ instrument. However in the lower price tiers, the edges will naturally have received less attention. There’s a cost attached to bearing edges, and the labour costs will be reflected in the price of the drum. That said, a reasonably well made drum can often be 'up-cycled' by giving it a good bearing edge treatment just as a modest acoustic guitar can be improved with a high quality bridge saddle. The bearing edge is, after all, the drum's 'bridge'.
I'm So Confused
And so you should be. Options you may hear about bearing edges include: round-over, 30 degree, 45 degree, dual-45, reverse 45, 45 with round-over, bull-nose, baseball bat, vintage round-over. There are also different theories, applications, claims, boasts, and myths.
Yes, It Really Does Matter
An uneven bearing edge can be a nightmare, but a 'proper' bearing edge may not be right either. The edge profile can have a significant effect on tone and other factors, including: resonance, brightness, tessitura, sustain, body, and volume. Most drum makers these days tailor the bearing edges to the style and economics of the drum -- e.g. vintage style edges on vintage style drums -- or perhaps they finish them to a house standard, “That Great Gretsch Sound” being one example. Some companies even offer a choice of bearing edges.
My advice is to not worry about it unless there are visible defects in the bearing edge or you're befuddled by a drum's behaviour. You can find a lot of information about bearing edge properties online. There are also videos that can show you how to check your bearing edges, and if there is an issue, a drum tech can help. It's also not that hard an exercise for a do-it-yourselfer ... again, lots of videos on this.
Photo by Gfilms