Bearing Edges

[Anonimo]

POST REMOVED BY THE AUTHOR

[Jerry Bembe]

I have seen bad bearing edges due to poor manufacture. I have seen this on Gon Bops and South American Conga drums first hand.

Gon Bops has not been consistent with their manufacture process of bearing edges. I have a 13 1/4" Gon Bops XLT tumba that was over 20 years old and looked brand new. This was because the poor bearing edge, so I filed it down and the drum now sings. Beforehand it was dead in tone due to the poor bearing edge.

I have a pair pf South American Conga Bomba drums that the shell thickness varied by double the shell thickness on side to side. This negatively affrected the bearing edge. I filed down the thicknes of the bearing edge to be even and the drums sang like never before.

[Anonimo]

POST REMOVED BY THE AUTHOR

[Joseph]

Is there any consensus on the most desirable bearing edge profile?

I tend to think that bearing edge profile (for any hand drum) has more to do with comfort on the player’s hands, rather than frequency response of the skin stretched over that bearing edge.
It doesn’t matter how good the head sounds...if it is uncomfortable (or painful) to play because of sharp edge...you're not going to play it much.

I’ve refinished a number of Gon Bops. A couple had nicely rounded (apparently original) bearing edges. Several more had what looked to be original bearing edges in good shape, but when I put skins on them, I found the edges to too sharp in both look and feel on my hands.
I ended up removing heads, giving bearing edge a more rounded edge, then resoaking playing surface of skin for remount.
A great improvement in hand comfort, though I would be hard pressed to say I noticed any difference in sound of head.

There isn’t a lot of online scientific discussion on the subject of “conga drum bearing edges”

Here’s some pics plucked from cyberspace of various rationales for bearing edges.
Mind the fact that none of these images is specifically addressing conga drums.

[Anonimo]

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[Jerry Bembe]

The best bearing edge I am aware of is Matthew Smith. He uses a mix of the round bearing edge silightly on the outer edge and a 45 degree edge on the interior. When I modify my bearing edges I follow Matthew Smith's method. I have made Playa Azuls sound great this way. The Playa Azul had a rough crappy bearing edge but with this corrected, the drum sings.

[pcastag]

I like matts, but I'm telling you guys the most comfortable bearing edge I've played on are mopercs, its rounded over just right, fits your hand like a glove.
PC

[bongosnotbombs]

Some Gon Bop bearing edges. A Gon Bop I refurbished, with before and after and an original. Both quintos.

[Bongobilly]

Bearing edges on Gon Bop's do vary. My Quinto was brought new @ Manny's in N.Y.C and for the longest time i was not happy with the sound so i hand filed a 45 degree edge inside and it open the sound of the drum. I have a Gon bops tumba and its has both inside and outside round over edges which is fine. That how i use to cut my bearing edges on my trap drums. Bigger drum double roundovers, smaller drum 45 degree inside and roundover outside. More tone for small drums less over ring for bigger drums. I leave a 1/4 inch area flat on top of two of my congas like Junior did with his and a 45 degree inside and roundover on the outside.

[Jerry Bembe]

Josesph's posting of the Pearl illustration makes more sense the more I look at it.

I have seen fiberglass Afros with a fat rounded bearing edge that sounded great from quinto to tumba but wood is a different story. The materials and the bearing edge need to be matched like choosing a skin for a drum.

Bongos not bombs look like the edge is flattened out. How does this affect the overall tone? Is it a more folkloric tone?

I have seen Gon Bops with 45 degree, rounded and flat bearing edges on different congas of the same model. This could make it more difficult to match a set together tonally. (Nothing that a file can't fix)

I agree with Billy about the 45 degree VS the double rounded. The 45 typically with wood drums produces a full tone. The rounded is more muted/muffled.

Perhaps the best of both worlds would be a 45 degree bearing edge with an adjustable dampener pad like the drumset drums have. This way a bright tone and a folkloric tone could be achieved from the same drum. Has anybody tried this?

[Joseph]

Billy,
Your observations about bearing edge profiles seems consistent with Pearl claims.

Pearl: "The fully rounded bearing edge provides...for a greatest boost in mid to low range frequencies."

Bigger drum double roundovers,

Pearl: "The rounded 45 bearing edge boosts mid to high frequencies "

smaller drum 45 degree inside and roundover outside.
More tone for small drums less over ring for bigger drums."

...but I'm telling you guys the most comfortable bearing edge I've played on are mopercs, its rounded over just right, fits your hand like a glove.

Like to see one. Any close up shots of a bare shell Moperc top edge?

[windhorse]

I'm finally re-heading my Isla bata this weekend because they came to me with crowns ABOVE the bearing edges! Eric took the old heads off last night, and discovered badly distorted bearing edges.. So, he has to file down and re-work each bearing edge.

[Mike]

I'm finally re-heading my Isla bata this weekend because they came to me with crowns ABOVE the bearing edges!

OMG!

Bearing edges are a really interesting topic.
Lately I have grown fond of the steeper, sharper cut edges,
I find the tone gets clearer, at least with my Gon Bops 3000
and the Delaporte.
What is more, an even bearing edge might be far more important
than the actual design of the bearing edge. Considering its function,
it has to fulfil two things: let the skin move smoothly across it when tuning
and keeping the resonating part of the drum´s skin deftly in place,
that is why evenness and smoothness are vital IMHO.

[Anonimo]

POST REMOVED BY THE AUTHOR

[pcastag]

Yes the complained that that the fingers split open , calluses hurt but never bearing edges. This says some thing about today's conga players, they all want to showboat with 3-6 congas but in reality they can't take the heat.

You're right, guys like Anga ( RIP) Giovani, Pedrito Martinez and Paoli can't take the heat!