Extra thick Bach large shanks

[quiethorn]

Something I never understood is why some Bach large shank mouthpieces have extra thick shank walls. I had a 5GS like this and have a 6.5AL now. Do they just take the small shank versions and thicken up the shank?

[JohnL]

Do they just take the small shank versions and thicken up the shank?

On those two, yes. The 6½AL and 5GS are spec'd with a #420 backbore and a "G" (.261"/6.63 mm) throat in both large and small shank. The other size that's spec'd the same in both large and small shank is the 6½AM; #413 backbore with an "F" (.257"/6.53 mm) throat.

For comparison, Bach's "standard" spec for small shank is .230"/5.85 mm (no letter for that size) throat and a #402 backbore; for large shank, it's a .276"/7 mm throat with a #429 backbore.

That creates the curious situation where a small shank 6½A has a smaller throat and backbore than a small shank 6½AL, but a large shank 6½A has a larger throat and backbore than a large shank 6½AL.

[quiethorn]

Do the backbore sizes (#420, #413, etc.) denote anything meaningful in relation to their sizes?

[BGuttman]

It's the number of the tool Bach used. Don't know if it relates to size, but it might.

[AndrewMeronek]

I'm pretty sure that cutting the shank wall thicker is cheaper.

Especially if they are having trouble controlling the center line of the mouthpiece during cutting. I've seen a fair number of Bach mouthpieces where the inside of the shank is not centered to the outside.

[JohnL]

Do the backbore sizes (#420, #413, etc.) denote anything meaningful in relation to their sizes?

From the Bach mouthpiece handbook:

NOTE: Numbers are factory part numbers for tools. There is no numerical relationship to the size and shape of the backbore.

So all the numbers really do is tell you which mouthpieces have the same size backbore.

[quiethorn]

Okay, thanks for the info. I always feel/felt weird playing one of these because it feels like I'm basically playing a small shank with an adapter.

[JohnL]

Okay, thanks for the info. I always feel/felt weird playing one of these because it feels like I'm basically playing a small shank with an adapter.

That's pretty much the case. If you want something with a 6½AL cup that's maybe better matched to a large-shank horn, try a 6½A. I don't think Bach offers anything like a 5GS but with a standard large-shank throat and backbore.

[ssking2b]

The shank walls on Bach mouthpieces have been all over the map inconsistently for years. These days they are no better. If you find 1 that works, hallelujah...but you might find 9 others that are all slightly different. This has been an issue since the Mt Vernon days.

[quiethorn]

Well here's something that adds to the mystery. I just bought a large shank Bach 5GS from someone on the forum that does not have the extra thick shank walls--just normal width. Is it possible this one is older and maybe they didn't used to do the thick walls? It's in pretty decent shape, so I don't imagine it's that old. It plays great, but I haven't played one with thick walls for a long time so can't really compare.

[Doug Elliott]

There's no consistency.

[jph]

There's no consistency.

That's part of the reason I opted for a Faxx. Plus I wanted the smaller Faxx 4g (old-sized Bach clone). The new Bach 4G is nearing he size of an old 3G, on my embouchure anyway.

[harrisonreed]

I don't get why people still go crazy for the Bach mouthpieces. Other brands aren't that much more expensive, and are often based on or can be based on only tge best Bach examples, except that they are all exactly the same within any given model#.

Even the Mt. Vernon's -- "my magic Mt. Vernon 2G is so good. Completely different from any other 2G Mt. Vernon, and impossible to copy. Guess I am stuck with only one mouthpiece for the rest of my life and bully if it gets dropped or dinged up."

[mrdeacon]

Even the Mt. Vernon's -- "my magic Mt. Vernon 2G is so good. Completely different from any other 2G Mt. Vernon, and impossible to copy. Guess I am stuck with only one mouthpiece for the rest of my life and bully if it gets dropped or dinged up."

You say that now but you just haven't found that magic 2G yet