.

[TheHatTuba]

.

[Bob Kolada]

The European F basses seem to be mostly .555. Tubaguy (tubaguy82,... whatever he is ) has a piston Eb with a .560 bore.
I've always thought a well designed .590 F, with similar proportions to a stretched out modern bass trombone, would make a nice horn- big enough for cimbasso stuff yet small enough to cover some bass trombone.

I believe J.c. Sherman has been building his last few Bb's with .620 valves.

[Dan Schultz]

I built mine with Miraphone Eb rotors.... .688" or about 17.5mm. It's now a BBb cimbasso.

[Bob Kolada]

Got a picture of that Kurath body, Joe? Or even better, it next to your little Conn F?

[J.c. Sherman]

The European F basses seem to be mostly .555. Tubaguy (tubaguy82,... whatever he is ) has a piston Eb with a .560 bore.
I've always thought a well designed .590 F, with similar proportions to a stretched out modern bass trombone, would make a nice horn- big enough for cimbasso stuff yet small enough to cover some bass trombone.

I believe J.c. Sherman has been building his last few Bb's with .620 valves.

My last chimp had a .640 bore, and it seams to be a little more "trombonistic" in it's timbre as a result. I also do something... proprietary... with the bore profile My other cimbassi have all been .689, but I won't use that again, I think. I've played nice cimbassi with larger bores, but the bell sections have to be wildly different to match up, and I don't have tooling to turn a bell like that.

For an F, .562 would probably work (my contra is that bore, so I would hope so!). Bob and I discussed this and I so think a .570 - .578 bore would work very well too.

J.c.S. (who may try .562 F chimp as an experiment)

[Bob Kolada]

That's not a bad looking bugle! I wonder if BOTH of those valve sets might be way too big though... I've had my eye on a bugle only Yamaha 201 euph body on ebay for a while.

J.c., what have you been putting in your giant trumpets?

[Lingon]

What is the smallest bore you've seen on a cimbasso? The smallest i saw was .656".

Many years ago there was a guy at the Royal Opera here in Stockholm that used to play an old cimbasso that looked like it was built by Boris Karloff Musical Instruments Inc. or something. It featured 3+3 rotary valves and a bore size of 0.547 in. When he played it the instrument sounded very well, but there were never anyone else that could make any (useful) noise out of it...

[TheHatTuba]

nearly unplayably stuffy

Even in F?

[J.c. Sherman]

Cleveland Opera had one of those F Cerveny bass bones with the .551-ish bore. Unplayable. In part it motivated me to build my own!