Shires dual bore valves

[Chatname]

Does anyone know what the differences between Shires’ dual bore valve and their newer Ralph Sauer dual bore are? It just says smaller on their homepage. Much smaller? Specs? Has anyone compared them?

[Burgerbob]

Pretty sure it's just the dual-bore valve, smaller relative to the normal rotor.

[Chatname]

So the difference would be the size of the rotor itself, not in the bore?

[Burgerbob]

I'm still not certain of your question... the Sauer model comes with the dual bore valve and doesn't have a specific one just for that model, as far as I know.

https://www.seshires.com/trombonevalves

[Chatname]

“ A new, smaller diameter, dual-bore rotary valve is fast and lightweight, and maintains the bore’s cross-sectional area through the valve.” From their homepage. It sounds like it’s different, but maybe I misunderstand?
Thank you for helping out, by the way!

[Burgerbob]

It's different from their standard rotor, yes. Smaller in exterior size. I'm not sure how the inside has changed, never been able to take one apart.

The Sauer models play very well, I've played 3 or 4 at this point. I wouldn't mind one!

I think this valve also comes on the Colin Williams model, and it's good on that too.

[tombone21]

The dual bore valve increases in port diameter along the air path, if that makes sense. The exit port diameter is slightly larger than the entry port. Overall, a smaller valve. The Colin Williams model comes with the standard, larger rotor valve with chamfered edges in the core. The wraps on the two are the same, though.

[Burgerbob]

The dual bore valve increases in port diameter along the air path, if that makes sense. The exit port diameter is slightly larger than the entry port. Overall, a smaller valve. The Colin Williams model comes with the standard, larger rotor valve with chamfered edges in the core. The wraps on the two are the same, though.

Interesting. The one I played at NAMM 2020 (that was a year ago??) said dual bore, or so I thought.

[Arvopart17]

It’s a great valve, I own the Sauer model and it’s definitely the dual bore valve. It’s got a really short throw and I feel like it’s slightly more efficient than a standard rotor. I heard a Shires rep say you think of Axial on one end of the spectrum and dual bore on the other from a blow perspective, but that doesn’t mean it’s stuffy. I’m not exactly sure what the technical difference is inside, and I’m probably not telling you anything you don’t already know - but I really like the way it plays for me, I feel like the horn just sings.

[tombone21]

Interesting. The one I played at NAMM 2020 (that was a year ago??) said dual bore, or so I thought.

We're probably both right. I've seen loads of configurations with the Shires artist bells, especially at trade shows.

[Chatname]

That’s a relief. I ordered a dual bore valve a while ago that is arriving soon (will use it with a .525/.547 slide, 2RVET7 bell). Then I got confused and thought maybe there are two different dual bore valves in existence: The standard and a new smaller one for RS. That’s why I asked here. Thank you for your answers!

[GabrielRice]

The wrap looks the same, but the tubing also gets larger somewhere in the middle of the dual bore valve section.

[Chatname]

Thank you Gabriel, that’s kind of what I suspected. Good to know!