Shires Q Bass Rotors

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Shires Q Bass Rotors

Post by posaunebone » Wed Oct 13, 2021 4:39 pm

Hello all!

Wondering if anyone has had any particular issues or made modifications to the valve section on the Shires Q Bass.


Better trigger action (Gb paddle is pretty sluggish even immediately after clean/lube).
Cleaner valve transitions
More open low register (but not thayer open)
A perfect low C or B natural every time :lol:

Love playing the instrument, but the rotors are much more Eastman 848 then Shires Custom from what I can gather. The tell tale super lightweight rotor caps and iffy threads, as well as some plain brass ferrules give it away.

Wondering if anyone has done rotor swaps on a Q series Shires, seems like given that they are already oversized, some wild wrap geometry changes might not be necessary. Hoping somewhere out there has a Q Bass to measure against some Instrument Innovations valves.

They do appear oversized and similar tube spacing to the instrument innovations rotor on my 42 (which I LOVE). Haven't pulled them out to see what the internal geometry looks like, and doesn't seem like there is any porting/venting on the Shires, so I would think swapping the rotors themselves would make a nice upgrade.

Obvious answer would be to just get an actual shires section to compare and blow on, but there's just something about tinkering and customizing that is inherently more fun and possibly cheaper too if I'm not opening a giant can of worms.

I am by no means a monster player, but at the same time I know there's some opportunities to help this thing shine! It's already super fun to play and amazingly easy to pick up as a doubler, but a bit of tinkering might take it to the next level.

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Re: Shires Q Bass Rotors

Post by Elow » Wed Oct 13, 2021 5:24 pm

I had the same problem with my Q axial Gb valve being sluggish. After like 3-4 days after cleaning they would get sooo sluggish. Probably just because it was thayers, maintenance was a big reason i switched.
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Re: Shires Q Bass Rotors

Post by hornbuilder » Wed Oct 13, 2021 5:53 pm

You can't swap out rotor cores. There are just too things to take into account.

If you want different valves using that valve tubing, it is a complete disassemble and re-build job using new the casings, and potentially some new branch parts.
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Re: Shires Q Bass Rotors

Post by modelerdc » Wed Oct 13, 2021 8:23 pm

As for sluggish rotors find a good tech. I have a shires Q here right now, the first valve was slowing down, took it to a tech, and a good professional cleaning and now it's fine. The Q seems to play very much like my regular Shires bass, and the low register is much like good rotors. I do have few suggestions: first try the C tuning slide from the Shires custom line, for me it's a noticeable improvement. You could also try the duo bore slide (or more open pipe) although these change other things as well as making it more open. finally you just might be happier with the Shires openness of the Shires Q with Thayer valves. As far as a good low C and B every time, that's up to you. A Q with rotors will have more resistance on low C and B than a very open Thayer, Hagemann or True bore horn, but you should still be able to play low C and B reliably and well even on rotors.
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Re: Shires Q Bass Rotors

Post by posaunebone » Wed Oct 13, 2021 8:59 pm

Oh yeah, the Low C / B is totally on me. Failed attempt at humor :lol:

Tuning slide is an interesting option to try out, and possibly just seeing if there's some factory gunk in that rotor that's settled in since new may help with some of the sluggishness. Not dirty or visible buildup anywhere, but a good ultrasonic cleaning never hurt anything either! If the tuning slide doesn't make a notable difference then maybe on to surgical options.

As for the rotor swapout, I did mean a full valve+casing swap and attempt to use existing tubing, not just jamming the core in. I'm going to have to try and compare the exact dimensions of my instrument innovations against the Shires Q rotors to see how crazy the shifts to the tubing might be. I'm going to take a closer look at the linkage too, might not be legit minibal so that can make a big difference too.

I had tried a few leadpipes and really ended up liking the MK George Roberts in nickel in this bass. Borrowed from a friend and liked it a lot. May be worth going down that rabbithole as well and start playing around with more pipes.

Thanks everyone!
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Re: Shires Q Bass Rotors

Post by elmsandr » Thu Oct 14, 2021 7:30 am

posaunebone wrote:
Wed Oct 13, 2021 4:39 pm
as well as some plain brass ferrules give it away.
Just wanted to note that Shires uses some plain brass ferrules on their custom line, too. There are some on the Trubore section next to me and on a rotor section that I used to have.

(sold these a while ago, but you can see some plain brass ferrules mixed with some nickel ones).
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Re: Shires Q Bass Rotors

Post by WGWTR180 » Thu Oct 14, 2021 8:27 am

The pros that I know who play the Q rotary instruments have zero issues with Low C and B. The other "issues" I cannot comment on.
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Re: Shires Q Bass Rotors

Post by posaunebone » Thu Oct 14, 2021 11:40 am

Ah! Cool! Definitely just jumping to conclusions / making assumptions on my part then, I stand corrected about the ferrules. Maybe I just hadn't seen a standard shires bass in a while. The valve caps/threads are a bit suspect though.

Thank you everyone for the input - as is true with most things the simple fix is usually the right one.

Good tech thorough deep cleaning / adjustments where necessary, potentially look at improving linkage with instrument innovations parts (the saddles maybe?) / Legit Minibals.

Tuning slide - going to give a C a try. Picked up a used seamed gold brass from brass exchange last night. Mixing alloys has always worked for me too so it will be nice to add that gold brass into the otherwise Yellow instrument / nickel crook+leadpipe.

I've already got a pretty wide open GR leadpipe, so maybe trying something contrasting like a MV50 pipe might change things for me too.

Oh, and practice to get those C's and B's more reliable rather than blame the horn :mrgreen:

Still can't help wanting to tinker though. I blame my chronic gear acquisition syndrome.
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