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My new King has what I would describe as short lengths of tubing the same diameter as the slides inside the tubing. I discover them while cleaning and re-lubing my slides. I don’t (or can’t) see them anywhere else but the main tuning slide. What purpose do these serve?

bore spacers...to keep the bore (mostly) consistent at 11/16".

Thank you bloke. I just never realized those were there. The function makes perfect sense. Are they just held in place by friction? One of mine came loose while cleaning with a swab. I just pushed it back in place. I wasn’t happy with my slide grease and was trying to get all the old stuff out of the bore. Should those space be able to come out that easily?

They generally are pretty tight, but it does not matter. I like to be able to remove them. When I build my own stuff I lap them into their home so that they move as a slide would. Others I know have tack-soldered them into place, which I think is a mistake, personally. If yours is as loose as you say, just keep it greased with whatever you are using. It will be fine.

These are mostly used in long tubes where there is both an upper and lower slide. If the slides are not long enough to add up to the length of the outer tube then a spacer is installed to keep the bore all one size (except for where a slide is pulled out) as Joe said.

the elephant wrote: ↑Fri Oct 29, 2021 12:04 pm These are mostly used in long tubes where there is both an upper and lower slide.

Please pardon the thread hijack (and the possible stupid question) since the OPs question was well answered and the elephant's comment brings up a question I've always had. The third and fourth valve circuits of my CC have both upper and lower slides as mentioned above. Is there any reason for what seems a redundancy other than to get the range of upper slide manipulation in the best comfort zone?

I’m not sure what you mean by redundancy.
If you mean that an upper and a lower slide are redundant, I have always viewed the lower slides’ purpose as mostly being a way to clean and maintain a circuit.

As far as bore spacers are concerned, it’s pretty obvious that their purpose is to cut down on unnecessary friction for slides that might be regularly pulled (yes?). If an upper slide is long enough to pull for however far it needs to be pulled, other “bore” tubing can just sit inside the circuit (“bore spacer”) as a “deadman”, instead of having to be dragged along as extra weight and extra tube-to-tube friction.

Thank you all for the responses! I took out the loose one again, and greased it say the elephant suggested, then re-inserted it. I tried to take the other out to do the same, but I could not extract it the way I did the other (a tight rag on a slotted swab). So I guess I just won’t worry about it. This is the only slide where I can see them on my horn, and it is the main tuning slide, no upper slide counterpart. So what bloke says about these being used on slides that are pulled a lot makes a lot of sense. My new style King has upper and lower 1st and 3rd, upper only 2nd, and lower only 4th and main tuning.

bloke wrote: ↑Fri Oct 29, 2021 1:13 pm If you mean that an upper and a lower slide are redundant, I have always viewed the lower slides’ purpose as mostly being a way to clean and maintain a circuit.

Thanks Bloke. I thought there was some kind of deeper reasoning behind it, but this makes perfect sense as each has a water key and it is certainly easier to snake around the bend of a short slide vs a long tube.

Worth wrote: ↑Fri Oct 29, 2021 2:35 pm

bloke wrote: ↑Fri Oct 29, 2021 1:13 pm If you mean that an upper and a lower slide are redundant, I have always viewed the lower slides’ purpose as mostly being a way to clean and maintain a circuit.

Thanks Bloke. I thought there was some kind of deeper reasoning behind it, but this makes perfect sense as each has a water key and it is certainly easier to snake around the bend of a short slide vs a long tube.

It’s also easier to dump these slides in some cases than using the water key.

Depending on the horn, sometimes I’ll use the lower slides to set the default “shortest loop length” so that it’s easier to manipulate the top slide. This is how both of my horns get set up on third and fourth valve.

matt g wrote: ↑Fri Oct 29, 2021 5:07 pm It’s also easier to dump these slides in some cases than using the water key.

Depending on the horn, sometimes I’ll use the lower slides to set the default “shortest loop length” so that it’s easier to manipulate the top slide. This is how both of my horns get set up on third and fourth valve.

Thank you for sharing these tips, much appreciated.

Update: lest anyone think I’ve lost my marbles, I decided to pull my slides again and look down with a flashlight. Turns out, all of slides on my new King 2341 have these bore spacers! The only place where they aren’t installed is on the long side of the first valve. Neither upper nor lower have one there but they are present on the short side. All other slides have spacers on both sides. Please pardon my ignorance. Didn’t want the wrong information to be here so I decided to correct myself.