Valve stem/core

Aloha guys.

I recently removed valve stem from my KZ cast wheel because I'm sending them out to have it powder-coated. Before this, I have the shop removed the old 25+ years old tires from the rim. can't remember which one, but one wheel didn't have the stem at all, and one only had stem, not the core inside. I'm pretty sure the shop removed the core as that thing was same with the tire, 25+ years old sitting outside.

Anyway, my question is, I know I need to get one stem, but the other one without the core, can I reuse the stem and just replace the core? I know nothing about the valve core, so I don't even know if they are universal/common size or they're unique with, say motorcycle or cars.

Anybody have any knowledge or experience with these? If I have to, I have no problem grabbing two new ones, but want to know if I can reuse the old one. These are not cheap any more...........

BTW, the stem I remove looks to be in good condition. Little rust at the base, but looks to be just the surface rust, and the inner part of the stem is still good. Rubber is still soft and pliable, and doesn't look bad at all (remember, it did have tire on it until recently).

You can just put a new core in the old valve. I would probably swap it out just so I could be sure it will be fine when the new tire is on. Having said that, if it has been fine and the rubber looks good, it shouldn't be a problem reusing it. How was the tire holding pressure before you took them off? Did you need to put air in the tire every week or so?

I'd replace the entire stem since the rubber ages poorly. Valve stems are cheap.

Questions
You run tubeless on cast rims ?
If so I would replace the whole stem assembly . I purchased my last ones from a local auto parts store and they were cheap.
I would not reuse the old parts if for no other reason the rubber degrades , especially after removing the stems from the rims .
Valve stem cores for stock style Schrader valves are a common size . Never had a interchange problem.
Dave

Those early cast wheels don't have a rim that's safe to take a tubeless tyre.
If someone has some how fitted a tubeless tyre and valve i would revert to using a tube..

He didn't say, but from his signature an 82 GPz 750 should be tubeless. I'm assuming those are the wheels in question. I would go ahead & get new valves stems.

The front wheel on my 750E is rated tubeless but it doesn't have the extra bumps in the rim profile (to keep the tire seated on the bead when deflated) typical of tubeless wheels. To me this wheel is no different than an earlier cast wheel rated for tube install, other than drilling of the valve stem hole.

Here's the KZ550 rear wheel I installed. Tubeless is cast into both the Fr & Rr.
The profile w small ridges is the same as the stock 48-spoke tube-type wheels they replaced.
The 70s wheels I've seen don't have any ridges. some wheels have very pronounced ridges.

Sorry guys. I did write cast wheel thinking all cast were tubeless, so I thought that would eliminate the confusion. But yes, my tires were tubeless. It's off of my 82.

Also, thanks for all the advice and input. Guess I'll just replace the whole stem, both front and back. They are about $21 each from Partzilla. Bit expensive for a stem, but I do believe in better to be safe than sorry, so getting two, maybe three just in case.

Just trying to save every pennies where I can. Restoring two bikes and maintaining one Monte SS (86) with problem giving DD Lincoln (LS), every penny counts.

Now, on to getting new tires..........................

Ojisan rider wrote: ................. But yes, my tires were tubeless. It's off of my 82. ....................

Maybe it's a matter of semantics, but the tubeless type tire does not mean the wheels are the tubeless type. It is ok to run tubes in tubeless tires. This is normally done all the time because tube type street motorcycle tires are pretty rare. The decision as to run or not run tubes should be based on the type of wheel the bike has. Ed

Here are some less expensive options. Where clearance is tight, I really like the metal ones with the 90 degree bend.

www.denniskirk.com/search/Valve+stem.q

650ed wrote:

Ojisan rider wrote: ................. But yes, my tires were tubeless. It's off of my 82. ....................

Maybe it's a matter of semantics, but the tubeless type tire does not mean the wheels are the tubeless type. It is ok to run tubes in tubeless tires. This is normally done all the time because tube type street motorcycle tires are pretty rare. The decision as to run or not run tubes should be based on the type of wheel the bike has. Ed

His bike has tubeless rims.

Regarding saving some money on tires, the Shinko 712 and 230's have a very good reputation. Only negative I've heard is they don't last particularly long. Many other cheap tires such as Dunlop 404's or Kenda Challengers are NOT nearly as good from the performance standpoint.