Circuit Performance Black Rubber Valve Stems TR413 30mm (100 Pieces)

I've probably used 2 dozen or more of these so far over the past few years. Zero problems, used for 35-50psi applications. Stored in a shed and just used 8 more. They're still like new.

I put these on my trailer wheels when I mounted four new tires and they work great. Just as good as the pro brand stuff I've used in my father's shop. No leaks, neither around the stem nor in the core. They've been holding steady at 80 psi for a couple weeks. As others have noted, they do fill pretty slowly, but this is as much a function of the cheap fill valve I'm using as it is the valve stems, so I'm not going to blame them for that.I'd also like to mention that if you have any dirt or corrosion around the valve stem hole when you install these, it will surely leak around the perimeter. I always clean mine up with a narrow wire brush attachment on my drill when they have corrosion, and I've never had leaks since I started doing that. It helps too if you squirt or brush some soapy water onto the rubber before you try to pull them through. A little wiggle and they'll pop right in. They'll leak if there's any dirt in the core before you screw it in, so make sure that's clean too.Given the price, even if an occasional one leaks, it's no biggie. Just cut it out and pop in a new one. They're basically disposable being so cheap. None of these leak so far for me, but I don't even bother with old valve stems any more. When new tires go on, I'll cut these off and pop in new ones. The rubber's only supposed to last 5 years out in the wild anyway, so they should be replaced regardless.

***2022 UPDATE***: I've now had two of these start leaking and fail, resulting in a blow-out on my trailer while going over 65mph. Very dangerous. I bought a new trailer tire and got my trailer home... a couple days later and the other tire was completely flat. When I tried to air it up the stem wouldn't hold air. I tightened the valve core and that didn't fix it. It was leaking from the large cracks around the base of the valve stem. TRASH. I now have to unmount every tire I've used them on and replace them before I have another blow out. If enough of us have this problem we should sue this seller. The seller refuses to refund me for this purchase.***Original Review***:I've installed these on about 4 sets of wheels (summer and winter tires for two cars) and after a year every one of them has deep cracks when you bend them. Whatever rubber they use is of very low quality. The last set of tires I mounted I ended up reusing the 7 year old valve stems because they had no cracks, and looked better than these that are a year old. They are not leaking any air yet as far as I can tell, but I won't be using them any more. I'll update this review depending on how Circuit Performance customer service takes care of the problem.

great product

Awesome for the price I've only done a couple sets of tires with them but now I don't have to use old valve stems I got new ones for cheap

This was used along with a bunch of PVC tube to make a water rocket and it did an excellent job.

Put 4 new tires ln GMC K1500. These stems woked fine for now. As long as they dont dry rot like some rubber products.

Good ...thnks