Originally Posted by
njkayaker
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It doesn't matter whether people use them. The issue is that some people are under the impression that the nut and the cap are necessary or provide a significant benefit. The fact is is that they aren't and they don't.
The cap is to keep the valve clean so it works better and provides some protection, same as with a schrader valve. To top off the tires you just remove the cap, instead of possibly needing to clean off the valve first. Keeps the pump head cleaner too. I buy the aluminum caps because the black plastic ones always crack and fall off.