The valve on my mountain bike tire has a leak, so I want to go buy a new valve (and maybe a couple spares)... how much is the average cost?Thanks!
Just buy a new tube, I don't even think you can/want to replace the valve on a bike tube. $5 maybe.
Pump the tire up to max and then release the air that may clear any dirt out. If it's leaking around the base it needs patched or replaced.
It depends on whether you have a presta or schraeder valve. If a schraeder valve, you can buy a bag of them with a remover from an auto parts store for about $3.00 or so. If a presta valve, most of those cannot be replaced so it is new tube time. Are you sure it is a valve? Many times a puncture in the tube will leak through the valve hole AROUND the valve making it seem like a valve.
