Valve stem repairs
The third tire component that could cause you problems on the trail is the valve stem.
It is a good practice to always keep your valve stems capped so as to prevent dirt from preventing the core completely closing. Very often, the source of a slow leak can be traced to the valve core sticking open ever so slightly, due to dirt or sand.
Plastic valve caps, valve cores, and rubber stems
Experienced offroaders suggest to use plastic caps rather than the fancier metal caps, on account of the metal caps tending to bind the threads and become seriously stuck.
In the event of a dirty or sticking valve core, the easiest solution is just to replace it. Most tire repair kits include a handful of valve cores, along with an extraction tool. Just insert the slotted end of the tool into the opening of the stem so that it engages the top of the core. Unscrew the core and remove. Let the escaping air blow out any dust in the valve stem. Then insert a new valve core and screw it back in. Re-inflate your tire to the desired psi.
If your rubber valve stem itself is damaged
That rubber nipple sticking out from your wheel can be the victim of a horizontally protruding rock. It used to be that the only field solution was to change the tire.
Replacing a standard tire valve stem is best done by a professional tire shop, as it involves some serious steps. The rubber tire itself must be de-beaded (removed) from the wheel/rim, so that there is access to the inside bulb of the rubber valve stem.
The bad valve stem can then be pulled or cut free from the metal wheel. A new valve stem is inserted into the hole; and the (optional) TPM (tire pressure monitor) can be re-attached to the bulb of the stem. The rubber tire is then reseated onto the wheel.
Easy enough for a tire shop that has special equipment, but not so simple for the home mechanic.
Although it is possible to change out a valve stem on a trail, it is not for the meek. To unseat the tire, first you have to remove the tire from the vehicle. Then the tire is partially slid under the vehicle, and a scissors jack is placed on top of the sidewall but under the side rail of the vehicle. As the jack is raised, it crushes down against the sidewall, thus breaking the bead. With the assisted leverage of a bar, jack handle, or long screwdriver – the rubber tire can be squished enough to allow a few fingers access to inside the wheel and to the old valve stem. A hundred or so curse words later, a new valve stem can be re-inserted.
Good thing you had a spare tire!
Fortunately, someone invented an easier solution.
Colby Tire Valves can be easily and quickly installed, in just minutes, and without the need to remove your tire from the axle.
As with most things, there are lots of YouTube videos showing how to install the Colby Tire Valves (which were invented by an offroader).
The Colby Valve is metal, and features a rubber compression collar that expands like a wine stopper or a molly bolt anchor when a locking nut is rotated.
To replace a damaged valve stem, here is what you do.
Remove the valve core, and then completely snip the rubber stem.
Use a screwdriver to poke the stem back through the wheel hole and allow it to just fall inside of the tire. It won’t hurt anything.
Insert the Colby Valve into the hole.
Use a wrench or socket to tighten the retaining nut, thus compressing the inner collar to seat & seal the new valve.
That’s it! So simple that even I can do it.
Colby Valves (available on Amazon) sell for around $30, so it makes sense to keep a set in your kit. They are available as “permanent” or “emergency”. The emergency style offer a wing nut for tightening, so that no tool is required. However, some metal offroading wheels may not offer enough clearance for the wing nut, so it is better to go with the permanent style that uses requires a wrench or socket.
If your tires do not have TPM (tire pressure monitoring), you can leave the Colby’s on permanently. Otherwise, take a trip during the week to the tire shop and let them re-do the valve.
