Motorcycle valve has a bulbous end which goes on the inside of the rim. This prevents the valve from going through the hole in the rim. A pump is screwed onto the top, allowing air into the tire.
Pressed my front tire’s tire valve in a certain direction I did, and air leaked out. This cannot be good. After checking the age of the tire, I knew that my tire valve needed replacement. In this case my DIY efforts proved insufficient, but I learned something. I had a local bike shop replace my tire and valve.
Tire valves are made of rubber which, given sufficient years, dry rot and therefore leak. Metal valves have a rubber gasket which, if over tightened, will also leak. Given sufficient years their gaskets will also leak. Still, for tight clearances, a 90ᐤ metal valve would make it easier to check tire pressure, especially for the rear tire.
Tire valves that break while riding result in near immediate deflation and can be catastrophic. There are many cases where tire valve failure has killed its rider. These small $3.50 items should not be ignored and do not last forever.
You can change your own valve, but a better solution would be to replace the valve with every tire change. This way there is less chance to have a leak.
Metal motorcycle valves have metal stems but also require rubber gaskets. These gaskets, if over tightened, will leak. Over time these gaskets will also dry rot and leak, requiring replacement.
The DIY solution uses a large C-Clamp in order to break the tire bead and compress the tire sidewalls sufficiently to be able to replace the valve.
I bought a large C clamp. My 1100s valve stems were rotted.I had a feeling the stems were leaking so I put pressure on them and POP they flew off. I placed the clamp with 2 pieces of wood clamped the tire a bit. This broke the seal and allowed me to get the new valve in from behind. I didn’t have any water based lube So I grabbed a tube of that intimate gel ( hey it is rubber safe) Got it in and with a pair of diag clippers and a piece of wood for leverage The new valve popped in place.
I had a couple of 6″ c-clamps and a big heavy duty screw driver.
I protected the rims with heavy cloths on one side of the rim to keep the clamps from digging in the rim. One side of clamp on the rim and the other side on the tire. Then used the c-clamp to compress the tire. I put one clamp about a foot to the rear of the stem and the other about a foot forward of the stem. Once you get the bead broke loose and the clamps pulled tight then you can get in there to seat the new valve.
For car tires this method also works. Instead of a C-Clamp they use a piece of 2×6, one end placed on the tire sidewall, the other end on the ground. The car is them driven up the 2×6 until the sidewall is sufficiently compressed to remove the valve.
In my case my relatively skinny 100/90/18 tire was not sufficiently wide to allow for this. The combined thickness of the two sidewalls did not leave me enough room to remove the valve’s bulbous end. Oh well, live and learn. I went to my local bike shop and replaced my tire and valve.