My CBF250 has had a slow puncture in the front wheel for some time. On a tubeless tyre there is a common cause for this. A barrow full of water confirmed what I thought. The leak was not a puncture but was from the rim. This happens when the wheel corrodes and allows some air to escape.
|I removed the tyre - it was not pretty in there. Lots of corroded aluminium. The bike is used in winter and this is the effect of de-icing salt.|
|The tyre was stained with aluminium oxide|
|I cleaned up the rim with a wire brush and a scouring pad. I applied some petroleum jelly to prevent future corrosion.|
|This is the long way to fix this problem. The short way (and one that I'll use if this doesn't work) is a can of sealant.|
|The tyre passes the barrow test!|