In this week’s copy of Motorcycle News, our very own Bryn Phillips has been helping a reader find the cause of his tyre pressure woes!
Despite having the wheels off of his Yamaha XJ600 five times to give the rims a clean, his three year old tyres continue to slowly deflate.
As Bryn explains, the only sure fire way to find the source of a leak is to slowly rotate the tyre and wheel assembly in a bath filled with water. If you start to see bubbles, these should lead you to the source (or sources) of the leak!
In this particular case, both front and rear tyres had the exact same problem, which leads Bryn to believe that the problem with with the bead seat area of the rim. If testing this in a water bath, you’d spot bubbles escaping from between the tyre and the rim.
This area of the rim can become corroded, and further to this, the rim can essentially weld itself to the tyre if it has been in position for some time.
When removing a tyre which has become welded to the rim, it can leave behind small flakes on the wheel, making he bead seat surface prone to slow leaks.
If giving your rims a thorough clean doesn’t help, it may be worth investing in another set of wheels in better condition, or having your rims powder coated by a reputable firm who will ensure the beat seat area is well cleaned before applying the coating.
Old valves can also begin to leak, and should be changed every time you fit a new tyre. Even if your old valves are air tight, it could be worth replacing them as you never know when they may start to fail!
