‘He cut out an old valve and bunged it in the hole’
Bodges could have spelled disaster
Tubeless tyres can be wonderful things if fitted correctly, but the bodge job carried out by the owner of a Yamaha WR125 could easily have ended in rapid deflation.
Mark Birchill, of Stourbridge Motorcycle Centre, said: “The owner was chuffed that he had upgraded to tubeless tyres, but he still needed to seal the valve hole in the wheel, so he simply cut out the valve of an old tube with a collar of rubber and bunged it in the hole.”
The tyre may have said ‘tubeless’ on it, but the wheel was not set up to run without an inner tube. The existing rim tape wasn’t enough to seal off the spoke holes, never mind getting the tyre itself to seat on a rim that relies on an inner tube to keep the tyre in place, so he wasn’t able to get it above a few PSI and was soon on his way to SMC to get a new tube neatly seated in the belly of the rim to keep the tyre secure.
The other tyre trouble SMC dealt with recently wasn’t so straightforward. Chief mechanic John Birchill explained: “A customer brought in a recently acquired Kawasaki ZX-9R which had apparently ‘sprung a leak’ in the rear tyre.
“It looked more like a tubed valve as the valve outer was metal and threaded all the way down to where it disappeared into the wheel.”
With the tyre off he could see he was right as the previous owner had simply inserted an inner tube to keep the punctured tyre inflated for sale. But a tubeless rim has a flat base, so the tube didn’t have a channel to inflate into, which forced it into an unnatural shape, and it had gone pop.