Terrifying tyre abuse revealed
Top technician, John Birchill, exposes tales of truly terrifying tyre neglect
Swinging a bike through bends, or filtering seamlessly through heavy traffic are two of the great joys of biking and it’s all down to the tyres. So you’d expect riders to look after them, right? John Birchill, of Stourbridge Motorcycles doesn’t. “I had this R1 come in the other day with the rear tyre down to the cord for almost half its circumference – and that’s not unusual,” he tells MCN. “You wouldn’t believe the number of riders who’re completely oblivious to the state of their tyres when they bring them in. Cord showing is quite common. The problems often start when they switch from some middle-of-the-road sports tyre to a full-on track tyre like a Supercorsa. They expect to get the same mileage out of it and come back after 2000 miles saying ‘the tyre’s no good’ because it’s got a flat-top profile like Suggs from Madness. You have to gently point out you’re never going to get 5-10,000 miles out of any rear tyre on a large capacity sportsbike.” Then there’s pressures: “When the season starts we get bikes coming in that have been under a blanket for six months and the guy’s completely unaware the tyre pressures are now just 8psi in the front and 12psi in the rear, instead of 36 and 42.
“A bike with pressures that low would be so wallowy in bends you couldn’t steer with any sort of accuracy and would spin on the rim if you wrenched the throttle open. Even running a few psi down will cut mileage by up to 20% as the tyres heat up more, accelerating wear. “Getting into a weekly habit of checking your tyre pressures is a must. Remember to do it when the tyres are at ambient temperature, so before a ride, or maybe an hour after you’ve stopped. If they’ve lost some pressure, that should be your cue to take a longer than usual look at the whole tyre, slowly spinning it to check if there’s a nail or tack embedded, as well as for signs of wear, cuts or slits.”
‘Get into a weekly habit of checking your tyres’