DIY disasters: ‘We’ve never seen a chain set so tight’
Mechanic Mark Dickinson helped a Suzuki owner out of a tight spot
When a Suzuki GSX-R750 owner complained of ‘surging’ mechanic Mark Dickinson suspected the chain. Dickinson, 37, is Head Technician at Yamaha dealer, DMC Motorcycles in Dudley. He said: “I listened to his description and wheeled the bike around the workshop. As soon as I pushed on the bars I heard a ‘creaking’ sound, which I knew was a tight spot on the chain.
“The chain didn’t look dry, so once I got the bike onto a paddock stand, I started to spin the back wheel. Normally you can spin a wheel easily with your hand – but not this bike: it got harder and harder then it freed off for half a revolution, before tightening up again.”
The owner seemed to have been adjusting the chain for some time at the tight spot, instead of the loosest point, as the tight ‘spot’ was actually a ‘region’ over half the length of the chain. Because the chain couldn’t turn cleanly it had hooked the front sprocket and had started to wear the teeth on the rear sprocket as well. So a new chain and sprocket set was required.
“The rider was lucky it didn’t spit him off. It was under so much tension the load going through the wheel and gearbox bearings was immense,” added Dickinson. “When I adjust a chain I always start with the bike up on a paddock stand so the rear wheel is lifted off the ground allowing you to rotate it to find the tight spot easily. I then set the tension at the loosest point on the lower run of the chain using the figures stated in the manual.
“In the end all the owner needed to pay for was a chain and sprocket set, which cost about £200 including labour, as against two grand for a major rebuild – or even his life if it had locked the rear wheel.”
‘The load going through the wheel was immense’