I removed the rear wheel (a relatively straightforward job) with the intention of removing and refitting the sprocket (replacing the sprocket if the holes had elongated in any way).
This is where the fun started. Despite being loose enough to allow a degree of rotational movement in the sprocket, the bolts were simply too difficult to turn in either direction. Remembering that the are already weakened by the action of the rotating sprocket, I applied localised heat and very gentle (but maximum) force with the result that a further three sheared to go with the one that had already done so.Only one came out cleanly. This revealed the cause of the problem as well as a paradox. The entire thread had been liberally coated with enough threadlock/superglue to keep the propeller on the QE2. I still can’t figure out how they became loose in the first place. This was of course compounded by the natural action of a steel bolt to seize in an aluminium thread.
As the wheel was already out of the bike, I lifted the carrier off the cush rubbers and headed for my mate in Potters Bar who is equipped with a bench, a sturdy vice and a set of “Easy-Outs”. Even with further application of maximum heat, and being drilled clean through these bolts were not coming out – with the inevitable result that the Easy Out snapped.The carrier then went to CAM Engineering in Potters Bar http://www.camauto.com/cameng.html – it would have been fairly straightforward for them to drill out the sheared bolts – but the broken Easy Out added another dimension to the problem and increased the estimated cost to “up to” £75.
I checked with http://www.gileraspares.co.uk/ online and a new carrier assembly is £74 – but delivery time is “up to” a month (there’s that “up to” again !)So, CAM Engineering sorted the original carrier – after removing the broken bolts and repairing the damage, the carrier was drilled right through to allow slightly longer bolts with Nyloc nuts to secure the sprocket - there’s plenty of room behind the sprocket so I can’t understand why it wasn’t made that way in the first place.
If there’s a small crumb of comfort in all this, there’s absolutely no discernable wear in the original sprocket – even after 10,000 miles.Of course in hindsight it might have been better to have taken it in under warranty with a "loose sprocket" but any workshop would have faced the same problems - it would have been their problem not mine and I might have been without the bike even longer (let alone the inconvenience of taking it there in the first place). This way although it cost money I was back on the road more quickly. At the end of the day the fault lies with Piaggio for supergluing the bloody bolts in the first place.
