Sprocket cover blown off (!)

[jjdugen]

CBR 900 RR-T.
Out for a (spirited) ride with a good friend today. Heading up some back-roads and I heard and felt a grinding, almost as if the footrest had touched down. (I'm pretty good, but was nowhere near that lean angle.)
Stopped to check, nothing untoward.
Very spirited ride back home, motorway 'speeds', came off into the city, friend waving his arms. Smoke pouring from the front sprocket area, stopped, and the old chain oil set merrily on fire!!!
Took it gingerly home, no sign of any distress, no funny noises, smooth as you like..... curious and curioser!
Got home to take a proper look. Plastic sprocket cover hanging loose, the speedo drive plastic that fits on the sprocket bolt melted, closer look, all the alloy surrounding the sprocket from top bolt to where it comes close to the case casting gone!
Absolutely no chain damage, (brand new DID), anally tensioned to perfection, lubed to within an inch of its life.
ALL I can think is that a stone or some detritus was picked up by the chain and carried into the sprocket area, to jam solid and crack the alloy.
So, I'm left with a bit of a gap in front of the sprocket, I'd leave it, but the engine will get splattered with chain lube, time to make up a shield and find a way of mounting it securely.
So, there you go. If there is one lesson to learn its that if a chain does snap, it WILL clear off your crank-case so look after your chain!
____________________
The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?

[monkeybiker]

pics

[jjdugen]

Closer inspection shows deep grooving from the chain in the bits of case still around. I put on a 17 tooth sprocket a while ago, looks like its a little too large. Also, the DID links are higher than the RK chain I had on before. I guess that the larger sprocket and higher links have been chewing away at the casing until it gave up.
Sorry, no photos, phone dead and camera faulty, (got soaked last weekend, died the death somewhere between Newark and Manchester).
____________________
The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?

[monkeybiker]

I put my wallet and phone in plastic sandwich bags if I need to make sure they stay dry.