Rear Tyre Scoring

Hi guys, been on holiday and left the bike at a mates so he could run it while i was away. He only lives about 7 miles away but when i rode it back i noticed scores on the left side of my rear tyre where a rather large chicken wing used to be. As i'm not very mechanically minded i'd rather get it checked out before i ride again, bikes a k8 and still under warranty so maybe a trip up to cupar is whats needed. Any ideas on what could have caused this?

[Stu]

Originally Posted by jaromic

chicken wing

You mean chicken strip

Pop a piccy up of the scoring. You'll get a better answer that way.

[Red Herring]

Is the rear tyre still properly inflated ? (not sure how long it's been standing)
Is there a possibility something has fallen down between the wheel and swingarm. It wouldn't be the first time a stored bike has been used as a shelf and something small has fallen into a nook somewhere.
Rear wheel alignment/chain adjustment? Can they possibly be so far out they are meeting each other?
Did your mates definition of "run it" include doing doughnuts!!

My rear picks up marks exactly as you describe just from spinning the back wheel, whist its still on its side stand, when washing the bike.

These dissapear on the next ride.

But if you post a pick, it would definitely help.

Cheers,
Carl