Apllying the brakes and rocking the bike forward, I can definitely feel a 'clunk' in the stem area which is a quill type. Neither the through Allen bolt has been removed, and neither have the locknuts or adjustment been touched. I'm selling the bike in the next day or so, so I don't want to throw too much at it, but neither do I want to sell it as a 'lemon'. What's the likely cause of the problem? Is it just a case of adjustment or are the bearings likely to be shot? Unfortunately, I don't have sockets of the size needed. I'd like to be able to tell any buyer what the problem is and then negotiate the price to account for any repair/check that might be necessary. Advice appreciated.