You don't mention the brand of bike but I assume for £10K its a fairly new model. Check the manufacturers warranty, for instance, the standard for a BMW is 2 years and automatically transfers to a new owner. Most bikes these days have a forum based around them, so as Gerry says, get on there and do your due diligence on the owner as well as the bike. Try and get someone who knows that particular bike well to go along with you for an opinion if you're not confident to do that yourself. And remember there's always another one around the corner so walk away if your gut tells you to.
