Buying a Second hand bike is not at all a bad idea. Instead its a way of owning your dream bike. According to my views first of all consider the seller, how honest and transparent he is for selling, if he is too desperate then something is fishy. The main points of buying its second hand bikes is the engine clutch and gear . You can easily identify it by riding the bike for a test drive. The best way also to ensure whether the bike servicing is done up to date or not . Next see the tyres, the wear and tear is a important factor. And seeing the comdition of tyres you can easily identify whether the owner was good or bad rider.
So folks keep the above things in mind before buying a second hand bike.