I've got a 2nd hand 2001 zurich, in the last 3 years I've put on about 3k miles. Never had the wheels or headset worked on, the bike runs smooth, except for a very infrequent clicking noise when I pedal. Would you recommend that I get the wheels and headset serviced or should I leave it alone and just keep riding. I did check the wheels this winter and they were spinning smooth. Thanks in advance for your response.