My avatar is of the late Sheldon Brown, bike mechanic extraordinaire. He heralded from the pre-Youtube age. His ability to communicate via electronic text mechanic advice is rarely matched. He continues to be a great repair buddy earning a white ghost wrench in the heavenly garage helper called the internet.
Sheldon Brown-Bicycle Technical Information
A go-to source of information about bicycle maintenance, repair and customization
www.sheldonbrown.com