"John Doe" wrote in message
news
Thinking about turning the crank of my bicycle with a wire
spring. Approximately, how thick will be spring wire need to
be?

https://youtu.be/oAj1F5fSGWI

The spring will be placed between the drill and the hub spindle.

Thanks.

http://www.plantengineering.com/sing...ebbdc3224.html