Possible Clues:

• Minute hands, essentially
• They meet in the centre of the ring
• Small radiator touching two spokes
• Center-to-circumference lines
• Some area factors
• Cuts into a pie, often
• In a circle, they're all the same length, these bones
• r's, in math
• More than one spoke of Roger's plug on TV — two!
• More than one spoke of bones