Related Clues:

• What a bald tire lacks
• From surface of tyre, study this?
• Pattern of tire ridges
• Walk with energy along Dart upstream
• "___ lightly"
• Tramp with the characters in theatre adaptation
• It's full of grooves
• Traction aid on a shoe
• Two-pronged attachment to a boat, for securing ropes
• Spike on a sports shoe
• Spike on a soccer shoe
• Put foot down: student finally to study
• Close to aghast having taken in what's on Pirelli?
• Soccer shoe protrusion
• Free trade: put your foot down