### Clue: Shattered bike racer swallowing tablet – it relieves tension (10)
### Answer: ICEBREAKER 
 ### Explanation: Definition: it, relieves tension
  **Anagram of**(shattered) BIKE RACER **containing**(swallowing) E(abbrev. for the drug $$e$$cstasy which comes in  tablet form).  Grim surface refering to athletes taking drugs.
Defn:  That which breaks down the tension amongst strangers at a party, bar or even a business meeting.  Could be a chat-up line, a party game, or even a "Aren't we having nice weather today?".  Though nowadays, with certain people at certain venues, it might well be a tablet.