Lovell or his mechanics came up with a two speed kilo bike.
tricky to describe, essentially two cogs of slightly different teeth, two cranks, think tandem.
the lower gear was the start, as the bike moved forward the second cog wound onto the hub, it hit the shell land and the other side broke free.

a potential trade off of excess drag but the lower gear allowed faster acceleration from a standing start.
as the race was about a minute, an interesting exchange.
the rules were soon tightened up