The event, run by the British Heart Foundation, starts in Clapham at 6am tomorrow (Sunday, June 19).
The route takes riders between Crawley and East Grinstead, by Haywards Health, Hassocks, and Ditchling, before finishing in Madeira Drive near Brighton Pier.
5.30am – 2pm: Chapel Road, Redehall Road and Antlands Lane – closed
5.45am – 2.15pm: Effingham Road, from Keeper’s Corner to West Park Road – closed
6am – 2.30pm: West Park Road to Dukes Head Roundabout – closed
6.30am – 4.30pm: B2028 and North Street in Turners Hill – one way southbound system in place
6.30am – 5pm: B2028 to Summerfield Lane via Ardingly – one way southbound system in place
6.30am – 5.30pm: Oathall and Hazelgrove Road, from Oathall Avenue to Sussex Square roundabout – one way southbound system in place
6.30am – 5.30pm: B2112 from Rocky Lane to Folders Lane – one way southbound system in place
6am – 5.30pm: B2112 to Ditchling – closed
6am – 6pm: Northend Lane to Beacon Road, over Ditchling Beacon to Coldean Lane – closed