The below information was received from TFL;
On Saturday 3 and Sunday 4 August, roads across London will be affected by a weekend of Prudential RideLondon cycling events.
Road closures will be in place in Westminster from Friday 2 until Monday 5 August. Central London will have significant road closures from 05:00 until 18:00 on Saturday. There will be road closures across east, central and south west London as well as some parts of Surrey between from 04:00 until 20:00 on Sunday.
Delays are expected, so avoid driving in the affected areas unless absolutely necessary. If you need to drive, please allow more time for your journey. Some bus routes will be on diversion and stop short of their normal destination due to road closures over the weekend. Many central London bus routes will not serve their usual stops.
Use Tube and rail to get around London more quickly, and consider walking for shorter journeys