The London course is mostly on Brand's Hatch - which is a lumpy race circuit (think they used to hold the F1 there, now used for motorbike racing). Wind conditions likely to be variable (but it's a twisty course so it's gonna hit from all angles).
Brands Hatch has 2 layouts, the Indy sprint circuit and the longer GP circuit.
I've never done it on a bicycle but have tons of trackday experience there as it was my local circuit for 8 years. There are two places I can imagine would be braking points on a bike
1. Into Druids hairpin, although this is uphill so you may be able to scrub speed here
2. Graham Hill bend coming down the hill again from Druids
On the GP circuit
In addition to the above, Surtee's is uphill so that should be fine. Stirlings would be the only other point as that's a downhill 90 degree left but the track's pretty wide there
Paddock Hill should be a blast on a bike at top speed
Best of luck