London to Brighton shared transport from the Midlands

I realise it isn't a serious event but three of us have agreed to do the BHF London to Brighton bike ride on 19th June this year and have only now realised that it is going to be a nightmare getting to the start!
Is anyone else on the forum doing this event and if so, are there any spaces on transport from anywhere in the Midlands to near Clapham Common on the day?
Obviously we would be happy to share costs.
Thanks