Originally Posted by EvilDoctorK
A little bit convoluted but it's the fastest way I think (and probably cheapest too - you can do it all on a Zone 2-6 travel card)
If youre talking about a one day travelcard then not at 7am on a weekday morning you cant... unless you buy the more expensive peak time one.
I travel from Hove and always do the Clapham Junction-Feltham-285 bus route when going to LHR. Its quicker than the tube and the bus goes from literally outside the station door, although you do have to cross the line first. Buses run about every 7 minutes i think and there are bus lanes most of the way to the airport so they dont often get stuck in traffic, and at 7am there won't be much traffic anyway.