From the A40 take the B452 turn-off towards Ealing (actually signposted as Perivale) along the Argyle Road. Pass through a set of traffic lights and across a roundabout. At the second roundabout, (about 0.5km) turn right into Vallis Way. Trailfinders Sports Club entrance is at the end of the road.
Either take a train from Paddington to Ealing Broadway and then a bus. Or take a train from Paddington to Castlebar Park, cross over the bridge and walk
Many buses stop in the vicinity of Trailfinders Sports Club, including the N7, 297, E1, E2, E7, E9, E10 and E11.