George and Lynne are out for a walk. George notices a woman on a bicycle and tells Lynne that it is Pam. Pam greets George and Lynne and tells them that she and Henry have laid up the car and bought bikes. She adds that they've gone green. As a man on a bicycle comes into view and George says that in Tom's case, more like red.
It seems as though George and Lynne have quickly moved to the side of the road to let the impending cyclist past. It's as if just before we join the story George has said “Jesus, who's this crazy cyclist tearing up the road? Quick Lynne, get out of the way.” Luckily it's Pam.
When she says that she and Henry have laid up the car, she must mean that they have put it away. Unless it means they have sold the car for bikes, which is either a terrible deal or they have a lot of extra cash now. It could mean that they just sold the wheels to buy bikes and now the car is laid up on bricks.
Pam talks of her and Henry riding bikes, so who is Tom? And what is he doing cycling with Pam? Tom is the local pervert. Everyone knows him and he follows different women around. In order to blend in when following Pam, he has had to start cycling. It has made him out of breath. Seeing Tom is a little bit of a shock to Pam who didn't realise she was being followed. Tom has had to ride past to pretend he was on his normal cycle ride.