Originally Posted by
Aviatrix
Alternatively (to save some time) how about using the luggage storage facility at Paddington instead? Take a taxi to Paddington in the morning, drop off bags, take public transport to Paddington in the afternoon, jump on the train.
The left luggage facilities at both LHR and Paddington are prone to very long delays (read: queues). I wouldn't recommend either if you're short on time, and I'd rather brave the tube with a 28". Just put on a pair of white trainers and a baseball cap and barge on, althought regular passengers on the Piccadilly Line would be more familiar with that sort of behaviour than those on the Jubilee and Bakerloo lines.