Simon,
Excellent work on the train hire option, that looks like a real potential to have an annual FNRttC of epic proportions. Obviously the ride would have to meet the occasion and no doubt much planning with the movement of upwards of 200+ cycles through the night. I spoke to National Express Group Travel who were non forthcoming in accomadating huge numbers of cyclists, I will still contact their customer relations people. Hull Trains runs 5 or 6 daily direct services between Hull and Kings Cross, however they use 4 or 5 carriage trains with very limited luggage space for bikes, personally I think they would struggle with more than 10 bikes! Whether they could run a special remains to be seen, I suppose it's worth asking?
Grand Central operate from the North East (Sunderland) direct to Kings Cross but there last train leaves London KX at about 5pm arriving into York at about 7pm,a little early for the traditional midnight departure. Thequestion could be asked again as to a special? They do use a more conventional train with a proper luggage space.
I spoke to a coach firm and got quoted a price of £1400 for a 52 seat coach, with driver and including overnight accomadation for said driver. This was for a Hull to London and return trip, been a Hull based company, so it was just to get a rough idea, there is then the issue of transporting bikes as well, some coaches have huge luggage space under the seating space but probably not for 50 odd bikes. So some additional means of moving the bikes as well. Based on the quote, which may be cheaper from London to Hull and return it works out at about £27 each, if you were to factor in £10 each max to hire a 7.5 tonne truck and fuel etc it's not a bad price overall but it is a long journey to make.
Your rail hire option begins to look more appealing. Far-fetched idea in 2009 becomes reality in 2010?. Possible drawback could be huge FNRttC numbers after everyone gets a taste of it??