Danny said:
York-Scarborough or York-Whitby would both be good - but we might struggle to find anywhere that would open for a late night cake stop.
I guess there would be possibilities in both Malton and Pickering.
York to Whitby would be great. The A64/A169 route would be quick and simple but rather dull. I would hesitate to use the A64 even in the wee hours: it carries a
lot of lorries and there are some stiff climbs on narrow, twisty stretches: Golden Hill in particular has had a lot of deaths. There's less traffic at night, but that just means that what there is travels at even more insane speeds.
I would route it via Strensall, Sheriff Hutton (aka York-ish), Hovingham, Nunnington, Kirkby Moorside, then up Blakey Ridge. Wonder if we could get the Lion Inn to stay open? Blakey Ridge is a long climb, but a steady one, not a killer. Then Danby (avoiding Rosedale Chimney) and along the valley to join the A171 for a splendid descent into Whitby.
What could be a better destination than Whitby? The Abbey with the sunrise behind it would be skylined as you came down the hill. The harbour is as scenic as they come. The World's Best Kippers (it's official) are available from Fortune's (although it's a stiff climb to get there). My mate Joe runs a row of holiday cottages there for those thinking of spending the rest of the weekend there. Read
Dracula before you come. Or don't if you're easily scared.
This is a route I've used and it's fantastic. The moors at night are something special: it's very, very dark. There are supposed to be ghosts associated with the moor crosses.
The route gets a little complicated in Eskdale, unfortunately.
An alternative might be to go via Pickering, then on the A169, but I really wouldn't use the A64 to get there. There are alternative routes via, say, Sheriff, Castle Howard, Amotherby, Kirkby Misperton.
From Whitby, riders would have a choice of trains back to York, or could go on the Moors Valley line back to Pickering to make a day out of it. Pickering back to Malton for a York train is a flat, straight run.