Bit of an old thread, but lots of relevant stuff. I'm planning a one-off trip into Little Abington from the south west (I could come via Fowlmere or maybe Duxford, but south of the A505 is hillier). Looks like there's a route from Thriplow to Whittlesford, and then pick up the A505 path discussed above? Presumably it underpasses the A505 at the TL515489 minor road bridge? The alternative seems to be a long bridleway from Great Chesterford to Linton, but that's bound to be muddy and I'll be on a road bike, though not with lightweight tyres. And again, Great Chesterford from the south west means more hills than the more northern route.