(08 Oct 2017, 8:15 pm)nk55 wrote It goes way back when it was the 724, something to do with arriva not running a Sunday service on the 6 or whatever number it was back then. So the 724 was diverted via new elvet and its run that way ever since.
There is a Sunday service on the 6 now, but the X21 still runs that way. I think it would be sensible to run it via Neville's Cross at all times just to simplify the service.