There's nothing in the SE area diary for April, so perhaps the Saturdays of the 13th or 20th of April? (Previous Urban RBs have always been held on a Saturday, due to the high attendance from those on the South Coast and scheduled engineering works on the railways).
Ah ha, I have finished my bike at last, I've have been looking forward to the next urban ride. I can make either the 13th or 20th, will wait to see which date is chosen.