The section from the Erith roundabouts to Willingham is a killer. VERY undulating Fen road. Too fast and it'll have you off your bike ....
Pull out of st ives following the A1123 along the needingworth bypass nice straight but beware the juncyion on the left half way along and the speed camera at the end. Follow the road through Earith, nice sweeping bends, At the roundabout do a right toward Willingham, along the riverside and sweeping bends into a straight for two miles, at the traffic lights do a left takes you through to Rampton road here you have some sweeping curves and plenty of blind corners with farm gates and hedges. Travel into cottenham and turn right at the green, nice friendly roads into Histon, turn right at the lights and follow the road to the A10. Follow the A10 into town
This is a great Saturday morning ride and avoids using the rubbish A14 to go into Cambridge.