Formerly one of the best if not the best roads in the area. Known as a mini-nurburgring it never really lived up to that billing but it did combine a lot of challenges with the opportunity to make good progress.
The challenges remain but it has been totally emancipated by almost blanket coverage of 50 and 40 limits. Some are possibly justified by hazards, others are clearly political.
It's still a worthwhile ride and nice to combine with a spin up the B645, just nowhere near as good as it was.
The northern section is really nice with lots of open bends and reasonable straights. Once south of Kimbolton, the almost constant 50mph limit spoils what could be a great bit of road.
If you're looking for a more circular route and for a good morning out, Start in Kimbolton, turn right into Station Rd. Head out towards Catworth taking in open field's but be aware of farm turning's and related traffic. On the otherside of Catworth caution over the top of the A14, as the east slip road junction is blind. Make progress into Old Weston, turning right into Winwick Rd. Some rough patching on this road but fantastic bends (and scenerey) all the way to Glatton, where turning right towards Sawtry. Note Addison Arms on right. Through Sawtry go over the top of the A1, good selection of roundabout's here but keep an eye out for the Law. Head out towards Abbots Ripton alongside the railway and then into the village. Turn left and follow into St Ives, straight ahead and out towards the A14. Go over the top and follow through Hilton, this brings you out at Papworth Everard, straight over and on towards St Neots. Follow signs for Higham Ferrers and this will run you back into Kimbolton. Very good couple of hours.
This is a great road combining everything from fast sections to 90 degreee corners and then finishes in Bedford for a nice cuppa in the town centre
Travelling south from Kimbolton you enter Bedfordshire almost straight away. The counties attitude to traffic calming is completely different from Cambs and this road suffers because of it. the topography is similar to the Northern half of the B660 but not much is left as national speed limit. On the bright side though as you get closer to Bedford there are some nice pubs for partaking of luncheon.
A nice long quiet run through some quite nice little villages, not exactly high speed adrenaline type stuff, but enjoyable nonetheless