Did this route whilst back in the UK doing my lessons & test, a pretty nice road really.
The start is excellent weaving between the hedges without any farm enterences, if it has been raining recently then watch out for streams on the hilly sections.
Out of Birstwith the roads are fast and sweaping but keep an eye out for side roads, with occasionally have gravel on them.
BE SURE to turn right at the junction in Hampsthwaite then just follow the road.
At the end of the run you can go to Darley and head towards Patley bridge, with also has excellent roads