Note that this is route is presented purely as a means of accessing Harborne Leisure Centre. The roundabout on the A4040 is hostile and poorly designed, and as a consequence has a high rate of collisions. Facilities for pedestrians are poor, and non-existent for cyclists. The junction needs a major redesign.
Harborne is one of the most difficult areas to get around by bike. This is courtesy of a hostile and bizarre road system that makes driving difficult too. It's made worse by anti-cycling measures, such as the cycling prohibition on Old Church Avenue.
Old Church Road is narrow and twisty, yet some motorists see it as a good place to travel at speed and overtake. To avoid it, try riding through Bishop's Croft. It would be nice if the Bishop of Birmingham could be persuaded to encourage people to walk and cycle along here. There is a gate at one end, but it is rotten and could be replaced with a half barrier gate, to create the required filtered permeability.
Willow Road and Raddlebarn Road are both far too busy with through motor-traffic, and need the Dutch filtered permeability treatment. However, this route segment is mostly quiet. Many cyclists (including myself) will prefer to use Willow Road, as it trades with-flow excess motor vehicles for the Sycamore Road / Laburnum Road junction, which is tricky whilst heading uphill.
BCC recently signposted this for cycling and made the path between Sparrey Drive and Raddlebarn Farm Drive shared use. Unfortunately Raddlebarn Road is unpleasantly busy with motor traffic.