The southern half of this route is an unmarked farm/country road with farm debris, gravel/grit, and is very uneven in places. Getting above 30 for any length of time on roads with so many blind bends, and tractor/van hazards is a real challenge.
That said, the northern half is simply spectacular! The road surface is pretty good, and the views of the Black Mountains etc are unbelievable.
Route is definitely worth a run, but maybe attempting from Hay on Wye will enable you to appreciate it more as the views are better down the valley.
As stated in other reviews, this is definitely a road of two halves - the southern part is narrow, windy hedge-bound. Wouldn mind missing it to be frank. But it all becomes worth it when you climb the mountain then pop out onto the north-west face of the ridge. What a view! On a nice day like we were lucky to have had (Easter Monday, 2009) its amazing.
The southern half was quite hard work, being a narrow little lane full of blind corners and gravel in the road. Also lots of walkers, cyclists and farmer types. The Northern half of this road is just fantastic. Really open mountain roads and absolutely fantastic views for miles. Highly recommended, but too bumpy and windy for sportsbikes to get going. Well worth a visit though.
Minor road over the Black Mountains. Pop into Llanthony Priory for a drink. Road is narrow tight and twisty first half and once at the top opens out to spectacular views. Often used on Top Gear for helicopter shots of flash motors.