You can follow some of the route taken by the professionals, the Tour of Britain comes through Builth Wells.
At the heart of some of the National Cycle Routes, Caer Beris is the perfect base to explore the surrounding countryside.
Route 8, known as the Lon Las Cymru, is the main route from north to south in Wales and can be explored in both directions. Details HERE
Route 43 is a section from Builth to Llanwrtyd but will eventually link with the Celtic Trail in South Wales. DetailsHERE
Route 825, The Radnor Ring, just north of Builth, takes you along the Welsh borders on a mixture of roads and lanes. Details HERE
There are almost too many trails to mention, so you will never be short of somewhere to try.
The Epynt Way is a circular route but can be done in easy stages. It is well marked and goes around an army training ground. Details HERE
The Elan Valley has some wonderful trails with the Victorian dams as a backdrop. there are four main routes. Details HERE
There are many websites which list suggested routes around Builth Wells. This one, for instance, lists 107 of them! Details HERE
If you are into competitions, one of the major events takes place in Builth Wells. A stage of the the Scott MTB Marathon series takes place in Builth on an annual basis. If you really want to test yourself, sign up for it. Details HERE