Stats: 22 miles and 2439 feet of ascent
Nearby Brecon has all that you need, including The Bridge Cafe, a great spot to chill out, which also does bed and breakfast.
The terrain is rideable in all seasons but beware in bad weather conditions.
The Gap takes you up to 600m above sea level and is very open and windswept. It is essential to take food, adequate clothing and tools before you attempt this route.
Technically, the going is mostly straightforward, with a tricky ravine halfway up the Gap road and some big rock steps on beginning the descent from the Gap itself.