Road biking is very popular in Co Wicklow and lots of cyclists pedal their way uphill to Roundwood which is a popular stop off point to refuel in the local shops, pubs and café!
There are super mountain biking facilities at Ballinstoe Woods just 4km north of Roundwood village https://www.coillte.ie/site/ballinastoe/
Biking.ie are on site in Ballinastoe where you can hire a mountain bike, get lessons, book tours, get some excellent advice on the trails and much more. Check out their website for further information http://www.biking.ie/index.php