With spring fast approaching, that means the opening round of the 2011 Chain Reaction Cycles MTB Marathon Series is just four weeks away.

As has been the case for the past seven years, the Exposure Lights Big Night Out kicks off the series in style at Penmaenau Caravan Park in Builth Wells on April 10.

The 43km night marathon, with approximately 1,105m of climbing, will be followed on the Sunday by the Spring Marathon, with 31km (800m of ascent), 53km (1,450m) and 75km (2,150m) route options available. Full course details can be found here.

Riders tackling both the night marathon and Sunday’s race will receive a £15 discount and have been promised varied, challenging courses.

The series has five dates, including new locations in Llandovery, Wales and Marshbrook, England, and entries can be made online here.