Mach 2 is the 'middle-Mach, taking you steeply upwards and wickedly fast downwards - a great test of your skills'.
This route takes you South East out of the town along the river Dulas and across open farmland where you ride along Glyndwr's Way, made famous by the first Prince of Wales, before dropping down to Talbontdrain. A steep climb up to the forest is followed by a long flowing descent to Bryn Coch Bach, and then the final descent of Mach 1.
More information can be found here: http://www.dyfimountainbiking.org.uk/