Pre-race drinks??? Exactly how are you training? ;o)
Whereabouts are you going to be staying?
The Raven Inn at Llanarmon yn Ial is a community run freehouse and worth a visit. But then so are lots of pubs around the Llanferres / Loggerheads area. "We Three Loggerheads" is probably the busiest and closest but not necessarily the best. I can't think of one that doesn't do real ale.
I always think real ale tastes like something strained through old mens socks so I'm not very knowledgable on the subject. Probably best if you do your own research on villages in the area.
Llanferres, Loggerheads, Maeshafen, Gwernymynnydd, Cilcain, Llanarmon yn Ial
Let me know if you need any other information - I'm better on other subjects.