Is anyone doing the elephant rock century ride? at most all I've ridden at a time is 40miles and It was fine but I ride about 20 to and from work every day. Is there any training I should do? maybe ride my fixie the 20 miles a day? or load up my touring bike and do some climbing?
Your fitness shouldn't be a problem. Just ride longer rides on the weekend so you get used to being on the bike for a long time. To simulate ERock, ride into the wind for a stretch near the end of your longer rides.