Im 63 and didnt take up group riding until last year. I can hang with the c's and b's but get my butt kicked alot of the time by the a's. I dont worry about it and neither should you. I do try to learn from my mistakes and one thing I do is try to hang to the rear of one of the better riders and do everything they do but take long pulls. I try to stay as tight to them as I can. Of course things happen and I frequently end up riding in by myself.