Well done! Great feeling of achievement, isn't it. I've done many centuries and MS150s, but my wife with me on our Co-motion Primera tandem did her first metric century on Feb 26 and a full century on Mar 11. We averaged 13mph and had absolutely no after-effects apart from a feeling of elation. Oh, and by the way, we have raised over $5000 for the American Lung Association for that century. We are 65 and 66.