I'm leaning towards the Dover ride at the moment, it should be flatter than the Lancaster ride (I think no route posted that I could see) and in that case I definitly think you should do the metric Issac (I'll want company). As long as you pace yourself I don't think it should be an issue, you'll be beat at the end but that's part of the fun lol. (ok really if you don't think you are upto it that's fine I just think it would be fun)