Thank you both for your tips. I will definitely let you know how I do. It's all flat road so I think I will be ok. I am just worried seeing I have never gone this far and can just picture everyone finishing and there I am behind by an hour!.When I do ride distance rides with my husband we keep about a 15 mph pace so I am hoping I can keep it up for that long.

I feel more comfortable now. Thank you again for your advise.