For the last year or so my dad has been talking about doing a century ride. Last fall he got a new bike. So for his upcoming birthday my step mother is getting him a trainer, and I'm going to sign up him, my brother and I for a ride. Any recommendations for easyish rides in Colorado? I figure we probably won't do a full century this year unless it's a fall one. But maybe we can do just part of a century earlier in the summer or spring. Any ideas?