Good advice from everyone here. The metric centuries that I've done: first one I found a woman who was riding my pace - we finished together, second one - rode with various people throughout ride and finished by myself, 3rd one - found a group of guys that I could keep up with and finished with them. It's about the journey and the ride YOU want to do. Start off together and go your seperate ways if necessary.
"You can't get what you want till you know what you want." Joe Jackson
2006 Cannondale Feminine/Ultegra/Jett
2012 Trek Speed Concept 9.5/Ultegra/saddle TBD
My SO is SUPERMAN. Literally. He has done the police olympics both on the road and mtb, ridden on the USPS masters cycling team, is a police biking instructor, and on his worst day is tons faster than I am on my best day, and I am a pretty aggressive rider. However, he doesn't THINK he is superman. He thinks everyone should be able to keep up with him. He nearly killed a bunch of bike cops taking one of his bike courses....he played follow the leader with them and took them through the sand volleyball pits a few times. Few of them made it out.
Although he is NEVER critical of me, and protests otherwise, I know he would rather than ride with a group of faster men than with me. I can't pull for him, so he may as well be on his own, and when he pulls for me he has to go slower than what he finds comfortable (uh, that would be faster than 22 mph and maintaining 22 mph for 75 miles is not a possibility for me).
So we go together, gear up together, start off together, then I ride my ride, and he rides his. If it is a ride where we don't want to just hang around all day, I will ride a 100k and he will do the 100 miles....I generally get in about 45 minutes before he does on that....or he brings a book and waits for me to finish the 100 miles.
I find a zen spot riding on my own. I have made new friends, and I listen to my ipod (one earbud) and clock along at my own pace, hammer when I want, coast when i want, and all is well. I would probably increase my time if I had someone to share the work with, but oh well.
Give him a kiss and tell him to leave you and you will see him at the end.
And, on the MTB, I tell him NOT TO WORRY ABOUT ME. He can power through a lot of stuff that I pick my way through. I usually find him up the trail, clipped in, hand on tree, having a breather and waiting on me. It works for us.