You're probably largely right. I tend to be a back of the packer in 5K's and 10K's as a jogger, too. I guarantee that a better bike would shave some time off of a 100K or century for me, but the bike I own is perfect for most of my needs and is definitely capable of going the distance. I'll never be one to be concentrating of my cadence when I'm out on a beautiful country road that I may never have the opportunity to be on (on a bicycle) again.

Brian