Genetics is a huge factor in athletic ability, it sets every human at a different level and there is nothing that can be done about it, we all can not be olympic athletes or pros. Also unless you know the age etc. of others you are riding with, then it is silly to feel bad about them outpacing you. I am retirement age, so there are lots and lots on road bikes I will never be able to keep up with, so I just am happy with being able to go as fast as I did last year, Father Time and Myself are my only real opponents. If I switch bikes it can make some little difference, so that is another opportunity to have fun, setting PRs on specific bikes, how fast you can do a familiar ride on this bike or that. Winter is setting in now and with all the baggy clothing and dense wet air the season for PRs is over, and I have to face the fact that next season when it warms up I will be another year older and slower, but as long as I can still ride then I am already a winner, lots can't do it no matter what for various reasons. Lucky us.....