I do not race on the roads (obviously, a club TT or hillclimb doesn't count). I think it is perilous to exceed a safe speed on the public highway.
Nonetheless, I have observed the following absolute laws governing the relative speed of cyclists:
1. If someone passes me, he or she is taking it all WAY too seriously and has probably just left home and is only riding a few miles.
2. If I pass anyone (which one day I hope to), they will certainly be on a training ride for the World Hour Record, even if that happens to be the World Hour Record (Women, 80+).
3. In any conditions I have EVER ridden in the bicycles ridden by all other cyclists are much better suited to speed than my own. For example, a toddler's tricycle presents a low-drag frontal area and a rod-braked shopper ridden by an aged widow offers weight advantages on those fast descents. If it's rained in the past fortnight, a
Halfords Apollo full-sus MTB offers grip advantages over a lightweight alloy road bike, so will be faster on flowing A-Roads.
All of the above are empirically tested and shown to be right.
Also, you can only scalp me if I agree to race, so to the rider who 'thinks' she got me this morning, it doesn't count and anyway your mum was pushing you and those stabilisers would be banned by the UCI.