"Serious" has connotations that upset a lot of people when describing/separating cyclist types. How about a new term that is less negatively loaded*, but encompasses more varieties of cyclists?
One can be:
- Committed to an optimal cycling regime to maximize gains in the pursuit of going farther and faster
- Committed to maximizing their enjoyment of cycling without the overhead and distraction of Watts, training effect, CdA and Crr, etc., etc.
- Committed to looking sharp on the bike within the accepted fashion style of their discipline
- Committed to looking casually incognito such that nobody would know that they were on a bike once they hop off one
- Committed to riding on the best equipment they can buy with their hard-earned money
- Committed to extracting the maximum amount of utility with the absolute minimum amount of monetary on investment
- Committed to the aesthetic of their preferred time period of bikes
- Committed to being their own mechanic and being self-sufficient at home and on the road
- Committed to keeping their bike shop in business because there are more important things to invest their time and knowledge into
- Committed to riding in whatever conditions the weather and seasons throw at them
- Committed to not ever needlessly suffering through inclement weather
- Committed to not letting hostile traffic conditions keep them from riding where and when they want
- Committed to maintaining their sanity by avoiding traffic hell
What makes an uncommitted cyclist? I would say anyone who has no relationship with a bike, no part of their mind or heart taken up by bikes. Someone who couldn't care less about maintaining their bike, wouldn't be bothered if they never rode it again, doesn't think about it once they're done riding it. And simply, someone who wouldn't label themselves committed or care that others would call them uncommitted.
In that last sense, anyone who takes personal affront at not being consider a "serious" cyclist would by definition be considered personally invested enough to be a committed cyclist.
*: One connotation for "committed" that I intentionally am fine with is the level of obsession that non-cyclists would perceive to be worthy of professional psychiatric help, because yeah...