Originally Posted by
pdxtex
Really, how do you know? Other sports have benchmarks that show your relative skill level. Can you run a mile in 6 minutes? Well you are probably a good runner. Can you do a kickflip? Well you are probably on your way to being a good skater. Oh, you can go down that black diamond? You get the point. So what makes a a cyclist "good"? Or accomplished? Doing a century is great, but if you have all day seems like anybody with relative fitness could finish it. So what, are some realistic bench marks that separate the athletic and skilled cyclists from everybody else? Do I have to ride up some 20 percent grade or be able to ride 40 mph?
You can pull out arbitrary milestones for cycling as well. Running a mile in 6 minutes suggests a level of fitness, so how about cycling a mile in 3 minutes? 2:30? 2 minutes? Climbing a 10% grade, 15% grade, 20% grade, then you can quibble over how long the hill has to be to count, and so on.
With sports that require specific skills (I'm thinking primarily martial arts but things like the kickflip you mentioned sounds like a very specific skill) you can measure based on a collection of abilities. With anything that's fundamentally about moving yourself from one place to another you've got such a continuum of speeds, distances and terrains it's largely irrelevant to try and argue that a particular level counts as "good".
You might arrange a comparison that could conclude that rider A is stronger or faster than rider B but that's about as far as you can go.