XKCD Isn't Funny - #1673 - Timeline of Bicycle Design
Surreal humor is hard to review. If the joke was "how many bicycles does it take to change a lightbulb? Four!" I could explain how it seems like it was made up in fifteen seconds for the sake of an example and so on and yadda yadda. But when the joke is "How many bicycles does it take to change a lightbulb? Bicycles don't exist." the lines start to get blurry.
I'm a big fan of humor which is just bad ideas or lies given to the viewer straight-faced. However, this presentation strikes me as basically the worst way of getting that concept across. Its very static, very passive. Compare that to The Dismal Jesters (may it rest in piece), which had Jim actively trying to convince Jonathan to agree to his plan. Compare it to Monty Python's "How Not to be Seen", which has the presenter talking directly to the audience.
I want to make it clear that I'm not saying that this comic is unfunny because it isn't Monty Python. I'm arguing that were this comic to use a more narrative approach, like Monty Python often did, the comic would be stronger for it. While it is true that it would be harder to do in comic form, I think it can be generally agreed that the joke looses something in this timeline presentation, especially without transitions between the years.
That's another thing. The lack of actual progression from design to design. The comic is labeled "Timeline of Bicycle Design" but it comes off more as just 'several ideas I had for very bad bicycles'. The bicycles don't follow from each other, except maybe for the last two.
Also, I know that its part of the joke, but only about half of these are bicycles if we go by the 'two wheels' definition.