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bicycles and Sherman tanks

John Alroy writes:
> In response to Flying Goat's latest:
> >    Why did birds survive and not therapods?...
> 1) Birds are several orders of magnitude smaller than theropods were,  
> and this makes a HUGE difference ecologically; 2) Recent birds are  
> several orders of magnitude more diverse than theropods ever were  
> (there are about 9,000 named species of birds), and probably were  
> similarly diverse in the the latest Cretaceous; 3) birds are found  
> virtually everywhere on the planet, including all sorts of Pacific  
> islands inaccessible to terrestrial animals, which means that there  
> are/were plenty of refugia available to them. Put these things  
> together, and I think you will agree that birds vs. theropods isn't  
> really a meaningful comparison - it's like comparing bicycles and  
> Sherman tanks. 

I think that this comparison is quite appropriate.
1) Bicycles are far smaller than Sherman tanks, have much smaller energy
   requirements per distance traveled, and can satisfy those energy 
   requirements with a much more diverse source of fuel.
2) Bicycles are far more diverse than Sherman tanks.  There are many more
   manufacturers of bicycles and they produce many different models.
3) Bicycles are on almost all human habitable land masses. 

Although in a one-on-one encounter at design conditions, I'd rather
be in a tank, during environmentally stressed times, I'd much rather
have my bicycle.