Arrrrgh, you are right. Look at these.



Doesn't look so bad huh? But look at this.



I gotta gaps, you see? This wear is done in 3-4 months. Puts a shoe into my month, really.

Too bad, but it ain't no Sugino Gigas or something; I didn't pay much for it. I swapped to a steel one just now. I suppose an aluminum cog is "viable" but it isn't a good solution.