No, I'm not starting a thread about # of teeth vs. top end gains, or low-end torque, or overall performance... rather, I'm interested in knowing about what they're made of. It seems these days sprockets are often made of aluminum... but I struggle to see an advantage, considering aluminum is so much softer than steel and would wear so much faster. Apparently some sprockets are aluminum core with steel teeth. Sounds good (I guess) but why not just make 'em 100% steel? Steel, aluminum, steel/aluminum hybrid sprockets... what's it all about I wonder?
