No I'm not talking about BenRidin's avatar
I was cleaning my drivetrain yesterday when I wondered exactly how many teeth are on all my chainrings and cogs. It turns out the answer is 261.
Front: 86 (36-50)
Rear: 175 (12-13-14-15-16-17-19-21-23-25)
I suppose you could also add 20 more for the two wheels in the rear derailleur for a total of 281 but that's kind of a constant on derailleur geared bikes (unless some derailleurs don't use 10 tooth wheels?)
One thing I found interesting is that I was considering putting an 11 cog on my cassette. This would actually lose me 5 teeth because I'd change out the 12-13-14-15-16 gears for 11-12-13-14-15.
The other thing is that tall gearing in the front increases your tooth count but so does granny gearing in the rear so there's no real direct correlation between number of teeth and gear ratio ranges. Of course fixies and single speeds are a whole other ball of wax. And unicycles and high wheel bikes are yet another
Not sure what this info is useful for but it made me wonder what gearing other people are using and how many teeth they have.