42x16 the same as 46x18?
 

Ok showing my stupidity, but I wondered if these two gear combos were the same since they were both two apart on each. thanks:o I would guess they are the same..

divide 42 by 16. then divide 46 by 18

70.9 vs 69 gear inches. Just under 1 gear inch of difference. So in reality, they'd be quite similar, if indistingushiable even.

They aren't identical, but they are close. 46x18 is 67.4 gear inches. 42x16 is 69.2.

Check out: Sheldon Brown's Gear Calculator

47x18 would be closer. also your logic is flawed; it's a ratio so you need to divide between chainring and cog, not add/subtract. adding 2 teeth front and back does not preserve the same ratio. http://software.bareknucklebrigade.c...it.applet.html is what i use.