Originally Posted by
stevel610
Switching from a 28 to 24 will be (about) like adding 1 tooth to each cog your rear cassette.
No it isn't. A 28T chainring is nearly 17% larger than a 24T chainring, so it's like adding nearly 17% to the number of teeth to each cog in your cassette. Even for an 11-tooth cog, it's equivalent to nearly a 2-tooth addition. For a 24-tooth cog, it's like becoming a 28-tooth cog. For the 32-tooth cog that comes on a Trek Verve 2, it's like gaining about 5 teeth and becoming a ~37T cog.