Originally Posted by
chaadster
Well yeah, I’ve got a SRAM Force AXS drivetrain with a 48/35 crankset and 10-33 cassette, and I roll either 35c or 42c rubber, so none of the gear combos actually move the bike the same distance per revolution (i.e. in terms of inches of development) they are all distinct, and that’s what’s important.
26 gears?
I'm guessing you have a 12 speed 10-33 cassette, so you start with 24 total gears, not 26. There are 3 nearly identical gear ratios (0.6%, 1.1%, and 2.1% diff) and 3 darn close gear ratios (2.8%, 2.9%, and 3.3% diff). So, unless you want to do some painful double shifting across multiple gears to access them, you really have 16 useable gears in the best case scenario.
From highest to lowest, they are:
48/10, 48/11, 48/12, 48/13, 48/14, 48/15, 48/17, 35/13, 35/14, 35/15, 35/17, 35/19, 35/21, 35/24, 35/28, 35/33
Originally Posted by chaadster
Sure, a couple of the gears are very close— in terms of gear inches, only 2 ratios are “the same” w/ 35c (or 25c, for that matter) and none are the same w/ 42c— but that’s entirely the point of having many gears, the ability to fine tune gear selection to maximize the rider’s effort.
Gear ratios don't change with tire width. If two gear ratios are the same with 35c tires, they're the same with 42c tires.