Cassette range and gear jumps: two numbers, two different jobs
“Twelve-speed, wide range” tells you how many sprockets there are and how far the ends are apart. It leaves out the space between the gears where you spend most of the ride. Check both: range determines the available span, while the actual tooth sequence determines each step.
For a cassette alone, divide the largest sprocket by the smallest and multiply by 100. A 10–44 has 440% range; an illustrative 11–34 has about 309%. Keep the front ring constant when comparing their highest and lowest gears. For a double, calculate the entire drivetrain range separately because the front rings add another span.
Count the percentages between teeth
SRAM’s XG-1271 specification, checked October 4, 2026, lists 10, 11, 13, 15, 17, 19, 21, 24, 28, 32, 38 and 44 teeth. Its 11-to-13 step is larger in percentage terms than its 17-to-19 step, despite both adding two teeth. Divide the larger tooth count by the smaller, subtract one and multiply by 100. These percentages describe the increase in rear tooth count, not the decrease in the front/rear gear ratio.
Tooth-ratio calculations, not ride-test results
Step
Calculation
Rear-tooth increase
11 → 13
13/11 − 1
18.2%
17 → 19
19/17 − 1
11.8%
32 → 38
38/32 − 1
18.8%
Check the section of the cassette you live in
At the same road speed, moving to the larger rear sprocket increases required cadence by that ratio. In the illustrative 17-to-19 shift, 80 rpm becomes about 89.4 rpm, ignoring speed changes. Whether that feels useful depends on your pace and preferences; the table is not a ranking of cassette quality.
On a Twitter V3 Wheeltop EDS shopping list, request the exact cassette sequence as well as the derailleur model. The frame photograph does not identify the gears on a different seller’s build. Compare sequences only among systems approved for the actual drivetrain and hub, then choose the gaps that suit your normal riding.
For the climbing end of the comparison, use the distance-per-pedal-turn calculation. It answers a different question from the gaps between your cruising gears.
