Complete Guide to Cassette Gear Ratios: 11-28 vs 11-30 vs 11-34

Cassette Gear Ratios: Every Tooth Is a Strategy

If the chainring sets your “big picture” gearing, the cassette is the key to fine-tuning your cadence across different terrain. The arrangement of 11 or 12 sprockets on a cassette directly affects whether you can maintain an optimal pedaling rhythm across varied ground.

Overview of Common Cassette Configurations

Shimano 12-Speed (R7100/R8100/R9200)

Model	Tooth Sequence	Best Use
11-28T	11-12-13-14-15-16-17-19-21-23-25-28	Flat-road racing
11-30T	11-12-13-14-15-16-17-19-21-24-27-30	All-around
11-34T	11-12-13-14-15-17-19-21-24-27-30-34	Climbing-oriented
11-36T	11-12-13-15-17-19-21-24-27-30-33-36	Mountain routes

SRAM AXS 12-Speed

Model	Tooth Sequence	Best Use
10-28T	10-11-12-13-14-15-16-17-19-21-24-28	Flat-road racing
10-30T	10-11-12-13-14-15-17-19-21-24-27-30	All-around
10-33T	10-11-12-13-14-15-17-19-21-24-28-33	Climbing-oriented
10-36T	10-11-12-13-15-17-19-21-24-28-32-36	Mountain routes

Tight vs. Wide Spacing: The Core Trade-off

Tight-Spaced Cassettes (e.g., 11-28T)

Pros:

• Small jumps between sprockets (mostly 1-2T), so cadence barely interrupts when shifting
• Easier to find the “perfect” gear
• Great for steady output on flats and gentle grades

Cons:

• Largest sprocket is only 28T, which may not be low enough for steep climbs
• Narrower overall range means less flexibility for varied terrain

Wide-Range Cassettes (e.g., 11-34T)

Pros:

• The 34T sprocket gives you a strong low gear for climbing
• Wide range lets a single cassette handle many types of terrain
• Paired with a 34T inner ring, you can reach roughly a 1:1 ratio

Cons:

• Larger jumps at the big-sprocket end (e.g., 27-30-34) create a noticeable cadence shift when changing gears
• The mid-range may be missing a few ratios you use often

Jump Analysis: The Devil Is in the Details

Using Shimano 12-speed as an example, compare the shift patterns across cassettes:

11-28T jumps: 1-1-1-1-1-1-1-2-2-2-2-3
→ Extremely tight in the first half — ideal for fine-tuning cadence on flat roads

11-30T jumps: 1-1-1-1-1-1-1-2-2-3-3-3
→ A balanced option — still tight in the mid-to-high speed range, with reasonable buffering at the big-sprocket end

11-34T jumps: 1-1-1-1-1-2-2-2-3-3-3-4
→ Slightly less density at the small-sprocket end, but the 34T’s climbing capability is a clear upgrade

Cassette Recommendations by Taiwan Terrain

Riverside Bike Paths, Western Coastal Flats

• Recommended: 11-28T or 11-30T
• Why: Nearly all flat, so a tight-spaced cassette gives you precise cadence control
• Best paired with: 52/36T chainrings

North Coast, Northeast Coast (Rolling Coastal Roads)

• Recommended: 11-30T
• Why: Frequent short rollers — 30T is enough, and the tight-spaced section maintains cruising efficiency
• Best paired with: 50/34T or 52/36T

Yangmingshan, Fengguizui, County Road 106

• Recommended: 11-30T or 11-34T
• Why: Moderate climbs — 30T is enough for most riders, but 34T is a safer choice if you’re less conditioned
• Best paired with: 50/34T

Wuling, Hehuanshan, Alishan

• Recommended: 11-34T or 11-36T
• Why: Long sustained climbs — a big cassette is your safety net
• Best paired with: 50/34T or even 46/33T

Round-Island Touring

• Recommended: 11-34T
• Why: Round-island terrain varies widely, requiring the broadest possible gear range
• Best paired with: 50/34T is the standard round-island setup

The Relationship Between Speed and Cadence

Using a 700x25C tire (circumference roughly 2.1m) as an example, here’s your speed at 90rpm in various gear combinations:

Chainring/Cassette	Speed at 90rpm	Use Case
50T/11T	51.5 km/h	Full-effort descending sprint
50T/15T	37.8 km/h	High-speed flat cruising
50T/19T	29.8 km/h	Easy flat cruising
34T/25T	15.4 km/h	Moderate climbing
34T/30T	12.9 km/h	Steep climbing
34T/34T	11.3 km/h	Survival mode on very steep climbs

12-Speed vs. 11-Speed: What’s the Difference?

The biggest benefit of upgrading to 12-speed is gaining an extra sprocket within the same overall range:

• The tightness of an 11-speed 11-30T is roughly comparable to a 12-speed 11-34T
• 12-speed lets you have both a wide range and reasonably tight spacing at the same time

This matters a lot for Taiwanese riders: in the past you might have struggled choosing between 11-28T (tight-spaced but not low enough for climbing) and 11-32T (low enough but with large jumps). Now, a 12-speed 11-34T solves both problems at once.

Practical Notes on Swapping Cassettes

Things to check when changing cassettes:

1. Freehub compatibility: Shimano 12-speed requires a Micro Spline freehub; 11-speed uses an HG freehub
2. Rear derailleur capacity: Confirm the maximum cassette size your rear derailleur supports
   • Shimano RD-R7100: max 36T
   • SRAM Rival eTap AXS: max 36T
3. Chain length: Moving to a bigger cassette may require a longer chain
4. B-tension adjustment: Larger cassettes require adjusting the rear derailleur’s B-tension screw

Cassette Weight Comparison

Cassette	Approx. Weight
Shimano 105 11-28T	345g
Shimano 105 11-30T	355g
Shimano 105 11-34T	385g
Shimano 105 11-36T	405g
SRAM Rival 10-30T	370g
SRAM Rival 10-33T	390g
SRAM Rival 10-36T	415g

The weight difference mainly comes from the larger sprockets added. For most riders, a 30-60g weight difference matters far less than having the right gear range.

Key Takeaways

Core principles for choosing a cassette:

1. Better to have more range than not enough: A big sprocket you never use beats needing one you don’t have
2. Think about it together with your chainring: A cassette shouldn’t be considered in isolation — calculate ratios with your chainring combination
3. Consider your most common routes: Choose a setup that covers over 80% of your typical riding scenarios
4. With 12-speed, take advantage of wide range: Since 12-speed already gives you a tight-spacing advantage, feel free to go with a wider-range cassette

Taiwan’s terrain features many “short but steep” climbs — even if you mostly ride on flats, the occasional bridge ramp or small hill still calls for a low gear in reserve. That’s why 11-30T is the safest all-around choice for riders in Taiwan, and if you head into the mountains often, go with 11-34T without hesitation.

Related Reading

• Choosing Climbing Gear Ratios: A Complete Breakdown of Compact vs. Standard
• Guide to Bicycle Gear Ratio Selection and Drivetrain Pairing
• Gear Ratio Choices for Climbing Races: Pre-Race Chainring and Cassette Setup Advice
• Road Bike Chainring Pairing 101: 50/34 vs 52/36 vs 46/33