Gear Ratios page receives major overhaul

Many gearing options have become available since the Gear Ratios page was written in 2016 that make it easier to get lower gearing on road bikes. This includes super-compact gravel cranksets, 12-speed systems, and single-chainring setups. I therefore re-wrote the page to be clearer and include all of the latest options including extensive tables of all useful cassettes.

Read the completely re-written page here: Gear Ratios for Bikepacking & Ultra-Distance Cycling.

The part that took the most work is two new tables showing the best 11-speed and 12-speed cassettes with a gear range of at least 260%. I found 34 models across 6 brands, of which 20 merited inclusion in the tables. I include that whole section below and welcome comments about missing or incorrect information or ideas of how to improve it.

Cassettes

The two tables below include 11-speed and 12-speed cassettes that meet certain criteria and were available in late 2019.

Firstly, because large chainrings can be 55% bigger than small chainrings (e.g., on a 46-30 crankset), a cassette with a gear range of at least 260% can be sufficient to obtain a complete gear range of 400% when two chainrings are used (which was a reasonable range determined by the Low Gears and High Gears sections). Therefore, 260% is chosen as the minimum gear range to be included in the table. For a discussion of the merits and issues with single chainring setups, see the new One or Two Chainrings? section.

How tolerant different people are to gaps between gears was discussed in the Steps Between Gears section, with the conclusion being that gaps that exceed 15% between adjacent gears are quite noticeable and it’s best when these are minimized. Therefore, the number of such gaps and the size of the largest gap are important characteristics of a cassette and when cassettes with a certain gear range is available from multiple brands, only the version that has better spacing in terms of the fewest gaps of more than 15% is included.

Brands considered were Campagnolo, IRD, Miche, Shimano, SRAM, and SunRace. In my experience, shifting between cogs is smoothest on Shimano cassettes, slightly inferior with SRAM and Campagnolo, and generally poorer on cassettes from other brands, which is why I’ve ignored other brands when there is an option from one of the 3 main brands.

Cassettes with 9-tooth cogs were not considered because they are too inefficient and not durable (which is why there are not offered by any of the 3 main brands). Hope cassettes were not considered because they do not fit on wheels from other brands.

The largest cog size that a rear derailleur can handle is an important consideration when choosing a cassette, so that is covered in the Rear Derailleur Compatibility section.

There are often multiple versions of the same cassette offered by a manufacturer at different price levels. This is ignored here because generally the cog sizes and shifting ramps are identical across all versions, so shifting should be very similar. The differences are whether the larger cogs are mounted to lightweight carriers or are heavier individual cogs, the finishing of the material, and sometimes the material of the cogs and/or lockring.

Which type of freehub body is needed for each cassette is noted and this is possible to change on many wheels. A lot of cassettes work on Shimano/SRAM 11-speed freehub bodies (denoted Sh/SR-11). Shimano 11-speed cassettes with at least 34 teeth fit on the slightly narrower 8/9/10-speed Shimano freehub body (found on older wheels and MTB wheels) and can also be used on 11-speed freehubs by using a spacer, and so are denoted Sh/SR-10+11. ‘Shimano MS’ refers to Shimano’s ‘MicroSpline’ 12-speed MTB freehub body, which is currently only available for certain wheels. Campagnolo bodies have been the same for everything from 9- to 12-speed road cassettes. SRAM cassettes with a 10-tooth cog require the SRAM XD body for MTB cassetttes and the XDR version for 12-speed road cassettes (which is slightly longer).

11-Speed Cassettes

Spacing between cogs is the same for all 11-speed systems, so all cassettes should work with 11-speed systems from other brands.

Tooth Range   % Range   Brand Freehub Body   Steps > 15%   Largest Step  
13-34 262% Miche Sh/SR-11 0 13.3%
11-29 264% Campagnolo Campagnolo 0 13.3%
12-32 267% IRD / Miche Sh/SR-11 0 14.3%
11-30 273% Shimano Sh/SR-11 0 14.3%
12-34 283% Miche Sh/SR-11 0 14.3%
11-32 291% Shimano Sh/SR-11 0 14.3%
12-36 300% IRD Sh/SR-11 1 15.4%
11-34 309% Shimano Sh/SR-10+11 2 18.2%
11-36 327% SRAM Sh/SR-11 2 15.8%
11-40 354% Shimano Sh/SR-10+11 2 18.2%
11-42 382% Shimano Sh/SR-10+11 4 18.2%
10-42 420% SRAM SRAM XD 5 20.0%

Note that Miche sells custom cassettes where cogs can be chosen individually, starting with an 11, 12, or 13 tooth cog and going up to 30, 32, or 34 teeth. Range and spacing can therefore be chosen more freely, but shifting is poorer because the ‘timing’ of the shift ramps on adjacent cogs cannot be optimized as is done with complete, stock cassettes. IRD cassettes are designed in a similar way, but sold only as complete cassettes.

12-Speed Cassettes

Whereas 11-speed cassettes from different manufacturers have the same spacing between cogs and so are cross-compatible, I’m not sure whether this is true for all 12-speed cassettes. Please comment below if you know whether the spacing is the same for Shimano and SRAM MTB 12-speed cassettes (I believe so, but I’m not sure)? Also, how about SRAM and Campagnolo road 12-speed (I have no idea here)?

For 12-speed cassettes, it is notable that there is a void between road cassettes that have a maximum range of 330% and MTB cassettes that have a minimum range of 450%. Hopefully someone will fill this gap in the market soon.

Due to odd choices of cog sizes, the only 12-speed cassette that outperforms the equivalent 11-speed cassette in terms of spacing is the Campagnolo 11-29. This is perplexing and I again hope that new models will be released soon that address this. Shimano is expected to announce a 12-speed road groupset during 2020 that should be available by the end of the year and may include some better cassette options.

Tooth Range   % Range   Brand Freehub Body   Steps > 15%   Largest Step  
11-29 264% Campagnolo Campagnolo 0 13.0%
10-28 280% SRAM SRAM XDR 1 16.7%
11-32 291% Campagnolo Campagnolo 1 15.8%
10-33 330% SRAM SRAM XDR 2 17.9%
10-45 450% Shimano Shimano MS 4 20.0%
11-50 455% SRAM Sh/SR-10+11 5 19.0%
10-50 500% SRAM SRAM XD 6 20.0%
10-51 510% Shimano Shimano MS 7 20.0%

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