Understanding gear ratios is fundamental for cyclists looking to maximize their efficiency and enjoyment on any terrain. Whether you’re tackling steep climbs, cruising on flat roads, or navigating technical trails, the right gear ratio can make all the difference. A Gear Ratio Calculator Bike, like the one pioneered by the renowned cycling expert Sheldon Brown, is an invaluable tool for cyclists of all levels. This article delves into the world of bike gear ratios and how you can use a calculator to optimize your cycling experience.
Sheldon Brown’s Derailer Gear/Internal-Gear Calculator is a comprehensive resource designed to help cyclists understand and calculate their bike’s gear ratios. This tool is especially useful for those using derailleur gears or internal gear hubs. You need to input information for at least one chainring and one sprocket, or you can select from a list of stock cassettes or internal hubs. The calculator includes a vast database of internal gear hubs, dating back to early models from 1902 Sturmey-Archer, and many internal-gear hubs and cassettes, though some are no longer in production.
Once you input your data and click “calculate,” the tool generates two output pages. One is a full-size page with detailed information, and the other is a smaller, printer-friendly version you can easily attach to your bike’s handlebar stem for quick reference during your rides. This handy feature allows you to have your gear ratio information readily available whenever you need it.
The gear ratio calculator bike tool is incredibly comprehensive. It features an extensive selection of internal-gear hubs, only missing a few very recent models with unpublished gear ratios and some extremely rare antique models. The cassette selection is regularly updated, including models from Shimano, SRAM, SunRace, and recent Campagnolo offerings as of February 2018. For components not listed, or for custom cassette setups, you can manually enter the number of teeth for each sprocket under the “custom sprockets” option. Sheldon Brown’s cassette page provides further details on cassette sprocket tooth counts.
For cyclists using a Schlumpf Drive in combination with an internal-gear rear hub, the calculator accommodates this setup. You should enter the actual tooth count of your front chainring as the first chainring value. For the second chainring, input the tooth count multiplied by the Schlumpf Drive ratio. The ratios are 0.40 for the Mountain Drive, 1.65 for the Speed Drive, and 2.50 for the High Speed Drive.
While most modern internal gear hubs aren’t designed for rear sprocket clusters, there are exceptions. The SRAM/Sachs 3 x 7, 3 x 8, 3 x 9, 3 x 10 series and the Sturmey-Archer CS-RF3 and CS-RK3 are designed to work with rear sprocket clusters. The Sturmey-Archer-Brompton BWR hub is another example, accommodating two sprockets. These options, along with others in the list, cater to tinkerers and those exploring hybrid setups, as discussed further on Sheldon Brown’s page about internal gears.
For those who prefer a more traditional approach, Sheldon Brown even jokingly suggests: You can use your slide rule instead!
Understanding gain ratios, gear inches, and meters development are all essential aspects of bike gear ratios. Sheldon Brown’s website provides resources to learn more about these concepts and percentages in gear ratios.
The Sheldon Brown gear ratio calculator bike tool relies on JavaScript to function. If you encounter issues, ensure your browser has JavaScript enabled and that any pop-up blockers are disabled, as the results open in a new window. For multiple calculations, it’s recommended to close each results window after use to avoid them being hidden behind each other.
For further exploration and more advanced calculations, consider these resources:
- Mike Sherman’s gear calculator: Mike Sherman’s gear calculator provides RPM range vs. speed data.
- HPV Drivetrain Analyzer: HPV Drivetrain Analyzer (via the Internet Archive) offers a more elaborate calculator, including speed and cadence data. Note: the calculator itself may not be functional on the archived page.
- “Rabbit, A Singlespeed and Fixed-gear Calculator”: Rabbit Calculator by Tom Kunicki is tailored for fixed-gear and singlespeed riders.
- “Drive ratios of bicycle hub gears” by John Allen: John Allen’s Gear Ratio Page provides precise, fractional ratios derived from gear tooth counts.
Explore these resources and the Sheldon Brown gear ratio calculator bike to gain a deeper understanding of your bike’s gearing and optimize your cycling performance.
Original content and tool by Sheldon Brown. This content is for informational purposes and based on the original resource.
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