Selecting the right road bike involves many factors, and for those who love tackling hills, understanding gear ratios is crucial. While the amount of climbing might seem important, it’s actually the steepness of the inclines that truly dictates your gearing needs. Combined with your power-to-weight ratio, the gradient will determine your climbing speed and, consequently, the ideal gear ratio for your road bike. For long rides, especially those in mountainous regions, you’ll likely want to maintain an effort level well below your Functional Threshold Power (FTP).
To determine the appropriate chainring and cassette combination, focus on the sections of your ride where you anticipate the slowest speeds, typically the longest and steepest climbs. Utilize online tools to estimate your speed on these climbs. By inputting your weight, your bike’s weight (including essentials like water, spares, and nutrition), your target power output, bike type, and the gradient, these tools can predict your climbing speed.
Once you have an estimated speed, you can use a gear ratio calculator. Input your tire diameter, chainring sizes, and preferred cadence to explore different cassette options. Experiment with various combinations to find a setup that provides comfortable pedaling even on the steepest sections. It’s always wise to have a spare gear available, preventing you from being forced to ride at an excessively low cadence in your smallest gear for extended periods. When deciding between cassettes, opt for the one with lower gears, meaning larger sprockets. Cyclists rarely regret having gears that are too low, especially after completing challenging mountain rides. It’s far more common to wish for easier gears on tough climbs than to complain about not having enough top-end speed on an ascent.
Even cyclists with good fitness and average weight often choose a 1:1 or lower gear ratio for demanding Alpine climbs. This ensures they have sufficient gearing to conquer steep gradients efficiently and comfortably. Understanding and carefully selecting your gear ratio is a key aspect of choosing the Best Road Bike for your riding style and terrain, especially if climbing is a priority.
