Gear Calculator Chart

HISTORY (skip down to THIS CHART if you aren’t curious)

In the ‘70s all riders knew about gear charts, because they were a regular feature in magazine articles and bicycle-seller catalogs. They’ve since faded away a lot, as part of the general fear of scaring away potential bicycle riders with numbers or math. Nevertheless, gear charts are the simplest way, and maybe the only way, of comparing different chainring and cog combinations to see which one is harder or easier.

The traditional American-and-British gear-inch chart was popular in non-metric countries (England, the U.S.), and the numbers in the grid that corresponded to the various gear combinations were, sit down/hold onto your hat, the equivalent wheel diameters (and gearing) of an 1870s penny-farthing (high-wheeler) front wheel. This made sense during the transition from high-wheeler to “safety bicycle” with front and rear gears and same-sized wheels. But with high-wheelers about 150 years in the past, the high-wheeler frame of reference is confusing and weird.

The metric countries had a more normal way. On their gear charts, the numbers were the distances traveled for every 360-degree turn of the crank, as calculated in meters. It’s a more logical way to do it, but runs into a cultural snag if you grew up staring at American football fields marked in yards. So in the chart here, we’ve taking the logic of the metric way and converted the numbers from meters to yards, and it’s based on a 700C x 40mm tire. If your tire is bigger, you’ll go farther per revolution; smaller, less far.

THIS CHART:All of the ratios that give you the same distance are effectively the same gear, all you need to know is that the numbers are the numbers of yards per complete revolution, and the bigger the number, the harder the gear. 

 For flat to rolling riding with moderate fitness and reasonable strong legs, 5.9 is not bad at all. If you’re super strong and want to go faster on flattish roads get a gear in the low-to-mid 7s. 

 Practically, the lowest gear you can get on the Roaduno with the stock 38x26 front rings and a 22t rear cog (the biggest single-speed freewheel we’re able to find or care to stock) is 2.7. You may still grunt up the steepest hills with that, but that’s the deal—the limitation and the fun— with bikes like this. If you keep the 26t small ring and add a 22t cog, you’re up to 2.9 yards. Experiment with your multi-geared bike to helps you zero in on the gears you want for your 1-, 2-, or 3-speeder.

Traditional Gear Inch Chart - assumes a 27" diameter wheel: