Gravel climbing gears: calculate how far each pedal turn takes you
The easiest gear on a bike is the one that moves it the least distance per pedal turn. Count teeth first: the smallest front ring divided by the largest rear sprocket. Then include wheel rollout if the two bikes use different tire packages. The number of speeds printed on the shifter is not the answer.
From teeth to distance
Multiply gear ratio by the wheel’s actual rollout to obtain distance per crank revolution. Using an illustrative 2.20 m rollout, 42/42 gives 2.20 m and 30/34 gives about 1.94 m. These are calculations, not claimed measurements for a GRARO build or a particular tire. Wheel rollout can be measured by an appropriate loaded roll-out method or obtained from reliable setup-specific data.
Make the difference tangible
At an illustrative 60 rpm, multiply distance per turn by 60 turns per minute and 60 minutes per hour, then divide metres by 1,000. The result is about 7.92 km/h for 42/42 and 6.99 km/h for 30/34 with that same 2.20 m rollout. The lower gear lets you pedal at the same cadence at a lower speed. It does not guarantee you can climb a particular gradient.
That cadence is only an arithmetic example, not a training target. Rider capability, load, surface and gradient still matter. Compare with a gear you already use successfully, rather than adopting another rider’s lowest ratio as your requirement.
Give the builder an actual target
For an ICAN GRARO order, specify your desired lowest ratio or distance per turn and intended tires. Ask for the full approved drivetrain that achieves it. A larger cassette requires the appropriate derailleur, freehub, chain and frame compatibility; fitting more teeth is not the whole change.
If choosing between complete systems, use the 1×/2× worked comparison next. Keep your climbing target on the page while comparing top gears. A fast downhill gear is pleasant; the uphill gear is the one you cannot borrow from gravity.
Sources
Source review began . Research methodology.