crank size vs. 1:1 gear on a b*ke

So, in my new obsession with hill climbing, I was reading about bikers and their gear choices on the mountain climb races, such as Mt. Washington, where there’s 8 or so miles at an average 12% grade.

Bikers choose a gear said be to less than 1:1. That is, their front chain ring is smaller than their rear chain ring, and for each pedal, they travel less than one wheel’s revolution.

Unicyclists always have 1:1 ratios (except for those crazy geared jobs), and we vary crank length to make it easier to pedal, right? Has anyone quatified crank length vs. bicyclists’ gear? That is, how much easier is it to pedal with longer cranks, like 125mm vs. 150mm vs. 175 mm.?


Don’t forget to consider the bicyclists crank size. It has the same effect.

Oh. Yeah, I guess it does.

Just compare torque at the ground. The two factors for unis are wheel diameter and crank length. For bikes it is both of these and gear.