Let's try another analogy. Imagine a stopped bicycle with the pedals horizontal to the ground. Now imagine putting the brakes on and standing on the pedal in an attempt to move the bike forward. The amount of force you apply on the pedal is called torque. The heavier you are, the more torque you can apply on that pedal.
Now for those of you who think torque gets you up the mountain. I'd like to challenge you to get a 250 pound athlete with more torque to compete against a 150 pound athlete with less torque on a similar bike. The lighter athlete will have two advantages, 1) they are lighter and will require less work to get up the mountain and 2) they can turn the pedals faster than the heavier athlete because their legs also weigh less.