I don’t know about you, but knowing when to shift gears on a bike eludes me. I know what I should do when going uphill and downhill, not so sure about the in-between. By now you’ve decided to start biking and you’re doing well, but you’re ready to know about be much more efficient on your bike using its gears. This article from Bicycling Magazine breaks it down very simply.
The Situation: A long, gradual road climb
The Shift: This is usually the easiest shifting situation, after flat terrain. At the base of the climb, you should be in your comfort-zone gear–it varies from rider to rider, but for most of us it’s in the 90-revolutions-per-minute range. When your cadence starts to slip, ease the pressure off the pedals slightly and shift into an easier gear. Remember, shifting in the front means a big resistance change; rear shifts are for fine-tuning your cadence. If you need to stand, shift up a cog or two in the rear; the slightly harder gear will allow a smooth transition. Shift between these sitting and standing gears as you make your way up the climb.
The Situation: A moderately steep, twisty, rocky descent on your mountain bike; the trail ends smoothly before transitioning to a long climb
The Shift: This is a heavy shifting situation. On the way down the slope, you’ll want to shift around to stay on the harder-geared side of your comfort zone, so you can power out of corners and over most obstacles. (But don’t stray too far—if you get hung up on something, you’ll want to be in a gear you can manage at a slower pace.) During the transition, soft pedal and shift to the lower gear you’ll need to start the climb—you want to be in your comfort zone at the beginning of the uphill.
The Situation: A group road ride that’s heading into a sprint-finish area
The Shift: The biggest mistake most of us make in just-for-fun sprints is telegraphing our move–we suddenly (and noisily) shift into much higher gears, alerting everyone to our intentions. Surreptitious presprint shifting is partially done in advance (with the front chainring) and partially on the fly–you need to be in only a slightly harder gear to start, as upshifts in the rear can be managed after you jump. Move up one gear at a time, spinning out each gear (meaning faster than your comfort zone) before shifting again.
The Situation: A rock-strewn, technical climb on your mountain bike
The Shift: Use too low a gear on a loose, technical climb and you’ll spin the rear wheel, lose momentum, and come to a halt. To avoid that, climb in a slightly higher-than-comfort-level gear, which helps the rear tire grip the terrain and gives you leeway for the short power bursts needed to ascend larger rocks or log step-ups. Don’t expect to reach the top of the climb without feeling your muscles burn—in a good way, of course.
I’m just keeping it new.