The situation: You’re pedaling up a climb when your foot jars to a stop on the downstroke. The chain’s dropped and you’d prefer to eschew the humiliating and greasy task of stopping to wrestle it back on. What do you do?
The fix: Stop pedaling and look down. If the chain is caught between your bike and inner chainring, shift up into the bigger ring while pedaling very gently. If the chain’s heading into your pedal, shift down. In most cases, you'll be able to set the chain without dismounting your bike.
If all else fails, hop off the bike and push the rear derailleur toward the handlebars. That’ll give you enough slack to get the chain back into place. But before you hop back on, turn the cranks to get back into the right gear.
In the future, ease up on the pedals when shifting between chainrings to avoid damaging your components, Kreidl says. If the problem persists or you’re trying to take your cycling to the next level, invest in a chain catcher.