This article is part of a series featuring bike designer Mike Salvatore and mechanic Ben Fietz of Chicago’s Heritage Bicycles. Consider using these tips during Bike to Work Week, and check Groupon to discover cycling deals in your city. You’re cycling down the road and the gears begin to stick. Maybe you hear a crunching or scraping sound. Unless you’ve stumbled into a very unlikely patch of quicksand, you’re probably just in need of a little chain lube. According to mechanic Ben Fietz of Heritage Bicycles, maintaining your drivetrain is essential to biking safely and comfortably. “If you’re riding a fixed-gear bike or a bike with a coaster brake, your chain is integral to the whole braking system,” he said. “With a regular bike, if you break a chain, you want to get to the bottom of what caused it instead of just throwing [one] back on.” Step 1: Choose the right lubricant. You can find both wax- and oil-based lubricants, but choosing which to use depends on three factors: how much you ride, where you ride, and what kind of weather you ride in. “If you’re a hardcore commuter, you’re gonna ride in rain or shine,” Fietz said. In that case, “you’re gonna need a pretty burly lube,” something that keeps the chain clean and clear of grime, especially on Chicago’s dirty urban streets. Wax-based lube is ideal for warding off grime, but the slicker oil-based varieties have their own merits, too. For Chicago’s climate, Fietz recommends Chain-L—it’s what his shop uses, and it works in a range of conditions. “It’s really smooth and keeps everything running, but it’s also really thick and holds up in tough weather.” Step 2: Lube the chain. If you don’t have the benefit of a kickstand, just flip your bike upside-down so the saddle and handlebars are resting on the ground. Then, hold a fresh rag dabbed with chain cleaner around the exposed chain (if you don’t have any cleaner, lube will work just fine). Rotate the pedals backward to run the chain through the rag, removing any grime or crust. Next, take a small brush and clean the cassette (the cogset on the hub of your rear wheel that allows the chain to shift gears). Finally, drip the lube over the chain where it meets the cassette—all while running the chain backward for a few rotations to ensure even coverage. How often should you do it? There’s no real rule of thumb, said Fietz, but “too much lube is better than not enough.” Casual riders can go for a few weeks, but a more avid cyclist should probably reapply lube almost every long trip. When in doubt, just touch your chain. “If it feels dry, it’s time to reapply.” Check out our step-by-step demonstration below: Photos: Andrew Nawrocki, Groupon.