It has happened to nearly all of us, you are riding your bike fast somewhere and suddenly your chain falls off. What comes next is usually either a scary crash, or your hands covered in grease trying to get your chain back on. Chain guides and tensioners are designed to keep your chain properly connected to your bike so you can enjoy your ride without fear of another chain related crash.

Chain guides: are usually necessary on any bike that has a single chainring in the front and gears in the back. The invention of narrow-wide chainrings has allowed bikes with 1x drivetrains to function without a chain guide, but many riders don’t have full confidence in the narrow-wide tech and choose to run a chain guide anyway. Bikes with front derailleurs and multiple chainrings do not need a chain guide because the derailleur keeps the chain on the rings. Chain guides with a lower pulley also exist to help keep the chain away from rocks and debris on the trail. This kind of chain guide is commonly found on downhill and freeride bikes. A lower pulley guide can also be used to tension a chain on a single speed setup buy rotating the guide around the ISCG tabs until proper chain tension is achieved.

Chain Tensioner: The other way to tension a single speed chain is with a derailleur style chain tensioner. These tensioners attach to a frame’s derailleur hanger and use a spring and pulley to tension the chain. If a bike has horizontal dropouts it does not need a tensioner to be ran as a single speed. Sliding the wheel within the dropout can tension the chain. If the chain doesn’t tighten within the dropout spacing, you may need to cut your chain down or use a half-link chain instead.

If you have any questions about chain guides and tensioners, hop on a call or a chat with one of our expert Gear Advisors today at 888-880-3811. They are always happy to help you with any questions you may have.