The Problem Solvers Chain Tensioner is a handy device when you're building a singlespeed bike and need to remove slack in the chain and keep it running smoothly. It's made of light and durable CNC-machined 6061 aluminum with steel hardware and has efficient, long-lasting nylon pulleys. It simply screws onto your frame's derailleur hanger. It even lets you adjust your chainline, too.
WARNING: This product can expose you to chemicals, including lead, known to the state of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.