Which component may be a double roller style for increased durability?

• A. Camshaft
• B. Timing Chain
• C. Lifter
• D. Adjustable Cam Gear

Answer: (B)

A double roller design is a feature used on timing chains to increase strength and reduce stretch, which helps keep valve timing precise under higher loads or with more wear. The timing chain is the link between the crankshaft and the camshaft(s); when it’s built as a duplex or double-row chain, it resists elongation better and runs more smoothly, enhancing durability and reliability over time. That improvement in wear resistance and timing stability is why the double roller style is associated with the timing chain.

The camshaft itself is driven by a chain or gear, but the double roller description specifically refers to the chain construction, not to the cam shaft. A lifter is a follower that rides on the cam lobes and doesn’t involve a double roller chain. An adjustable cam gear relates to timing adjustment, not the chain’s structural design.