The Tern Chain Guide Pulley Wheel (SKU: BKTNP365) is a replacement chain idler/pulley wheel designed for Tern cargo and compact e-bikes with chain derailleurs. It helps maintain optimal chain tension, prevents the chain from scraping against the bike's frame, and ensures crisp shifting.

• Compatibility: Fully compatible with the Tern GSD (Gen 1 & Gen 2), Tern HSD, Tern Quick Haul, and Tern Short Haul. 
• Design Update: The original smooth rubber pulley wheels on older models were prone to wearing down and grooving quickly. Tern has since introduced an updated, more robust sprocket-type jockey wheel design (similar to a derailleur cog) for significantly improved chain engagement and durability under heavy cargo loads.
• Replacement Interval: This is considered a routine service item. Depending on riding conditions and chain cleanliness, it generally needs to be replaced roughly every 3,200 km (2,000 miles)