TERN GSD S10 Slipping Mid Drive

KMC e10 E-Bike Rated 10-Speed Chain

Mid-drive motors apply extreme tension to the chain, causing accelerated wear on the internal pins and rollers. Once the chain pitch exceeds the tolerances of the gear teeth, it will skip over the cassette cogs under load, which the user perceives as slipping. This e-bike specific chain is reinforced to handle the higher torque loads of the GSD's Bosch motor.

SKU: KMC-e10-S

Shimano Deore 10-Speed Cassette (11-36T)

The cassette teeth develop a 'shark-fin' profile as they wear down under the high torque of a cargo e-bike. This wear prevents the chain from fully engaging with the teeth, particularly in the smaller cogs used for higher speeds. Replacing the cassette in conjunction with the chain is required to restore proper mechanical indexing and prevent immediate slippage.

Tern GSD Idler Pulley/Chain Roller

The GSD utilizes a proprietary idler roller to manage the long chain line and ensure sufficient chain wrap around the mid-drive motor sprocket. If the roller's bearing seizes or its teeth wear down, the chain can lose tension and skip at the front drive sprocket, especially when navigating bumps or hauling heavy loads.