| Specification | Value |
|---|---|
| Production Years | 2018–2021 |
| Engine Type | Milwaukee-Eight 107 (1746cc) |
| Oil Type & Capacity | 20W50 (4.3 L) |
| Tire Size (Front) | 130/90B16 67H |
| Tire Size (Rear) | 150/80B16 77H |
| Spark Plugs | H-D 6R10 |
| Battery Code | 66000207 (YTX20HL) |
Engineering Highlight: The 2018 introduction of the FLHC Heritage Softail Classic represented a paradigm shift in Harley-Davidson’s chassis design. It was the first Heritage model to utilize the redesigned Softail frame, which is 65% stiffer than its predecessor, effectively merging the rigid aesthetic of a classic cruiser with the high-performance handling characteristics of the discontinued Dyna line.
Technical Overview: The Milwaukee-Eight 107
The heart of the FLHC is the Milwaukee-Eight 107 engine. Unlike previous Twin Cam iterations, this powerplant features a four-valve cylinder head design and a single counter-balancer that cancels 75% of primary vibration at idle. This engineering choice preserves the ‘soul’ of the V-twin while significantly reducing rider fatigue during long-distance touring. The 107 cubic inch displacement provides a broad torque curve, peaking early to facilitate effortless overtaking even when fully loaded with gear.
Maintenance Guide & Fluid Specifications
To maintain peak performance and longevity of the M8 engine, strict adherence to fluid intervals is required. The engine utilizes 4.3 Liters of 20W50 synthetic or high-quality mineral oil. At MotoSpecsLab, we recommend checking the oil level when the engine is at operating temperature to ensure accuracy.
Tires and Chassis
The Heritage Softail Classic relies on a specific tire configuration to maintain its iconic silhouette and handling balance. It uses a 130/90B16 67H on the front and a 150/80B16 77H on the rear. For optimal safety and fuel economy, tire pressures must be maintained at 2.5 bar (36 psi) for the front and 2.8 bar (40 psi) for the rear.
Electrical System
The FLHC is equipped with a high-output charging system to support its LED lighting and optional accessories. The OEM battery replacement is the 66000207 (YTX20HL). When replacing spark plugs, the H-D 6R10 is the factory-specified component, gapped to ensure efficient combustion within the high-compression M8 cylinders.
MotoSpecsLab Editorial Review
The Heritage Softail Classic (107) is perhaps the most versatile motorcycle in the Softail lineup. By shedding nearly 33 pounds compared to the previous generation and gaining the M8 engine’s thermal efficiency, it transitioned from a ‘boulevard cruiser’ to a legitimate cross-country tourer. While the 114 CUI variant offers more raw power, the 107 provides a smoother, more balanced delivery that many veteran riders prefer for its reliability and heat management.