2015 Harley-Davidson® FLHTK - Ultra Limited

The 2015 Harley-Davidson® FLHTK Ultra Limited represents the high-water mark of the "Project RUSHMORE" era. When Harley-Davidson launched Project RUSHMORE in 2014, it wasn't just a marketing slogan; it was a fundamental shift in how the Motor Company designed motorcycles. For the first time, Harley-Davidson leaned heavily on thousands of hours of rider feedback to overhaul their touring line. The 2015 Ultra Limited is the beneficiary of that exhaustive research, offering a machine that retains the soul of a classic American tourer while embracing the technological necessities of the 21st century.

The Heart of the Machine: Twin-Cooled™ High Output Twin Cam 103™
At the center of the 2015 FLHTK is an engine that solved a century-old problem for Harley-Davidson: heat. The Twin-Cooled™ High Output Twin Cam 103™ engine was a revolutionary step forward. While the engine looks like a traditional air-cooled V-Twin at a glance, it features a "split-cooled" system. Liquid coolant is circulated through the cylinder heads specifically around the exhaust valves—the hottest part of the engine—before being routed to two small radiators hidden inside the fairing lowers.

This engineering choice serves two purposes. First, it allows for a higher compression ratio (10.1:1), which results in more power and torque—specifically 105.5 lb-ft at 3,750 RPM. Second, it drastically improves rider and passenger comfort. Anyone who has sat on a large-displacement air-cooled bike in mid-August traffic knows the "barbecue" effect. The Twin-Cooled system mitigates this significantly, ensuring the engine stays at peak operating temperature even under the heavy load of a fully packed bike on a mountain pass.

The Project RUSHMORE Enhancements: Control and Confidence
The 2015 Ultra Limited was built under the philosophy that a rider should never feel like they are fighting the motorcycle. This led to the development of the Reflex™ Linked Brakes with ABS. This is not a simple linked system; it is an electronic "brain" that monitors vehicle speed and brake pressure. If you apply the rear brake at speeds above 20–25 mph, the system calculates exactly how much front brake to apply to keep the chassis level and stable. This is particularly vital on an 896-pound machine where weight transfer during braking is a major factor in safety.

Furthermore, the 2015 model features a stiffer 49mm front fork. This increased diameter reduces "fork flex" during aggressive cornering or heavy braking, giving the rider a much more connected and precise feel of the road. When you combine this with the Day maker™ LED Headlight and Fog Lamps, the 2015 Ultra Limited becomes a machine that can be ridden with total confidence well after the sun goes down. The Day maker system doesn't just "glow"; it carves a path through the darkness with a punchy, white light that improves peripheral visibility by 45% over standard halogen bulbs.

Aerodynamics: The Science of the "Split stream"
One of the most praised features of the 2015 Ultra Limited is the redesigned Batwing Fairing with the Split stream Vent. Historically, the Batwing fairing was known for "head buffeting"—that annoying vibration of the helmet caused by the vacuum created behind the windshield.

Harley-Davidson’s engineers spent hundreds of hours in the wind tunnel to create the Split stream vent. By opening the vent located just below the windshield, air pressure is equalized between the front and the back of the fairing. This eliminates the vacuum effect and allows air to flow smoothly over the rider's head. It is a simple, mechanical solution that transformed the Ultra Limited from a bike that was "comfortable" into a bike that could be ridden for 800 miles in a single day without the rider feeling physically exhausted.

Infotainment: The Boom!™ Box 6.5GT
In 2015, the Boom!™ Box 6.5GT was the gold standard for motorcycle infotainment. It features a 6.5-inch full-color touchscreen that is designed specifically for use with gloves. But it goes beyond just a screen; it featu

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