From Off-Season to Adventure: How We Built the Protocol RCG-4 Gravel Tire

The Protocol RCG-4 is our all-weather gravel tire for training and adventure when dry, dusty roads give way to softer, muddier, sloppier tracks. We designed the Protocol gravel lineup around these seasonal changes in riding surfaces, with the RCG-4 built for the demanding end of that spectrum. 

Gravel isn't a monolith. From Category 1 gravel roads, which feature smooth, hard-packed dirt, to Category 3 roads that consist of rough, poorly maintained surfaces with ruts and rocks, gravel consists of a wide range, and no single tire is meant to perform across it all. There will always be trade-offs between rolling resistance, traction, and puncture protection.  

To minimize those trade-offs, we designed the Protocol lineup around a common foundation of supple casings and a proprietary Pulsar rubber compound, while tailoring each model's tread architecture to different terrain. Within this ecosystem, the fast-rolling RCG-1 rules the hardpack, the versatile RCG-3 handles general race days, and the RCG-4 is meant for the extremes. 

For riders chasing year-round exploration and off-season training, the RCG-4 serves as our all-weather adventure tire. When dry roads degrade into wet, leaf-covered slop or technical backcountry routes get demanding, typical gravel tires designed for speed rather than grip can quickly lose their composure.  

The RCG-4 combats this with our most aggressive, widely spaced lug pattern, engineered to maintain grip and shed mud. Unlike tightly clustered knobs that can trap debris and turn gravel tires into slicks, the RCG-4’s open-channel design sheds mud with each rotation. This self-cleaning action keeps the tall tread knobs biting into the surface, giving you consistent engagement through loose rock, wet roots, and slippery mud. 

Beyond sloppy weather riding, the RCG-4 is the choice for off-season base training, where reliability and comfort matter more than speed. Available in three high-volume sizes (700 x 45mm, 50mm, and 55mm), it allows you to safely drop tire pressures to absorb harsh winter surfaces and maximize your contact patch.

But don’t take our word for it. Numerous independent reviewers are all saying the same thing. For example, the team at Bicycle Station recently published a video review claiming the Protocol RCG-4 mounted on shallow, wide internal carbon rims highlight its exceptional off-road performance. While running lower pressures ranging from 18 psi in the front and 19 psi in the rear, they stated that the tire excels on rough descents and brake bumps, offering superior puncture resistance, a forgiving contact patch, and heightened dexterity that allows for easily switching lines and maintaining control through technical turns.

Built with a robust, bead-to-bead, puncture-resistant casing layer, it shrugs off hidden rocks, sharp gravel, and wet debris that typically hinder cold-weather training rides. By trading a few watts of rolling resistance for durability and predictable cornering, the RCG-4 helps you focus on the ride rather than stressing about mid-ride flat repairs in freezing conditions. 

Additionally, they pointed out that the RCG-4 functions like as a mountain bike tire adapted for gravel platforms, making it an ideal choice for aggressive adventure touring, loose terrain, and sloppy conditions. 

Ultimately, the RCG-4 reminds you that your riding season doesn't have to end when the weather turns foul. While summer events call for the speed and efficiency of an RCG-1 or RCG-3, keeping an RCG-4 in your rotation turns shoulder-season slop from a hindrance into an opportunity. 

Thanks to our friends at Slug Bicycles for these excellent images!