CX/Gravel Tire Test: Silca Protocol RCG-1 45

Silca is an American (with Italian heritage) cycling parts and accessories brand known for its high-quality products. They recently introduced a lineup of gravel bike tires, and that's where we usually get skeptical. Tires are completely different from most other cycling parts, as you're competing with companies that have put 100+ years of research into compounds and tire technology, and they usually keep the good stuff to themselves.

For a brand like Silca, that means competing in the tire market takes a serious investment of time and money, as well as building relationships with manufacturers, suppliers, and specialists who know how to build the perfect tire. To put a long story short, we can confirm Silca went the extra mile as our test results, of at least the Protocol RCG-1, show it can compete with the best tires we've tested to date.

There was quite a bit of controversy about these new Silca tires, and they've quickly become the most requested and voted-for tires on our Pro Members tire voting system. It took some time to find these for sale in Europe, but we've worked hard to get the results out as quickly as possible. We want to thank all our Pro Members for their support, voting requests, and votes over the past 5+ years!

The Protocol RCG-1 is Silca's fastest gravel bike tire, and it's the right tire to start our testing of Silca's new tires. The RC (Race Casing) in RCG-1 means it has a 120 TPI race casing, with a specified weight of just 460 grams, making it one of the lightest 45 mm gravel bike tires on the market. Our sample even came in at just 442 grams, while most competitors come in a bit over the specified weight. Even though Silca claims "GhostShield" protection, it has no additional breaker layers, which we find a bit misleading.

While the compound is the most important ingredient in a tire, we can't find much information about Silca's Pulsar compound beyond that it's a "high performance rubber and silica race compound engineered to hold rolling efficiency, grip, and durability in balance rather than trading one away for another". Testing the compound is the real strength of our tests, as it will quickly show if this part of the tire isn't up to par.

We've compared the 45 mm Silca RCG-1 to its main competitors, the Schwalbe G-One RS, Hutchinson Caracal Race, Tufo Gravel Thundero, Continental Terra Speed and Terra Competition, and some other gravel bike tires with similar properties.

Manufacturer Specifications

Manufacturer Specs
Brand	Silca
Model	Protocol RCG-1
Year	2026
Supplied By	Bought in store
New or Used	New
Mileage	0 km
Price Range	Very High
Buy At
Manufacturer part number	-
EAN	810093163281
TPI	120
Compound	Pulsar Compound
Bead	Folding
ETRTO	45-622
Specified Weight	460 grams
Max Air Pressure (psi)	50
Made In	Pro Data
Available Sizes	45-622 (700x45c) 50-622 (700x50c) 55-622 (700x55c)

Silca Protocol RCG-1 45 Test Results

Size, Weight, and Thickness Measurements

Size, Weight, and Thickness Measurements
Specified Weight	460 grams
Measured Weight	442 grams
Measured Width Casing	43 mm (un-round)
Measured Width Tread	45 mm
Measured Height	Pro Data
Tire Circumference	Pro Data
Measured Knob Height Center	0.7 mm
Measured Knob Height Edge	2.7 mm
Measured Total Thickness Center (excluding knobs)	1.80 mm
Measured Total Thickness Sidewall	Pro Data
All size measurements are taken at low air pressure on a 17.8 mm inner width rim.

Rolling Resistance Test Results

Rolling Resistance Test Results
Inner Tube	None (30 ml sealant)
Measured Width	43 mm
Rolling Resistance Real tire width in mm: 30-32 = 66 psi/4.6 bar 33-35 = 60 psi/4.1 bar 36-38 = 54 psi/3.7 bar 39-42 = 50 psi/3.4 bar 43-46 = 46 psi/3.2 bar 47-50 = 42 psi/2.9 barHigh Air Pressure (46 psi / 3.2 bar)	Pro Data
Rolling Resistance Real tire width in mm: 30-32 = 55 psi/3.8 bar 33-35 = 50 psi/3.4 bar 36-38 = 45 psi/3.1 bar 39-42 = 42 psi/2.9 bar 43-46 = 38 psi/2.6 bar 47-50 = 35 psi/2.4 barMedium Air Pressure (38 psi / 2.6 bar)	Pro Data
Rolling Resistance Real tire width in mm: 30-32 = 44 psi/3.0 bar 33-35 = 40 psi/2.8 bar 36-38 = 36 psi/2.6 bar 39-42 = 33 psi/2.3 bar 43-46 = 31 psi/2.1 bar 47-50 = 28 psi/1.9 barLow Air Pressure (31 psi / 2.1 bar)	16.6 Watts CRR: 0.00498
Rolling Resistance Real tire width in mm: 30-32 = 33 psi/2.3 bar 33-35 = 30 psi/2.1 bar 36-38 = 27 psi/1.9 bar 39-42 = 25 psi/1.7 bar 43-46 = 23 psi/1.6 bar 47-50 = 21 psi/1.4 barExtra Low Air Pressure (23 psi / 1.6 bar)	Pro Data
The CX/Gravel section is a multi tire size section, air pressures have been adjusted to the measured casing width. All numbers are for a single tire at a speed of 29 km/h / 18 mph and a load of 42.5 kg / 94 lbs. Use the formula: RR (Watts) = CRR * speed (m/s) * load (N) to calculate rolling resistance at a given speed and load.

Puncture Resistance Test Results

Puncture Resistance Test Results (higher is better)
Total Puncture Score Tread	34 Points
Total Puncture Score Sidewall	Pro Data
Tread Puncture Force Sharp Needle	Pro Data
Tread Puncture Force Blunt Needle	Pro Data
Tread Total Tire Thickness	1.80 mm
Sidewall Puncture Force Sharp Needle	Pro Data
Sidewall Puncture Force Blunt Needle	Pro Data
Sidewall Total Tire Thickness	Pro Data

Hard Surface Static Grip Test Results

Static Grip Test Results
Wet Grip Average	71 Points
Wet Grip Center	Pro Data
Wet Grip Edge	Pro Data
Measured Knob Height Center	0.7 mm
Measured Knob Height Edge	2.7 mm
Grip in points = coefficient of friction * 100 CX/Gravel grip test rim width = 23.0 mm
Wet Grip Test and Off-Road Tires (info)

Conclusion

The Silca Protocol RCG-1 is an incredibly light, fast-rolling gravel bike tire, which makes it one of the most performant gravel bike tires on the market. Hard-surface wet grip falls in the middle of the pack, but given its tread pattern, with small knobs in the center and very large knobs along the edge of the tire, there isn't much to gain in this test. The weight, rolling resistance, and wet grip tests are the performance tests, and that's definitely where the Silca RCG-1 shines.

The shortcomings show up in the combined thickness of the tread and sidewalls, along with low to average puncture resistance in our tests.

There's also a lot to do about the pricing of Silca's new tires, and these are the most expensive tires we've bought to date. We think a lot of work went into these tires, as it's simply not possible to manufacture a competitive tire without putting in the effort one way or another.

The Silca RCG-1 is a race tire, and when it fits your needs, it's probably still one of the cheapest investments to gain performance.

RATING: 5.0 / 5
TEST VERDICT: Highly Recommended

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