CX/Gravel Tire Comparison:
Pirelli P Zero Race TLR RS SpeedCore 35 2026 vs
Silca Protocol RCR 38 2026

Contents and Test Summary

Manufacturer Specifications
Size and Weight Measurements
Rolling Resistance Test Results
Puncture Resistance Test Results
Static Grip Test Results
Conclusion

Pirelli P Zero Race TLR RS SpeedCore 35
Silca Protocol RCR 38

Performance compared to all other CX/Gravel tires
(100% is best)

Pro Members get 11-point radar charts

Ad Buy Pirelli P Zero Race TLR RS SpeedCore at Amazon.com

Manufacturer Specifications

Manufacturer Specifications
Brand	Pirelli	Silca
Model	P Zero Race TLR RS SpeedCore 35	Protocol RCR 38
Year	2026	2026
Supplied By	Bought in store	Bought in store
Full Review	Full Review	Full Review
New or Used	New	New
Mileage	0 km	0 km
Price Range	Very High	Very High
Buy At	Ad Amazon.com
Manufacturer Part Number	4353900	-
EAN	8019227435399	810093163397
TPI	120	120
Compound	SmartEvo 2	Pulsar Compound
Bead	Folding	Folding
ETRTO	35-622	38-622
Specified Weight	370 grams	354 grams
Min Air Pressure	psi	psi
Max Air Pressure	72 psi	58 psi
Made In	Pro Data	Pro Data
Available Sizes	26-622 (700x26c) 28-622 (700x28c) 30-622 (700x30c) 32-622 (700x32c) 35-622 (700x35c)	29-622 (700x29c) 34-622 (700x34c) 38-622 (700x38c)
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Size and Weight Measurements

Size and Weight Measurements
Model	P Zero Race TLR RS SpeedCore 35	Protocol RCR 38
Specified Weight	370 grams	354 grams
Measured Weight	392 grams	354 grams
Measured Width Casing	33 mm (un-round)	35 mm (un-round)
Measured Width Tread	31 mm	33 mm
Measured Height	Pro Data	Pro Data
Tire Circumference	Pro Data	Pro Data
Measured Knob Height Center	0.0 mm	0.0 mm
Measured Knob Height Edge	0.0 mm	0.0 mm
Measured Casing Thickness Center	2.90 mm	2.10 mm
Measured Total Thickness Sidewall	Pro Data	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
Model	P Zero Race TLR RS SpeedCore 35	Protocol RCR 38
Spin Up Video	YouTube	YouTube
Inner Tube	None (30 ml sealant)	None (30 ml sealant)
Measured Width	33 mm	35 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	Pro Data	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	Pro Data	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	13.6 Watts CRR: 0.00408 (40 psi / 2.8 bar)	15.6 Watts CRR: 0.00468 (40 psi / 2.8 bar)
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	Pro Data	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)
Model	P Zero Race TLR RS SpeedCore 35	Protocol RCR 38
Total Puncture Score Tread	50 Points	40 Points
Total Puncture Score Sidewall	Pro Data	Pro Data

Tread Puncture Force Sharp Needle	Pro Data	Pro Data
Tread Puncture Force Blunt Needle	Pro Data	Pro Data
Tread Total Tire Thickness	2.9 mm	2.1 mm
Sidewall Puncture Force Sharp Needle	Pro Data	Pro Data
Sidewall Puncture Force Blunt Needle	Pro Data	Pro Data
Sidewall Total Tire Thickness	Pro Data	Pro Data
NOTE: As of 2021, we've improved the puncture resistance tests and now provide 'Total Puncture Score' as the main puncture resistance indicator. Total Puncture Score: This score consists of Puncture Force Sharp Needle, Puncture Force Blunt Needle, and Total Tire Thickness. This value will give the best indication of real-life puncture resistance. Puncture Force Sharp Needle: Pre-2021, this score was known as 'Puncture Resistance'. On some tires with weakly bonded casing wires, the sharp needle can split the casing wires resulting in a lower score. Puncture Force Blunt Needle: The Blunt needle has a flat tip and won't split the casing wires. To puncture the tire, the blunt needle has to cut the casing wires. Total Tire Thickness: The puncture force tests are static and test the force required to puncture the casing and anti-puncture layers. To convert from a static lab test value to a more dynamic puncture resistance score, the thickness is used to calculate the total puncture resistance. More Info Close

Static Grip Test Results

Static Wet Grip Test and Off-Road Tires

It's critical to understand our static wet grip test works with a hard surface. This means the grip data is only directly useful for comparing tires on hard surfaces where the rubber compound creates the grip. Understanding the test results gets more difficult when grip is created by the knobs digging into the surface.

On soft surfaces (loose sand, grass, etc), almost all grip will be created by the knobs digging into the surface, and our test results will be of little use.

There will also be many surfaces where the total grip will be a combination of the tread compound grip and the grip provided by the knobs. Under these circumstances, the hard surface grip can still be a deciding factor.

Given these shortcomings, we feel our grip test, combined with the knob height measurements, will still be valuable information when comparing tires.

For more about our grip test, and how the knobby tread pattern affects the test results, we have more information here.

Static Grip Test Results (higher is better)
Model	P Zero Race TLR RS SpeedCore 35	Protocol RCR 38
Wet Grip Average	84 Points	85 Points
Wet Grip Center	Pro Data	Pro Data
Wet Grip Edge	Pro Data	Pro Data
Measured Knob Height Center	0.0 mm	0.0 mm
Measured Knob Height Edge	0.0 mm	0.0 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

Conclusion
Model	P Zero Race TLR RS SpeedCore 35	Protocol RCR 38
Full Review	Full Review	Full Review
Verdict	Highly Recommended	Highly Recommended
Rating	5.0 / 5	4.8 / 5
Buy At	Ad Amazon.com

Pirelli P Zero Race TLR RS SpeedCore 35
Silca Protocol RCR 38

Performance compared to all other CX/Gravel tires
(100% is fastest - lightest - highest - strongest)

Pro Members get 11-point radar charts

CX/Gravel Rolling Resistance Reviews
Brand	Model	Watts
Continental	Grand Prix 5000 S TR 35	11.4 W
Continental	Grand Prix 5000 S TR 32	12.8 W
Pirelli	P Zero Race TLR RS SpeedCore 32	13.2 W
Rene Herse	Snoqualmie Pass TC Extralight 44	13.5 W
Hutchinson	Caracal Race TLR (tan) 40	13.6 W
Pirelli	P Zero Race TLR RS SpeedCore 35	13.6 W
Michelin	Pro 5 TLR 35	13.8 W
Schwalbe	Pro One TLE Addix 38	14.3 W
Challenge	Strada Bianca Pro HTLR 40	14.8 W
Michelin	Pro 5 TLR 40	14.8 W
Ultradynamico	Cava Race 33	14.9 W
Hutchinson	Caracal Race TLR (black) 40	14.9 W
Continental	Grand Prix 5000 All Season TR (cream) 35	15.0 W
Schwalbe	Pro One TLE Addix 34	15.5 W
Silca	Protocol RCR 38	15.6 W
Continental	Grand Prix 5000 All Season TR 35	15.6 W
Hutchinson	Caracal Race TLR (tan) 45	15.7 W
Schwalbe	G-One RS Pro (black) 40	15.7 W
Schwalbe	G-One RS Super Race 35	15.7 W
Challenge	Strada Bianca Pro HTLR 36	15.7 W
Pirelli	P Zero Race TLR SpeedCore 32	15.8 W
Continental	Terra Competition Race Rapid 45	15.8 W
Hutchinson	Caracal Race TLR (tan) 50	15.8 W
Hutchinson	Caracal Race GridSkin 40	15.8 W
Schwalbe	Pro One TLE Addix 32	15.8 W
View All

Road Bike Rolling Resistance Reviews
Excludes previous models/discontinued tires Visit the road bike overview to view all
Brand	Model	Watts
Vittoria	Corsa Pro Speed TLR 28	6.7 W
Vittoria	Corsa Pro Speed TLR WR 29	7.0 W
Vittoria	Corsa Pro Speed TLR WR (on 22/23 mm rims) 29	7.4 W
Veloflex	Record TLR 25	7.7 W
Continental	Archetype 30	8.0 W
Continental	Grand Prix 5000 TT TR 28	8.3 W
Continental	Grand Prix 5000 TT TR (TdF) 25	8.4 W
Pirelli	P Zero Race TLR SL-R 28	8.4 W
Pirelli	P Zero Race TLR SL-R 30	8.5 W
Continental	Grand Prix 5000 TT TR 30	8.5 W
Schwalbe	Pro One TT TLE Addix 25	9.0 W
Enve	SES Raceday 29	9.3 W
Specialized	Cotton TLR 28	9.3 W
Tufo	Comtura Prima TT 28	9.3 W
Pirelli	P Zero Race TLR RS SpeedCore 30	9.7 W
Continental	Grand Prix 5000 S TR 28	9.7 W
Pirelli	P Zero Race TLR RS SpeedCore (retro) 28	10.0 W
Continental	Grand Prix 5000 S TR 30	10.0 W
Continental	Grand Prix 5000 S TR 25	10.1 W
Panaracer	Agilest Fast TLR 28	10.1 W
Goodyear	Eagle F1 SuperSport R TLC 28	10.2 W
Michelin	Power Cup TLR 28	10.3 W
Continental	Aero 111 29	10.5 W
Pirelli	P Zero Race TLR RS SpeedCore 28	10.5 W
Challenge	Criterium RS (white) 30	10.5 W
View All

Mountain Bike Rolling Resistance Reviews
Excludes previous models/discontinued tires Visit the MTB overview to view all
Brand	Model	Watts
Schwalbe	G-One Speed Pro	11.9 W
Schwalbe	Thunder Burt Super Ground Addix Speed	15.7 W
Pirelli	Scorpion XC RH Race Lite Team Edition	16.7 W
Schwalbe	Thunder Burt Super Race Addix Speed	17.3 W
Schwalbe	Rocket Ron LiteSkin Addix Speed	18.1 W
Schwalbe	Thunder Burt Super Race Addix Speed	18.1 W
Continental	Race King Protection (E-25)	18.2 W
Schwalbe	Thunder Burt Super Ground Addix Speed	18.6 W
Schwalbe	Rick XC Pro Speed	19.0 W
Schwalbe	Racing Ralph Super Ground Addix Speed	19.0 W
Continental	Speed King II RaceSport	19.1 W
Vittoria	Terreno XC Race	19.1 W
Schwalbe	Rick XC Pro SpeedGrip	19.3 W
Schwalbe	Racing Ray Super Race	19.3 W
Schwalbe	G-One RX Pro (black) 55	19.4 W
Schwalbe	G-One RS Pro (black) 55	20.1 W
Continental	Dubnital Race Rapid	20.2 W
Schwalbe	Racing Ray Super Ground Addix SpeedGrip	20.4 W
Schwalbe	Racing Ralph LiteSkin Addix Speed	20.5 W
Continental	Race King Protection (tanwall)	20.6 W
Continental	Dubnital Race Rapid	20.6 W
Schwalbe	Rocket Ron Super Race Addix Speed	20.8 W
Vittoria	Peyote XC Race	21.0 W
Schwalbe	Rocket Ron Super Race Addix Speed 2026	21.3 W
Vittoria	Peyote XC Race	21.3 W
View All

Touring Bike Rolling Resistance Reviews
Brand	Model	Watts
Compass	Bon Jon Pass TC	15.6 W
Continental	Grand Prix Urban	16.9 W
Schwalbe	Marathon Almotion (OneStar)	17.1 W
Vittoria	Voyager Hyper	17.7 W
Continental	Contact Urban	18.4 W
Schwalbe	Marathon Efficiency	18.5 W
Schwalbe	Marathon Supreme	19.1 W
Schwalbe	Marathon Almotion Addix	19.4 W
Schwalbe	Marathon Almotion TLE Addix	19.7 W
Panaracer	Pasela PT (ProTite)	20.6 W
Continental	Sport Contact II	20.6 W
Schwalbe	Marathon (GreenGuard)	21.3 W
Schwalbe	Energizer Plus	21.5 W
Continental	Pure Contact	21.9 W
CST	E-Series Reach	21.9 W
Schwalbe	Green Marathon	22.4 W
Continental	Top Contact II	24.2 W
Continental	Urban Taraxagum	24.2 W
Continental	Contact II	24.3 W
Schwalbe	Marathon Racer	24.6 W
Schwalbe	Kojak	24.8 W
Continental	City Ride II	25.1 W
Schwalbe	Marathon Plus	25.5 W
Schwalbe	Marathon Mondial Evo	26.7 W
Vredestein	Perfect-E	27.3 W
View All