CX/Gravel Tire Test: WTB Vulpine S TCS Light SG 40

The WTB Vulpine S is a semi-slick gravel bike tire, and they claim it is their fastest gravel tire. The Vulpine S is very similar to the popular Vulpine but features a fully continuous rubber strip in the center of the tire. WTB claims that the slick centerline reduces rolling resistance and wear. We agree about the wear, but from our experience, the tread pattern often has little to do with total rolling resistance.

It has been a long time since we tested a tire from WTB, so it's always good to take another look at a new tire from a brand. We see WTB as one of the pioneers in gravel bike tires because they were already offering a wide selection before most major brands entered the market. Recently, we have seen big brands introduce one tire after another, making the gravel segment extremely competitive.

The Vulpine S is available in 40-622 and 45-622 versions. Both versions have the characteristic brown sidewalls typical of WTB, or you can choose simple black sidewalls.

Manufacturer Specifications

Manufacturer Specs
Brand	WTB
Model	Vulpine S TCS Light SG
Year	2025
Supplied By	Bought in store
New or Used	New
Mileage	0 km
Price Range	High
Buy At
Manufacturer part number	W010-1061
TPI	120
Compound	Dual DNA
Bead	Folding
ETRTO	40-622
Specified Weight	500 grams
Max Air Pressure (psi)	50
Made In	Pro Data
Available Sizes	40-622 (700x40c) 45-622 (700x45c)

WTB Vulpine S TCS Light SG 40 Test Results

Size, Weight, and Thickness Measurements

Size, Weight, and Thickness Measurements
Specified Weight	500 grams
Measured Weight	497 grams
Measured Width Casing	38 mm (un-round)
Measured Width Tread	39 mm
Measured Height	35 mm (un-round)
Measured Knob Height Center	0.0 mm
Measured Knob Height Edge	1.8 mm
Measured Total Thickness Center (excluding knobs)	3.40 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	38 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 (54 psi / 3.7 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 (45 psi / 3.1 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 (36 psi / 2.6 bar)	30.7 Watts CRR: 0.00920
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 (27 psi / 1.9 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	56 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	3.40 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	68 Points
Wet Grip Center	Pro Data
Wet Grip Edge	Pro Data
Measured Knob Height Center	0.0 mm
Measured Knob Height Edge	1.8 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

In our tests, the WTB Vulpine S doesn't perform particularly impressively. Unfortunately, we see a very high rolling resistance, which we consider a significant drawback for a semi-slick tire, as most people choose this type of tire for speed. However, we do see decent performance in the other tests, particularly the puncture resistance of the tread, which stands out as much better than the average gravel bike tire.

As we mentioned, we find the high rolling resistance unsuitable for a semi-slick tire, and we cannot recommend the Vulpine S. There are many tires that simply perform better in all our tests, so we recommend checking out our CX/Gravel Tire Overview where you can compare a wide selection of gravel bike tires.

RATING: 2.5 / 5
TEST VERDICT: Not Recommended

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