CX/Gravel Tire Test: Panaracer GravelKing Slick 40

Panaracer recently updated the regular GravelKing, which is sometimes also called GravelKing Slick, and it's now available in three different casing versions. The standard GravelKing we have on test today has the most versatile casing construction and is made for gravel bikers looking for balanced performance and protection. Also available is the R casing, made for all-out performance, and a + (Plus) casing, which comes with additional protection.

All casing constructions now come with a special TuffTex layer developed by Panaracer that adds protection and better sealing capabilities. The beads have been updated with a unique BeadLock bead that makes it much easier to inflate the tire even when compressed air is unavailable. This is pretty much a tubeless-ready 2.0 construction, as while the original GravelKings were available in a tubeless-ready casing, sealing and inflating weren't always that easy.

The compound also sees an update. The updated GravelKings now come with a new "ZSG Gravel" compound, a variation of Panaracer's ZSG compound, which we find on many of their high-end tires. The previous editions of the GravelKings could have been better performers in our wet grip test, and we always thought the compound could use improvement in that regard.

We have already tested the GravelKing in the R casing (read our review), and now we will examine how the standard GravelKing compares to the R version and the previous generation "TLC" GravelKing (read our review). We tested the 40 mm version of the GravelKing, which allows us to compare the new GravelKing with a large selection of tires we have tested previously.

Manufacturer Specifications

Manufacturer Specs
Brand	Panaracer
Model	GravelKing Slick
Year	2025
Supplied By	Bought in store
New or Used	New
Mileage	0 km
Price Range	High
Buy At
Manufacturer part number	RF740-FK-D2
TPI	120
Compound	ZSG Gravel
Bead	Folding
ETRTO	40-622
Specified Weight	420 grams
Max Air Pressure (psi)	75
Made In	Members Only
Available Sizes	26-622 (700x26c) 28-622 (700x28c) 30-622 (700x30c) 35-622 (700x35c) 40-622 (700x40c) 38-584 (650x38b) 42-584 (650x42b) 48-622 (650x48b)

Panaracer GravelKing Slick 40 Test Results

Size, Weight, and Thickness Measurements

Size, Weight, and Thickness Measurements
Specified Weight	420 grams
Measured Weight	415 grams
Measured Width Casing	40 mm (un-round)
Measured Width Tread	39 mm
Measured Height	36 mm (un-round)
Measured Knob Height Center	0.2 mm
Measured Knob Height Edge	0.2 mm
Measured Total Thickness Center (excluding knobs)	2.40 mm
Measured Total Thickness Sidewall	Members Only
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	40 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 (50 psi / 3.4 bar)	Members Only
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 (42 psi / 2.9 bar)	Members Only
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 (33 psi / 2.3 bar)	18.4 Watts CRR: 0.00552
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 (25 psi / 1.7 bar)	21.5 Watts CRR: 0.00644
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	35 Points
Total Puncture Score Sidewall	Members Only
Tread Puncture Force Sharp Needle	Members Only
Tread Puncture Force Blunt Needle	Members Only
Tread Total Tire Thickness	2.40 mm
Sidewall Puncture Force Sharp Needle	Members Only
Sidewall Puncture Force Blunt Needle	Members Only
Sidewall Total Tire Thickness	Members Only

Hard Surface Static Grip Test Results

Static Grip Test Results
Wet Grip Average	61 Points
Wet Grip Center	Members Only
Wet Grip Edge	Members Only
Measured Knob Height Center	0.2 mm
Measured Knob Height Edge	0.2 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 new GravelKing with standard casing finally allows us to compare the latest generation GravelKing with the previous generation "GravelKing TLC". The new GravelKing has progressed in some areas, particularly from a user-friendliness perspective; the tubeless setup is much easier, and the tire retains air much better.

Unfortunately, we do see that this has come at the cost of performance; the sturdier construction inevitably results in more weight and more rolling resistance. We also notice that the compound has remained virtually the same, although it now has a slightly different name: "ZSG Gravel compound" instead of "ZSG compound."

Surprisingly, the performance of the GravelKing in standard casing is virtually the same as that of the lighter R version. We were somewhat prepared for this because we saw the same pattern with the new GravelKing X1, which we also tested in both R and standard casing. The advantage of the R casing remains its weight since it is considerably lighter.

If you want to stay close to the performance of the old GravelKing TLC, we recommend always opting for the R casings of the new GravelKings.

Some interesting GravelKing comparisons:

GravelKing Slick Vs GravelKing Slick R
GravelKing Slick (new) Vs GravelKing TLC (old)

RATING: 3.8 / 5
TEST VERDICT: Recommended

Comments