CX/Gravel Tire Test: Challenge Gravel Grinder 33

The Challenge Gravel Grinder is a cx/gravel bike tire with a diamond tread in the center and bigger knobs along the edge of the tire. From the outside, the Gravel Grinder looks like it should be faster rolling than the Challenge Grifo Pro (read our review) that we tested a couple of weeks back and which is a much knobbier tire.

Ad Buy Challenge Gravel Grinder at Amazon.com

Just like many other tires from Challenge, the Gravel Grinder is available in a lot of different versions. We're testing the handmade Pro version that comes with a tan-colored 260 TPI SuperPoly casing with an extra layer of PPS2 anti-puncture material under the tread.

The Gravel Grinder Pro is available in both a 33 and 36 mm wide version. We've tested the 33 mm version as we had a hard time finding the bigger version.

Manufacturer Specifications

Manufacturer Specs
Brand	Challenge
Model	Gravel Grinder
Year	2020
Supplied By	Bought in store
New or Used	New
Mileage	0 km
Price Range	High
Buy At	Ad Amazon.com
Manufacturer part number	00535
EAN	8855627005356
TPI	260
Compound
Bead	Folding
ETRTO	33-622
Specified Weight	0 grams
Max Air Pressure (psi)	75
Made In	Members Only
Available Sizes	33-622 (700x33x) 36-622 (700x36c)

Challenge Gravel Grinder 33 Test Results

Size, Weight, and Thickness Measurements

Size, Weight, and Thickness Measurements
Specified Weight	0 grams
Measured Weight	412 grams
Measured Width Casing	33 mm (un-round)
Measured Width Tread	33 mm
Measured Height	31 mm (un-round)
Measured Knob Height Center	0.7 mm
Measured Knob Height Edge	2.3 mm
Measured Total Thickness Center (excluding knobs)	2.60 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	Conti Cross28 (160 gr)
Measured Width	33 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 (60 psi / 4.1 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 (50 psi / 3.4 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 (40 psi / 2.8 bar)	28.7 Watts CRR: 0.00860
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 (30 psi / 2.1 bar)	33.9 Watts CRR: 0.01016
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	62 Points
Total Puncture Score Sidewall	Members Only
Tread Puncture Force Sharp Needle	15
Tread Puncture Force Blunt Needle	Members Only
Tread Total Tire Thickness	2.60 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	53 Points
Wet Grip Center	Members Only
Wet Grip Edge	Members Only
Measured Knob Height Center	0.7 mm
Measured Knob Height Edge	2.3 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 Gravel Grinder Pro scores very well in the tread puncture resistance test. The sidewalls on the other hand are quite weak which makes this an unbalanced tire in the puncture resistance department. Rolling Resistance isn't all that low although when compared to the fastest tires, the difference is manageable.

This can be a good tire if it fits your specific needs. We're not all that excited about this tire as the weak sidewalls can become a problem on gravel. Check the CX/Gravel overview page to compare for yourself.

Ad Buy Challenge Gravel Grinder at Amazon.com

RATING: 3.5 / 5
TEST VERDICT: Recommended

Comments