CX/Gravel Tire Test: Challenge Gravel Grinder 33

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  • Challenge Gravel Grinder 33
Performance compared to all other CX/Gravel tires
(100% is best)
Pro Members get 11-point radar charts



Challenge Gravel Grinder 33 road bike tire on a rolling resistance test machine

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.


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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
EAN8855627005356
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

Challenge Gravel Grinder 33  mountain bike tire on a rolling resistance test machine

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 bar
High 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 bar
Medium 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 bar
Low 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 bar
Extra 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

Challenge Gravel Grinder 33  mountain bike tire on a rolling resistance test machine
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


  • Challenge Gravel Grinder 33
Performance compared to all other CX/Gravel tires
(100% is fastest - lightest - highest - strongest)

Pro Members get 11-point radar charts

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:
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