CX/Gravel Tire Comparison:
Challenge Gravel Grinder 33 2020 vs
Rene Herse Steilacoom TC 38 2021

Contents and Test Summary

  1. Manufacturer Specifications
  2. Size and Weight Measurements
  3. Rolling Resistance Test Results
  4. Puncture Resistance Test Results
  5. Static Grip Test Results
  6. Conclusion
  • Challenge Gravel Grinder 33
  • Rene Herse Steilacoom TC 38
Performance compared to all other CX/Gravel tires
(100% is best)
Pro Members get 11-point radar charts



Manufacturer Specifications


Manufacturer Specifications
Brand ChallengeRene Herse
Model Gravel Grinder 33Steilacoom TC 38
Year 20202021
Supplied By Bought in storeBought in store
Full Review Full ReviewFull Review
New or Used NewNew
Mileage 0 km0 km
Price Range HighVery High
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Manufacturer Part Number 00535RF738TCX-LX-CP
EAN 8855627005356
TPI 260-
Compound
Bead FoldingFolding
ETRTO 33-62238-622
Specified Weight 0 grams445 grams
Min Air Pressure 35 psi psi
Max Air Pressure 75 psi75 psi
Made In Members OnlyMembers Only
Available Sizes 33-622 (700x33x)
36-622 (700x36c)
38-622 (700x38c)
Image 1
Challenge Gravel Grinder 33 2020
Rene Herse Steilacoom TC 38 2021
Image 2
Challenge Gravel Grinder 33 2020
Rene Herse Steilacoom TC 38 2021
Image 3
Challenge Gravel Grinder 33 2020
Rene Herse Steilacoom TC 38 2021
Image 4 Not AvailableNot Available

Size and Weight Measurements


Size and Weight Measurements
Model Gravel Grinder 33Steilacoom TC 38
Specified Weight 0 grams445 grams
Measured Weight 412 grams435 grams
Measured Width Casing 33 mm (un-round)35 mm (un-round)
Measured Width Tread 33 mm36 mm
Measured Height 31 mm (un-round)34 mm (un-round)
Measured Knob Height Center 0.7 mm2.9 mm
Measured Knob Height Edge 2.3 mm2.9 mm
Measured Casing Thickness Center 2.60 mm2.00 mm
Measured Total Thickness Sidewall Members OnlyMembers 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
Model Gravel Grinder 33Steilacoom TC 38
Spin Up Video YouTubeYouTube
Inner Tube Conti Cross28 (160 gr)None (30 ml sealant)
Measured Width 33 mm35 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
Members OnlyMembers 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
Members OnlyMembers 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
28.7 Watts
CRR: 0.00860
(40 psi / 2.8 bar)
23.1 Watts
CRR: 0.00692
(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 bar
Extra Low Air Pressure
33.9 Watts
CRR: 0.01016
(30 psi / 2.1 bar)
25.0 Watts
CRR: 0.00749
(30 psi / 2.1 bar)
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 Gravel Grinder 33Steilacoom TC 38
Total Puncture Score Tread 62 Points27 Points
Total Puncture Score Sidewall Members OnlyMembers Only
Tread Puncture Force Sharp Needle Members OnlyMembers Only
Tread Puncture Force Blunt Needle Members OnlyMembers Only
Tread Total Tire Thickness 2.6 mm2 mm
Sidewall Puncture Force Sharp Needle Members OnlyMembers Only
Sidewall Puncture Force Blunt Needle Members OnlyMembers Only
Sidewall Total Tire Thickness Members OnlyMembers Only

Static Grip Test Results


Static Grip Test Results (higher is better)
Model Gravel Grinder 33Steilacoom TC 38
Wet Grip Average 53 Points58 Points
Wet Grip Center Members OnlyMembers Only
Wet Grip Edge Members OnlyMembers Only
Measured Knob Height Center 0.7 mm2.9 mm
Measured Knob Height Edge 2.3 mm2.9 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 Gravel Grinder 33Steilacoom TC 38
Full Review Full ReviewFull Review
Verdict RecommendedRecommended
Rating 3.5 / 53.5 / 5
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  • Challenge Gravel Grinder 33
  • Rene Herse Steilacoom TC 38
Performance compared to all other CX/Gravel tires
(100% is fastest - lightest - highest - strongest)

Pro Members get 11-point radar charts