ETENWOLF S0 Portable Bike Pump Pressure Accuracy Test Report — Road & Mountain Bike (Unit #2)

Document Overview

Key Findings The ETENWOLF S0 Unit #2 passed pressure accuracy testing across all road bike and mountain bike inflation scenarios, with stop-pressure deviations consistently within ±0.6 PSI of the preset target and 10-second hold pressures confirming stable pressure retention throughout the tested range. Test Date:…

Document type

Test Report

Prepared by

Daniel Wright

Published

July 22, 2026

Last reviewed

July 22, 2026

Topics

Motor Performance

Key Findings

The ETENWOLF S0 Unit #2 passed pressure accuracy testing across all road bike and mountain bike inflation scenarios, with stop-pressure deviations consistently within ±0.6 PSI of the preset target and 10-second hold pressures confirming stable pressure retention throughout the tested range.

• Test Date: 2025-08-03
• Product: S0-2# (ETENWOLF S0 Portable Bike Pump, Unit #2)
• Tire Types Tested: Road Bike (公路自行车), Mountain Bike (山地自行车)
• Preset Pressure Range Tested: 15–110 PSI (Road Bike); 15–60 PSI (Mountain Bike)
• Maximum Accuracy Deviation Observed: +0.6 PSI (Row 29, Road Bike, 0→100 PSI)
• Maximum Pressure Retention Loss (10 s): −0.6 PSI (Row 29, Road Bike, 0→100 PSI)
• Overall Verdict: All readings within acceptable accuracy tolerance

Test Overview

Test Equipment & Setup

Test Procedure

1. Pre-test: Confirm tire is fully deflated to the starting pressure specified in the inflation range column (e.g. 0 PSI or the lower bound of a mid-range test).
2. Setup: Connect the ETENWOLF S0 pump to the tire valve. Set the target preset pressure on the pump display to the value in the “Preset Pressure (PSI)” column.
3. Inflation: Start the pump and allow it to inflate until auto-shutoff is triggered.
4. Stop Pressure Reading: Immediately record the pressure displayed at the moment of auto-shutoff. This is the “Stop Pressure (PSI)” value.
5. 10-Second Hold: Wait 10 seconds without disconnecting the pump or valve, then record the pressure again. This is the “Stop 10s Pressure (PSI)” value.
6. Calculate Retention Delta: Subtract Stop Pressure from Stop 10s Pressure: Δ(Retention) = Stop 10s − Stop Pressure.
7. Calculate Accuracy Delta: Subtract Preset Pressure from Stop Pressure: Δ(Accuracy) = Stop Pressure − Preset Pressure.
8. Repeat for each inflation range row in the test matrix.
9. Post-test: Record all values in the test log and verify no row exceeds the acceptance threshold.
10. Acceptance Criteria: All accuracy deltas and retention deltas must fall within the product specification tolerance (observed maximum ±1.0 PSI across the tested range).

Test Data & Results

Road Bike (公路自行车) — S0-2#

Mountain Bike (山地自行车) — S0-2#

Observations: All 46 total measurements (35 road bike + 11 mountain bike) remained within the pressure accuracy tolerance band. The largest positive accuracy delta was +0.6 PSI (Road Bike, Row 34, 0→60 PSI second run), and the largest negative accuracy delta was −0.5 PSI (Mountain Bike, Row 6, 35→40 PSI). Pressure retention over 10 seconds was consistently stable, with the maximum retention loss of −0.6 PSI recorded on Road Bike Row 29 (0→100 PSI). Mountain bike results show tighter deviations in the lower pressure range, consistent with lower absolute pressures and reduced inertia overshoot.

Conclusion

Document Information

Frequently Asked Questions

How accurate is the ETENWOLF S0 pump when inflating road bike tires to 110 PSI?

In unit #2 testing across all road bike inflation scenarios targeting 110 PSI, the stop pressure deviated by no more than +0.6 PSI from the preset. After a 10-second hold, the pressure remained within 0.3 PSI of the stop reading, confirming reliable auto-shutoff accuracy at high pressures.

What pressure accuracy can I expect from the S0 when inflating mountain bike tires?

Across 11 mountain bike test runs (15–60 PSI range), the S0 unit #2 held accuracy deltas between −0.5 PSI and +0.1 PSI. The 10-second retention loss never exceeded −0.5 PSI, showing stable pressure delivery for typical mountain bike tire pressures.

Does the ETENWOLF S0 accurately stop at mid-range pressures, or only at maximum PSI?

The S0 was tested at every 5 PSI increment from 15 PSI up to 110 PSI for road bikes, including mid-range top-up scenarios starting from 60, 70, 80, or 90 PSI. All mid-range shutoffs were accurate within ±0.5 PSI of the preset target, confirming the auto-stop works reliably across the full operating range — not just at maximum pressure.

Is this pressure accuracy test specific to one unit, or does it represent all S0 pumps?

This report covers unit #2 (S0-2#) tested on 2025-08-03. A parallel accuracy test was conducted on unit #1 (S0-1#) under the same conditions. Both unit reports are available for review — see the Related Products section below for links to the S0-1# road bike and basketball test sheets.

Related Products

Explore the full ETENWOLF S0 accuracy test series and related products:

• ETENWOLF S0 Portable Bike Pump — Product Page
• S0 Unit #1 — Basketball Pressure Accuracy Test (S0-1#-蓝球)
• S0 Unit #1 — Road & Mountain Bike Pressure Accuracy Test (S0-1#-自行车-山地车)
• S0 Unit #2 — Basketball Pressure Accuracy Test (S0-2#-蓝球)