ETENWOLF S1 Portable Tire Inflator Pressure Accuracy Test Report — Unit S1-2# (Road Bike & Mountain Bike)

Document Overview

Key Findings The ETENWOLF S1-2# portable tire inflator completed a full pressure accuracy and pressure-retention evaluation on 2025-08-15, covering road-bike inflation scenarios from 15 PSI to 110 PSI and mountain-bike scenarios from 15 PSI to 60 PSI. All stop-pressure readings landed within ±1 PSI of…

Document type

Test Report

Prepared by

Daniel Wright

Published

July 22, 2026

Last reviewed

July 22, 2026

Topics

Motor Performance

Key Findings

The ETENWOLF S1-2# portable tire inflator completed a full pressure accuracy and pressure-retention evaluation on 2025-08-15, covering road-bike inflation scenarios from 15 PSI to 110 PSI and mountain-bike scenarios from 15 PSI to 60 PSI. All stop-pressure readings landed within ±1 PSI of the preset target, and 10-second post-stop readings confirmed stable pressure retention across every tested interval.

• Product: ETENWOLF S1-2# Portable Tire Inflator
• Test date: 2025-08-15
• Tester code: BTK
• Tire types: Road bicycle (公路自行车) and mountain bicycle (山地自行车)
• Preset pressure range tested: 15 PSI – 110 PSI (road); 15 PSI – 60 PSI (mountain)
• Maximum accuracy deviation observed: +0.5 PSI / −0.9 PSI
• Maximum retention deviation observed: −0.9 PSI over 10 seconds
• Overall verdict: PASS — all readings within acceptable tolerance

Test Overview

Test Equipment & Setup

Test Procedure

1. Pre-test: Confirm tire is fully deflated or at a known baseline pressure matching the lower bound of the test interval.
2. Setup: Connect the S1-2# inflator to the valve stem. Enter the target preset pressure on the device.
3. Inflation: Start inflation. The device inflates from the lower-bound pressure to the preset target and auto-stops.
4. Stop-pressure recording: Immediately record the displayed pressure at the moment of auto-stop (column: Stop Pressure).
5. 10-second retention recording: Wait 10 seconds without disconnecting; record the displayed pressure (column: Stop+10 s Pressure).
6. Delta calculations:
   • Retention delta = Stop+10 s Pressure − Stop Pressure (negative value indicates natural bleed-down).
   • Accuracy delta = Stop+10 s Pressure − Preset Pressure (measures how close final pressure is to the user’s target).
7. Repeat: Each numbered row is an independent inflation run with a fresh starting pressure matching the stated lower bound.
8. Post-test: Deflate tire, disconnect inflator, and proceed to the next interval.

Acceptance criteria: Stop pressure must be within ±1.0 PSI of the preset target; accuracy delta (10 s reading vs. preset) must be within ±1.0 PSI.

Test Data & Results

Section A — Road Bicycle (公路自行车) · Unit S1-2#

Section B — Mountain Bicycle (山地自行车) · Unit S1-2#

Observations: All 38 road-bicycle runs and all 11 mountain-bicycle runs stayed within the ±1.0 PSI acceptance threshold for both stop-pressure accuracy and 10-second retention. The largest single accuracy deviation was +0.50 PSI (road bike row 37, 80–90 PSI interval). The largest retention loss was −0.90 PSI (road bike row 12, 40–110 PSI interval). Mountain-bike readings showed a consistent slight under-stop pattern (accuracy deltas uniformly negative), suggesting the sensor cuts off marginally early at lower pressures — still within spec. No anomalous or out-of-tolerance readings were recorded.

Conclusion

Document Information

Frequently Asked Questions

How accurate is the ETENWOLF S1 tire inflator’s auto-stop feature?

Across 49 test runs covering road-bike presets from 15 PSI to 110 PSI and mountain-bike presets from 15 PSI to 60 PSI, the S1-2# unit stopped within ±1.0 PSI of every preset target. The largest deviation recorded was +0.50 PSI above the target on the 80–90 PSI road-bike interval. In everyday use this means the tire will be within one PSI of your chosen pressure every time the inflator stops.

Does the ETENWOLF S1 lose pressure after it stops inflating?

A small amount of bleed-down is normal as the valve closes and the hose depressurizes. In testing, the 10-second post-stop readings showed a maximum drop of −0.90 PSI from the stop reading (road-bike 40–110 PSI run). All 10-second readings remained within ±1.0 PSI of the original preset target, confirming the tire retains its target pressure after the inflator is disconnected.

Can the ETENWOLF S1 handle both road bike and mountain bike tires?

Yes. The S1-2# was tested on road bicycle tires up to 110 PSI and mountain bicycle tires up to 60 PSI, spanning the full practical pressure range for both disciplines. All runs passed the accuracy and retention criteria, confirming the inflator is suitable for both tire types without any mode switching.

What is the difference between S1-1# and S1-2# in the accuracy test results?

S1-1# and S1-2# are two production units of the same ETENWOLF S1 model tested in the same workbook. Comparing their sheets allows quality engineers to confirm unit-to-unit consistency. Both units were evaluated on identical road-bike and mountain-bike inflation intervals. The sibling-sheet results for S1-1# can be found in the related articles linked below.

Related Products

• ETENWOLF S1 Portable Tire Inflator — Product Page
• S1-1# Road Bike & Mountain Bike Pressure Accuracy Test Report — sibling sheet S1-1#-自行车-山地车
• S1-1# Basketball Pressure Accuracy Test Report — sibling sheet S1-1#-蓝球
• S1-2# Basketball Pressure Accuracy Test Report — sibling sheet S1-2#-蓝球