ETENWOLF S3 Cordless Tire Inflator Pressure Accuracy Test Report — Unit #2 (Road Bike & Mountain Bike)

Document Overview

Key Findings The ETENWOLF S3 cordless tire inflator (Unit #2) completed a full pressure accuracy test on 2025-06-30, covering road bicycle inflate ranges from 15 PSI to 110 PSI and mountain bicycle ranges from 15 PSI to 60 PSI. All stop-pressure and 10-second hold readings…

Document type
Test Report
Prepared by
Daniel Wright
Published
Last reviewed
Topics
Motor Performance

Key Findings

The ETENWOLF S3 cordless tire inflator (Unit #2) completed a full pressure accuracy test on 2025-06-30, covering road bicycle inflate ranges from 15 PSI to 110 PSI and mountain bicycle ranges from 15 PSI to 60 PSI. All stop-pressure and 10-second hold readings remained within ±1.3 PSI of the preset target across every test case.

  • Test date: 2025-06-30
  • Unit under test: S3-2#
  • Tire types: Road bicycle (公路自行车), Mountain bicycle (山地自行车)
  • Road bike test cases: 38 rows (PSI presets 15–110, incremental and segmented ranges)
  • Mountain bike test cases: 11 rows (PSI presets 15–60, incremental ranges)
  • Maximum pressure deviation (accuracy delta): +0.8 PSI / −0.4 PSI (road); +0.3 PSI / −0.3 PSI (mountain)
  • Maximum retention loss (10 s hold delta): −1.3 PSI (road); −0.6 PSI (mountain)
  • Overall verdict: Pass — all readings within acceptable accuracy tolerance

Test Overview

Field Detail
Test Type Pressure Accuracy & Pressure Retention
Report / Sheet S3-2#自行车-山地车 (Sheet 4 of 6)
Test Date 2025-06-30
Tester Code BTK
Product ETENWOLF S3 Cordless Tire Inflator
Unit Under Test S3-2#
Manufacturer ETENWOLF
Product Line Inflation Tools
Tire Types Tested Road Bicycle (公路自行车), Mountain Bicycle (山地自行车)
Source File S3-精度测试-2025.6.30.xlsx

Test Equipment & Setup

Parameter Value
Unit Under Test ETENWOLF S3 Cordless Tire Inflator, Unit #2 (S3-2#)
Pressure Unit PSI
Preset Pressure Range — Road Bike 15 PSI to 110 PSI
Preset Pressure Range — Mountain Bike 15 PSI to 60 PSI
Retention Measurement Interval 10 seconds after auto-stop
Test Ambient Identifier BTK
Metrics Recorded Inflate range (PSI), Preset pressure, Stop pressure, 10 s hold pressure, Retention delta, Accuracy delta

Test Procedure

  1. Pre-test: Confirm unit S3-2# is fully charged and the tire valve adapter is securely connected to the test tire.
  2. Set preset pressure: Enter the target PSI value on the S3 digital display for the specified inflate range.
  3. Inflate: Start inflation from the lower bound of the specified range. The unit auto-stops when the internal sensor detects the preset pressure.
  4. Record stop pressure: Immediately read and record the displayed pressure at auto-stop (停止气压).
  5. Wait 10 seconds: Hold the connection and record the pressure again after 10 seconds (停止10s气压).
  6. Calculate retention delta: Subtract the preset pressure from the 10 s pressure (差值（保压）= 停止10s气压 − 预设气压).
  7. Calculate accuracy delta: Subtract the preset pressure from the stop pressure (差值(精度）= 停止气压 − 预设气压).
  8. Repeat for all specified inflate ranges across both road bicycle and mountain bicycle tire profiles.
  9. Post-test: Review all delta values against acceptance criteria.

Acceptance Criteria: Stop pressure and 10 s hold pressure must remain within ±2.0 PSI of the preset target. All accuracy and retention delta values must not exceed ±2.0 PSI.

Test Data & Results

Road Bicycle (公路自行车) — Unit S3-2#

# Tire Type Inflate Range (PSI) Preset (PSI) Stop Pressure (PSI) 10 s Hold (PSI) Retention Delta (PSI) Accuracy Delta (PSI) Remarks
1 Road Bicycle 0–15 15 16 15.8 −0.20 +0.80
2 Road Bicycle 15–110 110 110.9 109.6 −1.30 −0.40
3 Road Bicycle 0–20 20 21.1 20.5 −0.60 +0.50
4 Road Bicycle 20–110 110 110 109.7 −0.30 −0.30
5 Road Bicycle 0–25 25 26.2 25.6 −0.60 +0.60
6 Road Bicycle 25–110 110 111 109.9 −1.10 −0.10
7 Road Bicycle 0–30 30 30.4 30.1 −0.30 +0.10
8 Road Bicycle 30–110 110 110.8 109.9 −0.90 −0.10
9 Road Bicycle 0–35 35 35.8 35 −0.80 0.00
10 Road Bicycle 35–110 110 110.5 109.6 −0.90 −0.40
11 Road Bicycle 0–40 40 41 40.1 −0.90 +0.10
12 Road Bicycle 40–110 110 110.9 109.9 −1.00 −0.10
13 Road Bicycle 0–45 45 45.6 44.9 −0.70 −0.10
14 Road Bicycle 45–110 110 110.9 109.9 −1.00 −0.10
15 Road Bicycle 0–50 50 50.9 50.3 −0.60 +0.30
16 Road Bicycle 50–110 110 111 109.9 −1.10 −0.10
17 Road Bicycle 0–55 55 55.8 54.9 −0.90 −0.10
18 Road Bicycle 55–110 110 110.8 109.6 −1.20 −0.40
19 Road Bicycle 0–60 60 61 60.1 −0.90 +0.10
20 Road Bicycle 60–110 110 110.9 109.7 −1.20 −0.30
21 Road Bicycle 0–70 70 71.2 70.1 −1.10 +0.10
22 Road Bicycle 70–110 110 110 109.9 −0.10 −0.10
23 Road Bicycle 0–85 85 85.7 84.8 −0.90 −0.20
24 Road Bicycle 85–110 110 110.9 109.9 −1.00 −0.10
25 Road Bicycle 0–90 90 90.9 89.7 −1.20 −0.30
26 Road Bicycle 90–110 110 111 110.2 −0.80 +0.20
27 Road Bicycle 0–95 95 95.8 94.7 −1.10 −0.30
28 Road Bicycle 95–110 110 111.2 110.2 −1.00 +0.20
29 Road Bicycle 0–100 100 100.9 99.9 −1.00 −0.10
30 Road Bicycle 100–110 110 110.8 110 −0.80 0.00
31 Road Bicycle 0–105 105 105.7 105 −0.70 0.00
32 Road Bicycle 105–110 110 111 110.3 −0.70 +0.30
33 Road Bicycle 0–110 110 110.9 110 −0.90 0.00
34 Road Bicycle 0–60 60 61 60 −1.00 0.00
35 Road Bicycle 60–70 70 71 70.1 −0.90 +0.10
36 Road Bicycle 70–80 80 80.6 79.9 −0.70 −0.10
37 Road Bicycle 80–90 90 91 89.9 −1.10 −0.10
38 Road Bicycle 90–100 100 100.9 99.9 −1.00 −0.10

Observations (Road Bicycle): All 38 road bike test cases show auto-stop pressures within +1.2 / −0.0 PSI of preset. The 10-second hold readings confirm consistent retention, with the largest retention loss being −1.3 PSI (row 2, 15–110 PSI range). Accuracy delta ranges from −0.4 PSI to +0.8 PSI across all cases.

Mountain Bicycle (山地自行车) — Unit S3-2#

# Tire Type Inflate Range (PSI) Preset (PSI) Stop Pressure (PSI) 10 s Hold (PSI) Retention Delta (PSI) Accuracy Delta (PSI) Remarks
1 Mountain Bicycle 0–15 15 15.2 14.7 −0.50 −0.30
2 Mountain Bicycle 15–20 20 20.4 20.1 −0.30 +0.10
3 Mountain Bicycle 20–25 25 25.5 25 −0.50 0.00
4 Mountain Bicycle 25–30 30 30.4 30.1 −0.30 +0.10
5 Mountain Bicycle 30–35 35 35.2 34.9 −0.30 −0.10
6 Mountain Bicycle 35–40 40 40.6 40.1 −0.50 +0.10
7 Mountain Bicycle 40–45 45 45.6 45.1 −0.50 +0.10
8 Mountain Bicycle 45–50 50 50.7 50.1 −0.60 +0.10
9 Mountain Bicycle 50–55 55 55.5 55.1 −0.40 +0.10
10 Mountain Bicycle 55–60 60 60.7 60.3 −0.40 +0.30
11 Mountain Bicycle 0–60 60 60.7 60.1 −0.60 +0.10

Observations (Mountain Bicycle): All 11 mountain bike test cases pass comfortably. The accuracy delta is tightly bounded between −0.3 PSI and +0.3 PSI. The maximum retention loss is −0.6 PSI, notably tighter than the road bike profile, consistent with the lower operating pressure range (15–60 PSI).

Conclusion

Item Detail
Unit Tested ETENWOLF S3 Cordless Tire Inflator — S3-2#
Test Scope Pressure accuracy and 10-second retention across road bicycle and mountain bicycle inflate profiles
Road Bike Preset Range 15 PSI to 110 PSI (38 test cases)
Mountain Bike Preset Range 15 PSI to 60 PSI (11 test cases)
Max Accuracy Delta — Road +0.80 PSI / −0.40 PSI
Max Accuracy Delta — Mountain +0.30 PSI / −0.30 PSI
Max Retention Loss — Road −1.30 PSI
Max Retention Loss — Mountain −0.60 PSI
Acceptance Threshold ±2.0 PSI
Verdict PASS — All 49 test cases within tolerance

Document Information

Role Name Code / Reference
Tester BTK BTK
Source File S3-精度测试-2025.6.30.xlsx Sheet: S3-2#自行车-山地车 (Index 4 of 6)
Report Date 2025-06-30 —
Published By Daniel Wright Author ID: 3

Frequently Asked Questions

What pressure accuracy can I expect from the ETENWOLF S3 on a road bicycle?

In this unit #2 test, the S3 auto-stopped within +0.8 PSI to −0.4 PSI of every preset target across 38 road bike inflate sequences, from 15 PSI up to 110 PSI. After a 10-second hold, pressure retention loss never exceeded 1.3 PSI.

Is the ETENWOLF S3 accurate enough for mountain bike tires?

Yes. Across 11 mountain bike test cases (15–60 PSI), the S3 unit #2 held accuracy within ±0.3 PSI of each preset and lost no more than 0.6 PSI over a 10-second hold, making it well-suited for the tighter tolerances typical of tubeless mountain bike setups.

How does the S3 auto-stop feature work during inflation?

The S3 continuously monitors internal pressure while inflating. When the sensor detects that the line pressure matches the user-set preset, the motor cuts off automatically. The small overshoot seen in test data (typically 0.2–1.2 PSI above preset at stop) is normal and dissipates within seconds as pressure equalizes between the hose and tire.

What is the difference between the accuracy delta and the retention delta in this report?

The accuracy delta (差值精度) is the stop pressure minus the preset — it measures how precisely the unit hits its target at the moment of auto-stop. The retention delta (差值保压) is the 10-second hold pressure minus the preset — it measures how well pressure is maintained once inflation ends. A negative retention delta indicates minor pressure bleed-back into the tire or hose after the motor stops, which is expected behavior.

Related Products

The ETENWOLF S3 has been tested across multiple unit samples and tire types. Review the sibling test reports from the same test batch below:

  • ETENWOLF S3 Cordless Tire Inflator — Product Page
  • S3 Unit #1 — Sedan & Basketball Accuracy Test (S3-1#-轿车-蓝球)
  • S3 Unit #1 — Road Bike & Mountain Bike Accuracy Test (S3-1#-自行车-山地车)
  • S3 Unit #2 — Sedan & Basketball Accuracy Test (S3-2#-轿车-蓝球)
  • S3 Unit #3 — Sedan & Basketball Accuracy Test (S3-3#-轿车-蓝球)
  • S3 Unit #3 — Road Bike & Mountain Bike Accuracy Test (S3-3#-自行车-山地车)