Dedicated Subsystem WorkbenchPlatform Gen: 2017–2026

2021 Harley Davidson Street Glide (Milwaukee-Eight) Tire Sizes, Cold Pressures & Gearing Ratios

OEM tire sizes, front cold PSI (), rear cold PSI (), sprocket teeth count, final drive ratio, and chain pitch for 2021 Harley Davidson Street Glide (Milwaukee-Eight).

Gen 2017–2026

Factory Platform Compatibility: All workshop fluid capacities, maintenance milestones, torque specifications, and consumables on this specification sheet are factory-identical across model years 2017 through 2026.

Select Model Year:(Active: 2021)

2017 2018 2019 2020 2021 2022 2023 2024 2025 2026

Engine

1746cc

Drive

Chain

Cooling

Precision Air/Oil-Cooled

Tire Engineering & Multi-Scenario Pressure Matrix

ETRTO Validated

Inflation targets calibrated across operating modes, verified rim width ranges, and certified alternate sizes.

Shop Direct-Fit Tires

Multi-Scenario Inflation Pressures

Solo Street / CommutingCold Baseline

Front: 36 PSI

Rear: 40 PSI

Two-Up Passenger & LuggageMax Load

Front: 38 PSI

Rear: 42 PSI

Off-Highway / Terrain Pressure

Maintain OEM cold baseline for street transfers; adjust -2 to -4 PSI for loose terrain.

Rim Geometry & ETRTO Envelopes

Front Wheel

OEM Rim Width:3.50"

Permissible Envelope:3.50" - 3.75"

Rear Wheel

OEM Rim Width:5.50"

Permissible Envelope:5.50" - 6.00"

Operating outside ETRTO envelope width alters crown radius, accelerates shoulder wear, and impacts lean stability.

Factory Dimensions & Verified Alternates

Factory Standard Sizes

Front:130/60B19

Rear:180/55B18

Verified Alternate Fitments

Factory Standard

Alternate profiles verified for swingarm, chain guard, and fender clearances.

Final Drive Gearing & Speed/RPM Calculator

Belt Drive

Factory reduction ratios, interactive sprocket gearing simulator, 6th gear cruising RPM matrix, and swingarm chain adjustment tolerances.

Shop Drive Belts

Drive Architecture

Poly-Chain Carbon Belt

OEM Pulleys

32T Transmission / 68T Wheel

OEM Final Ratio

2.125 : 1

Belt Teeth & Width

140T • 1.000 in (25.4 mm) Carbon Core

Cold Tension Deflection

3/8 - 1/2 in (9.5 - 12.7 mm) deflection with 10 lbs force

Quick Gearing Presets

Front Transmission PulleyStock: 32T

32 Teeth

Factory teeth count

Rear Wheel Belt PulleyStock: 68T

68 Teeth

Factory teeth count

Drive Ratio & Torque Impact

Calculated Final RatioStock: 2.125

2.125 : 1

Drivetrain Torque Delta

OEM Factory Baseline Dynamics

Balanced all-around factory engineering calibrated for EPA emissions and street usability.

Countershaft Speedo Variance:0.0%

Speedometer reads true to factory calibration standards.

Cruising Engine RPM in 6th Gear

60 MPH

Stock: 2,248 RPM

2,248 RPM

70 MPH

Stock: 2,623 RPM

2,623 RPM

80 MPH

Stock: 2,997 RPM

2,997 RPM

Calculated using factory 6th gear ratio (1), primary reduction (1.353), and 180/55B18 rolling circumference.

Belt Tension & Deflection Spec

Cold Deflection Tolerance

3/8 - 1/2 in (9.5 - 12.7 mm) deflection with 10 lbs force

Check tension using a 10-lb belt tension gauge at the lower belt run midpoint window on the side stand.

Belt Architecture

140T • 1.000 in (25.4 mm) Carbon Core

Inspect poly-chain carbon teeth for stone cuts and check tension on side stand cold

Recommended Belt: Gates Poly Chain Carbon Drive Belt

Shop Belt Tension Gauges Find Direct-Fit Gearing Sets

Factory Chassis Geometry

Chassis Alignment, Drive Tension & Rear Axle Calibration

Precision workshop alignment tools, dynamic drive tension tolerances, and axle spindle calibration for the 2021 Harley Davidson Street Glide (Milwaukee-Eight).

Belt Drive Architecture

Secondary Belt Deflection & 10-lb Tension Calibration

FACTORY BELT DEFLECTION SPEC:

3/8 - 1/2 in (9.5 - 12.7 mm) deflection with 10 lbs force

Measure cold deflection with a spring-loaded belt tension tool applying exactly 10 lbs (4.5 kg) of upward force at the lower belt run inspection window on jiffy stand.

CARBON BELT TOOTH & FLANGE INSPECTION:

140T • 1.000 in (25.4 mm) Carbon Core

Inspect polyurethane cog teeth for stone gouges or embedded gravel. Verify rear pulley chrome flanges show even belt tracking without edge fraying.

Official NHTSA Safety Recalls & Technical Bulletins

0 Open Campaigns (Clean)

U.S. Department of Transportation compliance database (Title 49 U.S.C. Chapter 301).

Verify VIN on NHTSA.gov

No Active Federal Safety Recalls Reported

The U.S. DOT National Highway Traffic Safety Administration (NHTSA) records zero open safety recall campaigns for the 2021 Harley Davidson Street Glide (Milwaukee-Eight) platform. Always check your individual 17-digit VIN at an authorized dealership or via NHTSA.gov for individual recall completions.