Dedicated Subsystem WorkbenchPlatform Gen: 2009–2022

2018 Harley Davidson Iron 883 (Sportster) 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 2018 Harley Davidson Iron 883 (Sportster).

Gen 2009–2022

Factory Platform Compatibility: All workshop fluid capacities, maintenance milestones, torque specifications, and consumables on this specification sheet are factory-identical across model years 2009 through 2022.

Select Model Year:(Active: 2018)

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Engine

883cc

Drive

Chain

Cooling

Air-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: 30 PSI

Rear: 36 PSI

Two-Up Passenger & LuggageMax Load

Front: 32 PSI

Rear: 42 PSI

Trackday / Closed CourseTrack Calibrated

Front: 32 Cold / 34 Hot

Rear: 28 Cold / 30 Hot

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:100/90-19

Rear:150/80B16

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

29T Transmission / 68T Wheel

OEM Final Ratio

2.345 : 1

Belt Teeth & Width

136T • 1.125 in (28.6 mm)

Cold Tension Deflection

1/4 - 5/16 in (6.4 - 7.9 mm) deflection with 10 lbs force

Quick Gearing Presets

Front Transmission PulleyStock: 29T

29 Teeth

Factory teeth count

Rear Wheel Belt PulleyStock: 68T

68 Teeth

Factory teeth count

Drive Ratio & Torque Impact

Calculated Final RatioStock: 2.345

2.345 : 1-0.01%

Drivetrain Torque Delta

0.0% Taller Gearing (Reduced Highway RPM)

Lengthens transmission gears, lowers sustained engine RPM on motorways, and reduces engine buzz and vibration.

Countershaft Speedo Variance:+0.0%

At 70.0 mph indicated speed, true vehicle ground speed is 70.0 mph.

Cruising Engine RPM in 6th Gear

60 MPH

Stock: 3,137 RPM

3,137 RPM

70 MPH

Stock: 3,660 RPM

3,660 RPM

80 MPH

Stock: 4,183 RPM

4,182 RPM

-1 RPM

Calculated using factory 6th gear ratio (1), primary reduction (1.688), and 150/80B16 rolling circumference.

Belt Tension & Deflection Spec

Cold Deflection Tolerance

1/4 - 5/16 in (6.4 - 7.9 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

136T • 1.125 in (28.6 mm)

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 2018 Harley Davidson Iron 883 (Sportster).

Belt Drive Architecture

Secondary Belt Deflection & 10-lb Tension Calibration

FACTORY BELT DEFLECTION SPEC:

1/4 - 5/16 in (6.4 - 7.9 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:

136T • 1.125 in (28.6 mm)

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 2018 Harley Davidson Iron 883 (Sportster) platform. Always check your individual 17-digit VIN at an authorized dealership or via NHTSA.gov for individual recall completions.