The Garage

Motocross

KTM 450 SX-F

Motocross, 450cc 4T, 2027, US version

Verified

Illustration: a KTM motocross bike, not this exact model.

Gearing

4 of 5 filled

Stock front sprocket
13T
Owner's manual p. 153, checked 2026-09-28 (source 1)
Stock rear sprocket
51T
Owner's manual p. 153, checked 2026-09-28 (source 1)
Chain pitch
520
Owner's manual p. 153, checked 2026-09-28 (source 1)
Stock chain links
Not yet verified
Stock final drive ratio
3.92 : 1
Calculated from the stock sprockets

Wheels and tires

2 of 4 filled

Front rim
Not yet verified
Rear rim
Not yet verified
Front tire
80/100-21 51M TT
Owner's manual p. 154, checked 2026-09-28 (source 1)
Rear tire
120/80-19 62M TT
Owner's manual p. 154, checked 2026-09-28 (source 1)

Suspension

6 of 7 filled

Fork
WP XACT AER (air fork)
Owner's manual p. 155, checked 2026-09-28 (source 1)
Fork travel
310 mm (12.2 in)
Owner's manual p. 152, checked 2026-09-28 (source 1)
Shock travel
300 mm (11.8 in)
Owner's manual p. 152, checked 2026-09-28 (source 1)
Stock fork spring rate
Not yet verified
Stock shock spring rate
45 N/mm
Owner's manual p. 158, checked 2026-09-28 (source 1)
Static sag, bike only
35 mm (1.4 in)
Owner's manual p. 158, checked 2026-09-28 (source 1)
Race sag, rider on
105 mm (4.1 in)
Owner's manual p. 158, checked 2026-09-28 (source 1)

Fluids and capacities

4 of 4 filled

Engine oil spec
SAE 10W/50 fully synthetic
Owner's manual p. 152, checked 2026-09-28 (source 1)
Engine oil capacity
1200 ml (40.6 fl oz)
Owner's manual p. 152, checked 2026-09-28 (source 1)
Coolant capacity
950 ml (32.1 fl oz)
Owner's manual p. 152, checked 2026-09-28 (source 1)
Fuel capacity
7.2 L (1.90 gal)
Owner's manual p. 154, checked 2026-09-28 (source 1)

Maintenance

3 of 3 filled

Tire pressure (off-road)
1.0 bar (14.5 psi) front and rear
Owner's manual p. 153, checked 2026-09-28 (source 1)
Chain slack
58-61 mm (2.28-2.40 in)
Owner's manual p. 89, checked 2026-09-28 (source 1)
Spark plug and gap
NGK LMAR9AI-10, gap 1.0 mm
Owner's manual p. 152, checked 2026-09-28 (source 1)

Dimensions

3 of 3 filled

Seat height
958 mm (37.7 in)
Owner's manual p. 153, checked 2026-09-28 (source 1)
Wheelbase
1493 mm (58.8 in)
Owner's manual p. 153, checked 2026-09-28 (source 1)
Weight
103.2 kg (228 lb)
Owner's manual p. 153, checked 2026-09-28 (source 1)
Solid marks are owner's-manual pages; hollow marks are manufacturer web or spec-sheet figures still waiting on a manual page. Last reviewed 2026-09-28. Rows marked not yet verified are blank on purpose.

What's missing

21 of 25 fields read off a manual page.

Not yet verified (4): chain links, front rim, rear rim, fork spring rate.

See coverage for every bike

Tools for this bike

Compare with

Buying parts

The stock sizes and specs this bike left the factory with, each with its source. Take them to any shop. Retailer links will appear here once a store approves MotoXSports.

Chain
Chain pitch 520 Owner's manual p. 153
Sprockets
Stock front sprocket 13T Owner's manual p. 153Stock rear sprocket 51T Owner's manual p. 153
Tires
Front tire 80/100-21 51M TT Owner's manual p. 154Rear tire 120/80-19 62M TT Owner's manual p. 154
Engine oil
Engine oil spec SAE 10W/50 fully synthetic Owner's manual p. 152Engine oil capacity 1200 ml (40.6 fl oz) Owner's manual p. 152
Coolant
Coolant capacity 950 ml (32.1 fl oz) Owner's manual p. 152
Suspension springs
Stock shock spring rate 45 N/mm Owner's manual p. 158

2 part specs not yet verified; see data coverage.

Garage tool 01

Sprocket calculator

Put your current gearing in Setup A and the setup you are considering in Setup B. Everything updates as you type.

Pick a bike to fill both setups with its stock sprockets.

Front sprockets 10–16 teeth, rear 34–60. Values outside that range are brought back to the nearest limit.

Setup A — what you run now
Setup B — what you are thinking about
Final drive ratio

— — : 1

—
Pull at the wheel—
Top speed—
Chain (est.)—
A —
B —
Taller · more speed Shorter · more pull

—

Ratios are exact. The chain figure is an estimate of roughly one link per two teeth of change — confirm against your manual before ordering.

Sources

  1. 1
    KTM Owner's Manual 2027 450 SX-F, Item no. 3240384en (06/08/2026); owner-supplied copy from the KTM Group print-on-demand portalpp. 89, 152, 153, 154, 155, 158Manual page, verified. Covers stock front sprocket, stock rear sprocket, chain pitch, front tire, rear tire, fork, fork travel, shock travel, stock shock spring rate, static sag, bike only, race sag, rider on, engine oil spec, engine oil capacity, coolant capacity, fuel capacity, tire pressure (off-road), chain slack, spark plug and gap, seat height, wheelbase, weight; checked 2026-09-28.

Always confirm against the manual for your exact year before ordering parts or setting up suspension. Torque specs are deliberately not published here. How we verify a value.

My settings

Date / track
Sprockets run
Race sag / free sag
Fork air pressure or spring
Fork clickers (compression / rebound)
Shock clickers (low / high / rebound)
Tire pressures (front / rear)
Notes
All bikes