The Garage

Motocross

Stock-size parts in stock at MotoSport

KTM 450 SX-F 2026

Motocross, 449.9cc 4T, US version

Verified

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

From the owner’s manual: engine oil capacity 1.20 l, p. 150; coolant 0.95 l, p. 150; front tire 80/100-21 51M TT, p. 151; rear tire 110/90-19 62M TT, p. 151. Checked 16 Oct 2026.

No CPSC recall found for the 2026 KTM 450 SX-F, checked 2026-10-15. Recalls

KTM 450 SX-F 2026

Workshop card from motoxsports.com/bikes/ktm-450-sx-f-2026/ · each figure as the maker’s document prints it, with its source number; ≈ marks a figure we converted. Torque values are not published: use the manual.

Gearing

4 of 5 filled

Stock front sprocket
13T
Verified, read off the manual page: Manual p. 151 · checked 2026-10-14 source [1]
Stock rear sprocket
51T
Verified, read off the manual page: Manual p. 151 · checked 2026-10-14 source [1]
Chain pitch
520
Calculated, not printed: The trade name of the printed size 5/8 x 1/4" · Manual p. 151 · checked 2026-10-14 source [1]
Stock chain links
Not yet verified
Stock final drive ratio
3.92 : 1
Calculated, not printed: Calculated from the stock sprockets, printed on manual p. 151

Wheels and tires

2 of 4 filled

Front rim
Not yet verified
Rear rim
Not yet verified
Front tire
80/100-21 51M TT
Verified, read off the manual page: Manual p. 151 · checked 2026-10-14 source [1]
Rear tire
110/90-19 62M TT
Verified, read off the manual page: Manual p. 151 · checked 2026-10-14 source [1]

Suspension

3 of 7 filled

Fork
WP XACT AER
Verified, read off the manual page: Manual p. 150 · checked 2026-10-14 source [1]
Fork travel
310 mm (12.20 in)
Verified, read off the manual page: Manual p. 150 · checked 2026-10-14 source [1]
Shock travel
300 mm (11.81 in)
Verified, read off the manual page: Manual p. 150 · checked 2026-10-14 source [1]
Stock fork spring rate
Not yet verified
Stock shock spring rate
Not yet verified
Static sag, bike only
Not yet verified
Race sag, rider on
Not yet verified

Fluids and capacities

4 of 4 filled

Engine oil spec
10W/50 fully synthetic
Verified, read off the manual page: Manual p. 150 · checked 2026-10-14 source [1]
Engine oil capacity (capacities - engine: engine oil)
1.20 l (≈ 40.6 fl oz, converted by MotoXSports)
Verified, read off the manual page: Manual p. 150 · checked 2026-10-14 source [1]
Coolant capacity
0.95 l (≈ 32.1 fl oz, converted by MotoXSports)
Verified, read off the manual page: Manual p. 150 · checked 2026-10-14 source [1]
Fuel capacity
7.2 l (≈ 1.90 gal, converted by MotoXSports)
Verified, read off the manual page: Manual p. 152 · checked 2026-10-14 source [1]

Service specs

6 of 6 filled

Fork oil
Fork oil (48601166S1) (SAE 4): right outer assembly 240 ml (8.12 fl. ozUS); left outer assembly 240 ml (8.12 fl. ozUS); right cartridge 380 ml (12.85 fl. ozUS)
Verified, read off the manual page: Manual p. 154 · checked 2026-10-16 source [1]
Brake fluid
DOT 4 / DOT 5.1
Verified, read off the manual page: Manual p. 100 · checked 2026-10-16 source [1]
Coolant type
Coolant; antifreeze protection to at least: −25 °C (−13.0 °F)
Verified, read off the manual page: Manual p. 150 · checked 2026-10-16 source [1]
Fuel octane
Super unleaded (ROZ 95)
Verified, read off the manual page: Manual p. 152 · checked 2026-10-16 source [1]
Idle speed
2,200 rpm … 2,300 rpm (36.67 Hz … 38.33 Hz)
Verified, read off the manual page: Manual p. 149 · checked 2026-10-16 source [1]
Valve clearance
Intake at: 20 °C (68.0 °F) 0.10 mm … 0.15 mm (0.0039 in … 0.0059 in); Exhaust at: 20 °C (68.0 °F) 0.12 mm … 0.17 mm (0.0047 in … 0.0067 in)
Verified, read off the manual page: Manual p. 149 · checked 2026-10-16 source [1]

Maintenance

3 of 3 filled

Tire pressure (off-road)
1.0 bar (14.5 psi) front and rear
Verified, read off the manual page: Manual p. 151 · checked 2026-10-14 source [1]
Chain slack
58 mm … 61 mm (2.28 in … 2.40 in)
Verified, read off the manual page: Manual p. 88 · checked 2026-10-14 source [1]
Spark plug and gap
NGK LMAR9AI-10, gap 1.0 mm (0.039 in)
Verified, read off the manual page: Manual p. 150 · checked 2026-10-14 source [1]

Dimensions

3 of 3 filled

Seat height
958 mm (37.72 in)
Verified, read off the manual page: Manual p. 151 · checked 2026-10-14 source [1]
Wheelbase
1493 mm (≈ 58.8 in, converted by MotoXSports)
Verified, read off the manual page: Manual p. 151 · checked 2026-10-14 source [1]
Weight (weight without fuel approx.)
103.2 kg (227.52 lb)
Verified, read off the manual page: Manual p. 151 · checked 2026-10-14 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 2026-10-16. Rows marked not yet verified are blank on purpose.

Buying parts

The stock sizes and specs this bike left the factory with, each with its source. Take them to any shop.

Retailer links below are affiliate links: we may earn a commission, at no cost to you, and it never changes the specs. Affiliate disclosure.

Chain
Chain pitch 520 Owner's manual p. 151520 chains at MotoSport520 master links at MotoSport
Sprockets
Stock front sprocket 13T Owner's manual p. 151Stock rear sprocket 51T Owner's manual p. 15113T front sprockets at MotoSport51T rear sprockets at MotoSport
Tires
Front tire 80/100-21 51M TT Owner's manual p. 151Rear tire 110/90-19 62M TT Owner's manual p. 151Front tires 80/100-21 at MotoSportTubes 80/100-21 at MotoSportRear tires 110/90-19 at MotoSportTubes 110/90-19 at MotoSport
Engine oil
Engine oil spec 10W/50 fully synthetic Owner's manual p. 150Engine oil capacity (capacities - engine: engine oil) 1200 ml (40.6 fl oz) Owner's manual p. 150Engine oil at MotoSport
Coolant
Coolant capacity 950 ml (32.1 fl oz) Owner's manual p. 150Coolant at MotoSport

In stock at MotoSport

Prices from MotoSport’s catalog of Oct 14, 2026; check today’s price before you buy.

Front tire, stock size 80/100-21

Rear tire, stock size 110/90-19

Engine oil, stock viscosity 10W-50

Matched on viscosity only. The manual prints: 10W/50 fully synthetic. Check the label for the rest.

Prices and stock from MotoSport's product catalog on Oct 14, 2026; they change, so check the price at MotoSport before you buy. Products are chosen by exact stock size, code or oil viscosity from the specs above, known brands first, then price. We have not tested them.

3 part specs not yet verified; see data coverage.

Tools for this bike

Compare with

Comparisons with other bikes use the newest model year on file: KTM 450 SX-F 2027.

Other model years

All 4 model years, 2024 to 2027, side by side

Gearing calculator

Gearing for this bike

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 8–16 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—
Ratio change—
A —
B —
Taller · more speed Shorter · more pull

—

Changing the rear sprocket changes the chain length too. The chain length calculator works it out from the chain you have now, with where the axle ends up.

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

What's missing

24 of 31 fields read off a manual page.

Not yet verified (7): chain links, front rim, rear rim, fork spring rate, shock spring rate, static sag, race sag.

See coverage for every bike

Sources

  1. 1
    KTM Owner's Manual 2026, 450 SX-F / 450 XC-F, item no. 3240236en, dated 28/07/2025 (KTM print-on-demand portal, file 26_3240236_en_BA.pdf, read from the portal's page preview)pp. 88, 100, 149, 150, 151, 152, 154Manual page, verified. Covers stock front sprocket, stock rear sprocket, chain pitch, front tire, rear tire, fork, fork travel, shock travel, engine oil spec, engine oil capacity (capacities - engine: engine oil), coolant capacity, fuel capacity, tire pressure (off-road), spark plug and gap, chain slack, seat height, wheelbase, weight (weight without fuel approx.), engine oil figure, as labelled, weight, as labelled, fork oil, brake fluid, coolant type, fuel octane, idle speed, valve clearance; checked 2026-10-16.

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.

Your manual prints something different? Report a value with the page it is on; every fix is listed in the corrections log.

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
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