BMW R 18 B Bagger (K35) — OEM Fluid, Tire Pressure & Maintenance Specs
1,802cc Air/Oil-Cooled Big Boxer Twin OHV Pushrod 8-Valve · Source: BMW R 18 B Bagger (K35) (2021–Present) Official Owner’s Manual Maintenance Specifications
According to the BMW R 18 B Bagger (K35) (2021–Present) Official Owner’s Manual Maintenance Specifications, the 2021–Present BMW R 18 B Bagger (K35) (chassis K35/0L31) requires 3.6 L (3.80 US qt) of SAE 15W-50 (JASO MA2, API SJ / BMW Advantec Pro 15W-50) engine oil for a drain-only change and 4 L (4.23 US qt) with filter service (11427673541 / HF164). Standard solo cold tire pressure is 290 kPa / 2.90 bar / 42 PSI front (120/70 R19) and 320 kPa / 3.20 bar / 46 PSI rear (180/65 B16), paired with 2× NGK MAR8AI-10DS spark plug(s) and a BMW 26Ah AGM battery.
Drain only: 3.6 L (3.80 US qt)
R 320 kPa (3.20 bar)
Est. Range: ~413 km (257 mi)
1. Engine Lubrication, Filter & Clutch Specifications
| Clutch Architecture | Dry Single-Plate Manual Clutch (Separate Gearbox Oil) |
|---|---|
| Recommended Viscosity & Grade | SAE 15W-50 (Alt: SAE 20W-50) · JASO MA2 · API SJ / BMW Advantec Pro 15W-50 |
| Oil Volume (Drain / With Filter / Overhaul) |
• Drain only: 3.6 L (3.80 US qt) • With filter/strainer: 4 L (4.23 US qt) • Complete dry overhaul: 4.5 L (4.76 US qt) |
| OEM Oil Filter Code & Type | 11427673541 / HF164 |
| Correct Oil Level Check Method | Hold bike upright on level ground 3–5 min after warm shutdown; read crankcase sight glass |
| Oil Drain Bolt Torque | 32 N·m (23.6 lb-ft / 3.26 kgf·m) — Use fresh crush washer |
| Separate Transmission / Gearbox Oil | 1100 ml (1.10 L) — SAE 75W-90 GL-5 (800 ml separate manual gearbox) |
| Final Drive / Bevel Gear Oil | 200 ml (0.20 L) — SAE 75W-90 Hypoid Axle Oil (180 ml Paralever bevel drive) |
2. Cold Tire Pressures, Wheels, Ignition & Drivetrain
| Front / Rear OEM Tire Sizes | Front: 120/70 R19 · Rear: 180/65 B16 (Tubeless) |
|---|---|
| Cold Tire Pressure — Solo Riding |
Front: 290 kPa / 2.90 bar / 42 PSI Rear: 320 kPa / 3.20 bar / 46 PSI |
| Cold Tire Pressure — 2-Up / Loaded Touring |
Front: 290 kPa / 2.90 bar / 42 PSI Rear: 320 kPa / 3.20 bar / 46 PSI |
| OEM Spark Plug & Quantity | NGK MAR8AI-10DS × 2 (Gap: 0.8 mm) |
| OEM Battery Code & Rating | BMW 26Ah AGM (12V 26.0Ah Heavy-Duty AGM) |
| Final Drive Maintenance | Cardan Shaft Final Drive — Replace rear bevel-gear hypoid oil at exact measured volume |
| Brake Fluid & Coolant | DOT 4 · Air/Oil-Cooled Engine (No liquid coolant) |
3. Ergonomics, Range & Scheduled Service Intervals
| Displacement · Max Power · Peak Torque | 1802 cc · 91 hp @ 4,750 rpm · 158 N·m (116.5 lb-ft) @ 3,000 rpm |
|---|---|
| Seat Height & Wet Curb Weight | 720 mm (28.3 in) · 398 kg (877 lbs) |
| Fuel Tank & Est. Real-World Range | 24 L (6.3 US gal) · ~17.2 km/L → ~413 km (257 mi) |
| OEM Scheduled Maintenance Intervals |
• First Break-In: 1,000 km • Engine Oil / Filter: 10,000 km / 10,000 km • Air Filter / Spark Plug: 20,000 km / 20,000 km • Valve Clearance Check: 10,000 km |
4. Generation Cutoffs & Real-World Wrenching Gotchas
Model-Year & Chassis Generation Notes
Fork-mounted batwing K35 bagger equipped with a 10.25-inch TFT cockpit, Marshall audio, 24 L tank, ACC radar option, and automatic rear load-leveling suspension.
Oil & Clutch Mechanical Engineering Note
The massive 1,802cc OHV Big Boxer runs a dry single-plate anti-hopping clutch with 4.0 L of SAE 15W-50 engine oil, 1,100 ml gearbox oil, and 200 ml rear bevel oil.
Garage Wrenching Gotchas
- Its exposed nickel-plated open driveshaft is a centerpiece—wipe road grime off the universal joint area regularly and inspect for weeping pinion seals.
- Twin-cam OHV pushrods allow straightforward screw-and-locknut valve adjustments every 10,000 km; verify the electric Reverse Assist control-unit recall status.
5. Frequently Asked Questions (FAQ)
How are engine and separate drivetrain fluid capacities split on the BMW R 18 B Bagger (K35)?
The engine sump takes 3.6 L drain-only and 4 L (4.23 US qt) with filter (11427673541 / HF164) of SAE 15W-50 (JASO MA2), while isolated drivetrain cavities (separate gearbox 1100 ml, final drive 200 ml) require dedicated gear/chaincase fluid.
How do you accurately check the oil level on the R 18 B Bagger (K35), and what are its service intervals?
Hold the motorcycle dead-vertical on level ground 2–3 minutes after warm shutdown and verify the oil sits mid-way between the Upper and Lower marks in the crankcase sight glass—never on the sidestand. Torque the drain plug to 32 N·m with a new crush washer. Factory oil change intervals are every 10,000 km, with valve clearance inspection every 10,000 km.
What are the cold tire pressures, puncture repair type, seat height, and range of the R 18 B Bagger (K35)?
Fitted with 120/70 R19 front and 180/65 B16 rear tubeless rims (compatible with roadside plug kits), set cold tire pressures to 42 / 46 PSI (290/320 kPa) solo or 42 / 46 PSI loaded. Seat height is 720 mm (28.3 in) at 398 kg wet weight, delivering ~413 km per 24 L tank.