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1929 BMW R 11 Overview
For 1929, BMW offers the R 11 as an all-round motorcycle with 745 cc on tap. The 1929 BMW R 11 is built around a Side-Valve Flat Twin engine running Side Valve (SV) valve actuation, a compression ratio of 5.5:1. Internally, bore and stroke are 78 x 78 mm. Out on the road, the R 11 delivers 13.4 kW @ 4400 rpm) of peak power. In everyday use, the 1929 R 11 tips the scales at 182 kg and carries a 14 L fuel tank. That's roughly 7 kg lighter than the average all-round motorcycle in our database. Every technical detail, from suspension travel to tyre sizes, is covered in the full 1929 BMW R 11 spec sheet below.
1929 BMW R 11 compared with other bikes in the All-Round category
Measured against other bikes in the All-Round category in our database (up to 497 models, one entry per model), the 1929 BMW R 11 comes out as follows.
- With 74 W/kg, the R 11 has the 21st lowest power-to-weight ratio of 136 bikes in the All-Round category, 54% below the category average of 161 W/kg.
- Power output of 13.4 kW is lower than that of 108 of the other 145 bikes in the All-Round category.
- Only 162 of the other 496 bikes in the All-Round category have a larger engine displacement than the 745 cc of the R 11.
- Narrowing the field to the 11 models within five model years of it, the power-to-weight ratio of 74 W/kg is lower than that of 7 of the other 10.
1929 R 11 - Pros & Cons
Strengths
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Capable power output: 13.4 kW @ 4400 rpm) of peak output puts the R 11 in good company among its rivals.
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Low-maintenance final drive: Shaft final drive is about as close to maintenance-free as motorcycle drivetrains get.
Considerations
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Carburetor fuelling: Carburetion is more hands-on than fuel injection - plan on periodic jetting and cleaning as part of routine ownership.
Wear Points & Servicing Notes
Heat management in traffic
Air cooling on the R 11 keeps the mechanical layout simple, but heat management in slow traffic needs more attention than on a liquid-cooled bike - plan routes and gear accordingly in warmer conditions.
Carburetor maintenance
Being carbureted, the R 11 is more sensitive to stale fuel and altitude changes than a fuel-injected bike - a carb clean and rejet restores crisp throttle response after any extended lay-up.
Suspension condition on used examples
Suspension duties are handled by Plate spring 9 laminae up front and Rigid, spring loaded saddle at the rear. Weeping fork seals aren't a dealbreaker on a used bike, but they're a fair basis for negotiating price.
Final drive maintenance
Shaft final drive on the R 11 removes chain and belt maintenance entirely - the trade-off is a little extra unsprung weight and periodic gear-oil changes.
Frame & chassis check
The Twin loop pressed steel frame chassis holds up well with normal use; on a used bike it's still worth checking the head-stock and swingarm pivot area for impact damage or corrosion.
R 11 - Buying & Maintenance Guide
What to check before buying
A pre-purchase check on the 1929 BMW R 11 with its 745 cc all-round should cover the same ground every time: service history, drivetrain condition, and any oil seepage around the casings. This model runs shaft final drive, so ask for proof the shaft-drive gear oil has been changed on schedule - it's easy to overlook since there's no chain to draw attention to it. Now 97 years old, this all-round is as likely to show age-related wear (perished rubber, seized fasteners, degraded seals) as mileage-related wear. Start it from cold if you can - a well-kept R 11 settles to a smooth idle within seconds.
Oil and filter changes
Oil changes are the cheapest insurance you can buy for the R 11's 745 cc side-valve flat twin - keep to the manufacturer's interval rather than stretching it. With a 5.5:1 compression ratio, running the octane grade specified in the manual matters more than on a lower-compression engine. Use the viscosity grade the manual specifies, not whatever's on sale.
Carburetor upkeep
An R 11 that's sat unused is almost always a carb-cleaning job before it runs right again - float bowls and pilot jets first, since they clog before anything else.
1929 BMW R 11 - Frequently Asked Questions
What engine does the 1929 BMW R 11 have?
The 1929 BMW R 11 uses a Side-Valve Flat Twin engine with 745 cc of displacement. It is air cooled.
How much does the 1929 BMW R 11 weigh?
The 1929 BMW R 11 weighs 182 kg. This is the manufacturer's wet figure.
How much power does the 1929 BMW R 11 make?
The 1929 BMW R 11 produces 13.4 kW @ 4400 rpm) of power.
What is the fuel tank capacity of the 1929 BMW R 11?
The 1929 BMW R 11 has a 14 L fuel tank. At around 5-6 litres per 100 km, that is roughly 233-280 km between stops.
What brakes does the 1929 BMW R 11 have?
The 1929 BMW R 11 uses Ø200mm Drum at the front and Ø37mm Cardan brake at the rear.
What gearbox does the 1929 BMW R 11 have?
The 1929 BMW R 11 is fitted with a 3 Speed transmission.
What fuel system does the 1929 BMW R 11 use?
The 1929 BMW R 11 uses Single carburetor type BMW Ø24 mm (1933: 1 x carburetor type Amal 6/406 SP and 6/407 SP), providing precise fuelling across the rev range and reliable cold-start behaviour.
Key Specifications
Engine
Side-Valve Flat Twin
Power
13.4 kW / 18hp @ 3400 rpm ( 1933: 14.9 kW / 20hp @ 4400 rpm)
Fuel Capacity
14 L / 3.7 US gal
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Full 1929 BMW R 11 Specifications
Year
1929-34
Make
BMW
Model
R 11
Make Model
BMW R 11
Fuel Capacity
14 L / 3.7 US gal
Wet Weight
182 kg / 401 lbs
Bore x Stroke (mm)
78.0 x 78.0 mm
Bore x Stroke (in,)
3.07 x 3.07 in
Stroke
78.0 mm
Displacement (cc)
745 cc
Displacement (ci)
45.5 cu-in
Engine Type
Side-Valve Flat Twin
Fuel Control
Side Valve (SV)
Displacement
745 cc / 45.5 cu in.
Engine Detail
Four stroke, two cylinder flat twin, Side valve
Bore x Stroke
78 x 78 mm
Compression Ratio
5.5:1
Cooling System
Air cooled
Fuel Induction
Single carburetor type BMW Ø24 mm (1933: 1 x carburetor type Amal 6/406 SP and 6/407 SP)
Ignition
Magneto
Starter
Kick
Clutch
Single plate dry clutch
Final Drive
Shaft
Gear Ratios
1st 2.83 / 2nd 1.55 / 3rd 1.08:1
Transmission / Drive
3 Speed
Frame Type
Twin loop pressed steel frame
Suspension - Front
Plate spring 9 laminae
Suspension - Rear
Rigid, spring loaded saddle
Charging System
Bosch Magneto generator D2L or Magneto Ignition FF2
Brakes - Front Diameter (mm)
200 mm
Brakes - Front Diameter (in.)
7.9 in
Brakes - Rear Diameter (mm)
200 mm
Brakes - Rear Diameter (in.)
7.9 in
Brakes - Front
Ø200mm Drum
Brakes - Rear
Ø37mm Cardan brake
Specifications are compiled from manufacturer documentation and cross-referenced
technical sources, and corrected on an ongoing basis.
Spot an error? Let us know.
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