Vech's 1951 BMW R51/3 Motorcycle
And LS200 Steib Sidecar

This photo of my 1951 R51/3 & original Steib LS200 sidecar rig was taken at the 1997 BMW MOA National Rally in Fredricksburg, Texas.

I've ridden it to three national rallies. Every time, I won an award for "oldest BMW ridden."

seat      On Christmas, 1998, Elaine gave me this brand new red Steib seat, arm rests and windshield. These new parts really changed the look of the outfit. (Red side panels are missing.)

Manufactured between 1951 and 1954, the R51/3 was the third version of the 500cc R51. The loop-frame design, forks, wheels and tank looked the same, but the R51/3 engine and transmission were new. Parts from a R51/2 engine will not fit the R51/3 engine. The twin camshaft arrangement and the coil ignition of the R51/2 was replaced on the R51/3 with a single gear-driver cam and a magneto.

Sidecar outift with bear The R51/3 is an ideal machine if you want a plunger frame, telescopic fork pre-1955 BMW. The styling is streamlined with a exotic "bell" front fender. You can recognize a R51/3 by inspecting the iron cylinder fins, which have a rounded profile and six fins.

The R51/2 front fenders had stripes almost on the edge of the fender while the R51/3 had stripes set back from the edge by 3 and 1/16th inch on the sides and on the bottom of the bell front.

The sectional steel crankshaft with carefully balanced counterweights ensures vibrationless operation. It runs on hardened journals in two strong ball bearings. The hardened connecting rods run on roller bearings. They are generously lubricated by two oil splash rings on the crankshaft. The piston, piston pin, cams, push rods, rocker arms and valves are also splash-lubricated. The 1951 owner’s manual recommends that after every 6,000 miles, dismount the oil sump, remove the fine oil strainer in the bottom of the crank case and wash it thoroughly in gasoline. (See oil slingers.) Hella spot light mirror
Hella spotlight mirror

Steib and bear      type engine: four stroke, inclined, with overhead valves
2 cylinders, opposed type
carburetor: 2 Bing inclined type
magneto ignition, 6 volt dynamo
weight: 418 pounds
maximum permissible load: 781 pounds
engine oil capacity: approximately two quarts
maximum speed solo: 75 to 80 mph
maximum speed with sidecar: 56 to 60 mph
bore 68mm = 2.68 inches
stroke 68mm = 2.68 inches
piston displacement: 490cc
compression ratio: 1:6.3
24 horsepower
5,800 rpm
18,420 manufactured
wheels 19 inch, 3.50 X 19 tires

Engine numbers:
1951 R51/3 engine numbers began with 522 001 and ended with 526 209
1952 R51/3 engine numbers began with 526 210 and ended with 536 000
1953-1954 R51/3 engine numbers began with 536 001 and ended with 540 950

Frames after serial number 530 230 of the R51/3 had the sidecar frame hole bored to 13mm to accept a new, thicker bolt. Dealers were warned to not use the older, smaller bolt on new frames and that they should bore out the hole of older frames to accept the larger bolt.

BMW R51/3 hand shift, fishtail mufflers      R51/3s with serial numbers from 529380 forward should have been fitted with rubber fork boots. The R51/3 had 68mm bore, slightly domed five-ring pistons. Piston failure usually involved the skirt, a weak point in these machines.

Pre-1955 BMW motorcycles had an auxiliary hand-shift lever attached to the right side. It was useful primarily as a neutral finder. They had a beautiful chrome-plated, exposed drive shaft located on the right side of the frame. After 1951, all transmissions had a neutral light switch incorporated in the mechanism and connected to a green indicator bulb in the headlight shell. The single dry clutch plate design was actuated by cable and levers.

The R51/3 had fishtail mufflers on which the fishtails were of unequal length, with the lower one being longer. They were nice to look at, but the lower fin gained a reputation as an "ankle biter." By mid-1951, the lower fin was trimmed back to resemble the upper fin, both for reasons of aesthetics and as a safety improvement.

My LS200 is a Steib original, but Steib produces excellent reproduction sidecars and the reproduction parts fit all original Steib sidecars. I'm a sidecar set-up specialist and a dealer for Steib stidecars and parts. Check out The Steib Sidecar Store.

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