"Motor Cycle" magazine BMW R51/2 road test-November 30, 1950
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Vech and I have had the BMW R51/2 sitting around Bench Mark Works since January, 1999, when we had it sandblasted and stored in several cardboard boxes. BMW reproduces an English version of the R51/2 owner manual and parts manual, but the shop manual exists only in German (which we can't read). We bought a shop manual just to look at the drawings, which aren't very extensive. Vech didn't seem concerned about the fact he can't read the shop manual, even though he had never restored a R51/2 before planning this restoration. He keeps saying, "Don't worry, baby. I'll figure it out." I believe him. |
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During September, 2001, Vech and I began pulling parts, sending parts
out to be chromed, sorting parts and getting ready to assemble the
bike. I sanded the frame. Vech primed the frame. I sanded the frame.
Vech painted the frame. I sanded the frame. Vech painted the frame.
Shooo! The frame is glossy black and ready for assembly. Does anyone
wonder why I no longer use nail polish? I wrote BMW Mobile Traditions about the history of my R51/2, serial number 519 162, and learned that it was built September 12, 1950 and delivered to a dealer, "Juengst" in Heborn, Germany. We bought the R51/2 from someone in Canada. It is destined for a second birth at Bench Mark Works, Sturgis, Mississippi, United States of America. |
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I took the horn apart, bead blasted it and gave it to Vech. He cleaned the points. We taped the horn electrical parts to protect them. I primed the parts and they are ready to paint next time we run a batch of black paint. The screws on the outside rim of the horn are black, but the two tiny screws that hold the "Bosch" tag are chromed. I used a Caswell "copy-chrome kit" to replate those two screws. Once the horn is painted, it's just a matter of connecting the horn to a 6-volt battery charger for voltage and adjusting the screw on the back of the horn until the horn sounds like a horn (rather than a duck quack). |
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Vech couldn't get the rear spring out, so we cleaned it the best we could, taped it up and left it in place during bead-blasting. The cork of my favorite wine (Beringer white zinfandel) came in handy. The cork fits the final drive axle hole perfectly to protect the inside from bead blasting. Someone years ago, reamed out the threads of the oil plug to replace it with a Volkswagen lug bolt. We have to get that place welded so Vech can repair the threads to hold an original-type plug. |
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I
took the wheels apart. Vech installed new sealed wheel bearings. We
bead-blasted the hubs, primed them and painted them glossy black. As
for the spokes, Vech drilled eighty holes in four lengths of wood to
make a "eighty-spoke holder." It works great to hold spokes for
bead-blasting, priming and painting. We put the original rims in
storage. We are using
reproduction rims from BMW Mobile Traditions: 36 31 4 038 327--rim 19" black powder-coated with silver center 2.15x19-inch, half-hub R51/2-R68 |
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We cleaned and brushed the engine in the parts washer, bead-blasted it, and cleaned it well with carb cleaner. Vech was cleaning the bolt threads with a die when two pieces of the engine case came off into his hand. Vech can weld, but we use a welder named Andy Hodnett, who has figured out the exact aluminum alloy rods to use. He can weld that place back solid so Vech can tap it. |
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Brake shoes: I removed the front wheel lining by punching out the rivets and the lining fell right off. When it came to the rear brake lining, I was dismayed to learn that someone had glued-on the brake linings! It was a challenge to chisel-off the linings. Since those linings were probably asbestos, instead of a bench grinder, I used a file to get off the last bit of lining. Just when I thought we were ready to re-line the brake shoes, Vech noted that someone had drilled the holes much larger than standard. We asked Andy Hodnett to weld the holes back solid. Vech drilled the holes back to standard size and installed non-absestos lining with copper rivets. See the complete brake lining instructions. |
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