My Friendship with an R75

By Joseph C. Dille
USCA #2054

1971 R75/5 with Califonia Friendship Sidecar

Rear 3/4 view of R75/5 with Friendship Sidecar
My rig was a 1971 BMW R75/5 with a 1982 California Friendship sidecar. My reason for buying a BMW was their uniqueness and the reputation for reliability. My reason for wanting a sidecar was the same as many people, the need to carry a companion. In my case the companion is Bulk, a 70 pound black Labrador retriever.

The bike was (ab)used when I purchased it in November 1981. The previous owners had put no less than three coats of paint on it, the last coat must have been applied with a brush and touched up with a mop. All of the spokes were rusty, in fact corrosion seemed to cover the whole bike. However the price was right and it looked like it was going to be a long cold winter ahead. After taking my new purchase home I tried to gather all the information I could on improving the performance and reliability of the bike.

My first and probably best move was to become a member of the BMW Motorcycle Owners of America. They publish a very useful news letter, which provided me with all sorts of useful information. Each issue was filled with helpful hints about servicing the bike and BMW specific advertising. The next thing clever thing I did was to become a member of the USCA. The SIDECARIST was a fountain of facts, especially for someone who knew nothing about sidecars. To this day I look forward to receiving both publications.

The first modification I made to the bike was to install dual plugs and an electronic ignition. As a newly graduated mechanical engineer and a former aircraft mechanic I knew that adding a second plug would both boost performance and improve knock resistance on pump gas. The BMW combustion chamber benefits quite a bit from this modification since it is hemispherical with the original spark plug located way over to one side.

During my initial test ride of the bike I was dismayed by the way the transmission shifted. I was sure that BMW subcontracted its transmission work out to John Deer. The engine was also slow revving and the torque effect was pronounced. When I dissembled the engine I found the culprit. It seemed that the stock flywheel was fabricated by drilling some mounting holes in a sewer cover. This prompted me to give the flywheel to a machinist friend to have him surgically remove some metal.

Both modifications worked quite well. Shifting was markedly improved and the dual plugs improved the performance. I had a unique chance to do back to back testing of the before and after results of my work since my dad owned the same bike but unmodified.

Details of the restoration

Note: Most of this work was performed in my one room efficiency appartment. At one time I had the entire bike in the room with me. All assembly work was done on the gravel driveway.

I chose the California Sidecar Friendship model because it was lightweight, good looking and relatively low cost. Although it was not available when I made my purchase I recommend the USCA sidecar catalogue to anyone who is deciding which type of sidecar to buy. When I ordered the sidecar from the factory I managed to talk them into supplying the sidecar with a wire wheel instead of the standard mag-type wheel.

The sidecar arrived on a snowy spring day in a big, big truck. In fact the truck was so big that it did not have a chance to make it up mule trail that the land lord called a driveway. So for the next two hours I dragged the shipping crate up the hill to my apartment. Still breathless I opened up the crate like a kid with a new toy on Christmas and looked at all of the parts and read the few instructions that came with the unit.

Mounting the sidecar to the bike went well. The first step was ignoring the warning in the BMW manual that said that sidecars cannot be mounted to any BMW made after 1969. After much head scratching I figured I had enough pieces in the universal mounting kit to make a solid four point mount. I mounted one of the clamps as high as I could under the steering bearings. The second was just under the seat on the main frame. The third mount went in front of the engine on the right down tube. The fourth went as far back as I could get it on the lower part of the frame just behind the transmission. The last mount had a threaded rod that allowed both rails of the frame to be clamped so that they would both shared the load.

It took most of an early spring Saturday using trial and error to get all the mounts in position. It was already too dark for me to do a proper job of aligning the body on the frame and drilling the mounting holes. I decided at that moment that it was a perfect time to give myself my first sidecar driving lesson. So with the mounts in place and almost tight I set off with just the bare frame attached to the bike.

The first few laps in the gravel driveway went moderately well. I felt pretty confident as the weight of the bike leaned over onto the sidecar. Then reality suddenly set in as I started to make right hand turns. All I could think of was when I was 9 years old and the first time I rode an adult three wheel bike. My ride lasted about 15 seconds as I found out that counterstering was useless and I rode helplessly into the owners fence. Would history repeat itself? Only this time at highway speeds?

I was soon doing figure eights in the parking lot. My confidence was building as I tried to forget 10 years of two wheel motorcycle experience. I decided a good destination for my maiden voyage would be to Paul's house about 2 miles away on back roads. The trip over there went well. I cruised at 20 mph on the straights and about 10 mph for the left handers. The right handers were carefully negotiated at walking pace. Remember I did not have the weight of the sidecar body on the frame yet. When I arrived at Paul's house I found out that he had gone out. Disappointed I turned around and headed back home.

On the way back I started to get a little cocky. My speeds increased and I was going a little too fast around a gentle left hander when I hit a series of pot holes with the third wheel. As the wheel fell into the hole I felt like I was loosing my balance and I turned the bars to the right to keep from falling. This of course caused the sidecar wheel to come up and my partially completed rig to head off the road. The sidecar frame hit the dirt berm on the side of the road and the upper mount came off the bike and the others rotated causing the bike to fall over away from the sidecar. I learned two lessons:

1. Never ride with out the weight of the body on the sidecar.

2. Always tighten the mounting bolts all the way before riding.

There I sat on the side of the road looking over the damage and wondering how to get this mess back home. The sidecar frame was fine and the only damage to the bike was a little dent in the muffler. Luckily I had some tools so I finished removing the sidecar frame from the bike. I moved the frame over to the side of the road and placed it in a small snow bank. I rode the bike back solo and hopped into my car to retrieve the rest of my rig.

When I returned to the scene of the accident I could not see the sidecar. I looked and looked and I could not see any sign of the frame. I started to think was it this turn here or that one. These pot holes look like the ones but so do those. I was starting to think that it was all a bad dream when Paul and his wife came around the corner and saw me wandering around the side of the road.

I explained the situation and then all three of us started looking. Paul spotted a trail in the snow that went off into the woods. We walked back about 20 yards and found the frame just as I left it. It seems that someone had wanted the frame for himself and placed it back in the woods until they could return with a more suitable vehicle. We went back to Paul's house and had a beer and laughed at the whole situation.

After mounting the body on the frame I realized how pitiful the stock lighting was. Two round red lights with dual filaments that were wired together in the back and one stinky little marker in the front right side. The wiring harness was a complete joke with only two wires and a connector that did not lock together. I replaced the front marker light with a front turn signal from a 1968 Volkswagen. The new light matched the curves of the body and provided both the turn signal and marker light functions. I also replaced the outer rear light lens with a amber one so it could function as a turn signal and the other as a brake and marker light.

I used a 7 pin military type locking circular connector to electrically mate the bike to the sidecar. I added an extra 12V line to the cable to power the radio that I planned to install. I also routed the wires to both of the right side bike turn signals to this connector. For the rare occasion (Slow ride events and state inspections) that I ride solo I carried a extra plug that fitted into the bike side connector that would re-activate the right side turn signals. This system was very clean and worked well.

Pictures taken after the restoration

My first long trip was with Bulk to the 1982 USCA rally in Mercer Pennsylvania. I was pleased when Doug Bingham gave his approval to the solidness of my mounting job during the sidecar mounting and alignment clinic. The toe in and sidecar wheel lead was just right, but the bike was leaned in toward the sidecar about 2.5 degrees. Maybe this was the cause of my sore arms. All things considered Doug's evaluation was reassuring since the national rally was the first time I had ever seen a sidecar mounted to a bike close up.

At Doug's suggestion I leaned the bike out a little by taking one turn on the turn buckles. This made a great improvement in handling and my arms were less sore on the return from the rally. It took most of the summer to get over my solo bike instincts and as I did I leaned the bike out a little at a time until I had about 3 degrees of lean out. This happened at about a degree every other week. This process took me so long that my friend at work started to mark on his calendar every time I came in and said that I had finally gotten the alignment perfect.

Over the first summer I made three important changes to the bike. The first was mounting a steering damper from an old Volkswagen bug, the kind with a threaded end. I used a couple of muffler clamps along with the tie rod ends from a cub cadet garden tractor to make an appropriate mounting that would swivel with the steering. This helped keep the steering steady during acceleration in bumpy left hand corners. The second was the addition of a Metzeler block-K tire. This tire lasted almost twice as long as a regular motorcycle tire.

The last modification was adding a small subframe to help support the sidecar. The original mounting scheme worked well but I felt that the lower rear mount could have been located further back to give better triangulation and reduce the load on this mount. I acquired a used mount from an acquaintance at the National rally who got it with a sidecar that he planned to mount on a Moto Guzzi. I do not know who made this subframe. The sub frame mounted directly to the engine mounts and thus engaged the frame at the strongest point. The forward mount was roughly in the same place that I had it prior to the subframe but the rear mount was moved backward to just ahead of the passengers foot rest. The subframe stiffened the whole rig up especially during braking.

I owned the rig like this for about four years and 24 thousand enjoyable miles. I finally decided to sell my baby in order to move up to a bigger rig that could carry more and had better brakes. I sold the side car to a gentleman out on long island who eventually put it on an Amizonas motorcycle with a VW engine. The bike was restored to it's original configuration and is alive and well in up-state Pennsylvania. The block-K tire was sold very quickly to someone out in Oregon (I was still receiving calls about the tire 2 months after the add stopped).

In retrospect the whole experience worked out very well. I learned a lot about sidecars, sidecaring and the wonderful people involved in the sport. I had a roadworthy rig that carried Bulk, my wife and all of our stuff all over the east coast. In the end I got most of the money that I had invested back.

The 1971 R75/5 on a trailer heading off to its new owner. Sniff.

P.S. The bigger rig with good brakes is a 1986 BMW K100 with an EML GT, Bulk and I love it.

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