Would you like to put a sidecar on your /2 and then be able to take it off and ride solo whenever you wanted to? Most of the following article was published in the January 1988 BMW Motorcycle Owners of America Owners News, pages 52-55, under the title of "Sidecaring the /2".
AQUISITION AND REPAIR
In the Spring of 1985 I saw an ad in the Louisville paper for an R69S in Bowling Green, about 100 miles away. I drove there and found the bike at Jimmy Allen's Used Cars, with a couple of other old BMWs for sale. I bought the R69S for $1,900 and made a few calls to put its history together. It had been taken in trade in 1984 by Four Seasons Cycle in Northern Ohio and sold to a man whose wife said he could not keep it, so he had left home for an extended late summer tour. He had travelled as far as Arizona before deciding to return home. In mid-November he was wending his way back to Ohio and stopped at a restaurant on I-65 in Bowling Green. He was was cold, broke, and knew he could not go home with the bike. Jimmy Allen saw the bike in the parking lot, drove in and made an offer that the owner was in no position to refuse.
The bike's speedometer showed kilometers for about 22,000 miles, and there was a little knock in the motor, which was attributed to the rear bearing. In November of 1985 I removed the motor and shipped it to C&D BMW in Freeport, IL for an overhaul. I bought new 1st oversize pistons, bearings and carbs (on sale for $75 each) from Capitol Cycle and sent the bearings on to C&D. C&D cleaned the oil slingers, replaced the bearings, bored the cylinders and did a valve job, all for about $400. I put the motor back together and it broke in just fine and ran perfectly.
URAL JUPITER SIDECAR
In 1986 I had just finished renovating the R69S when Minor Noe of New Albany, IN, offered to sell me his Jupiter sidecar for $700 and a set of almost new 26/6 gears for $200. My leap into sidecaring was spurred by a combination of factors that no doubt have to be present for anyone to make such a move. The sidecar was on another /2, so there would be the opportunity for a comparison drive and no attachment problems. The sidecar was close to home, so it could be conveniently visited and easily hauled home. The owner had the necessary gears at a good price, and an experienced dealer was available a few hours away who could install the gears. And not least, my wife Elsie was so taken by the sliding nose, the secure armrests and the soft ride that she offered to split the cost of the sidecar.
ADAPTING THE BIKE
So I decided to go into sidecaring with a way out. From what I had read and heard, the most difficult, costly and irreversible part of adapting a /2 for sidecar duty was changing the gears. It had to have the lower gearing, and changing the gears was a dealer job costing about $100 labor plus miscellaneous parts. So I opted to leave my stock rear end (marked 27/8 which equals 3.38) intact, and build up a separate rear end for sidecar use by having my newly acquired 26/6 (4.33) gears installed into a used housing. T&B BMW of Linton, Indiana had a used housing for $100 and installed the 26/6 gears into it with new bearings, shims and seals for $100 labor plus $100 parts. It was inexpensive and simple to obtain used brake shoes from a BMW News advertiser and reline them with a lining and rivet kit from Capitol Cycle. I now had two complete rear ends which could be changed in my garage in about 30 minutes.
Other initial modifications to the /2 at this time, consisted of installing new shocks and heavy duty springs from Capitol Cycle at about $250. I had seen a /2 rig bobbing wildly over a pot-holed dirt road ten years ago, and didn't like the looks of that. I made up a crude spring compressor for the front units, but later found that Ed Korn of Madison, WI makes a better one for about $35. The rear shock was frozen top and bottom, and had to be demolished to remove it. I reinstalled with anti-seize at the bottom, which was a mistake since the shock unscrewed itself there after a few hundred miles; it's best to install it bone dry.
Shock compressor made from plywood, coat hangers, and JC Whitney spring compressors.
SET UP AND TRIAL RUN
You can read in any sidecar manual or the owner's manual how to set up toe-in and lean-out to counteract the pull of the sidecar. Initially, about 1 inch of toe-in and a visible amount of lean-out should do; the best setting will depend on your sidecar and the load. I read in the owner's manual that in addition to re-gearing, the Earle's pivot should be adjusted to the front position and the hydraulic damper of the R69S should be replaced with the friction damper of the R50 and R60 models. The sidecar books had described how decreasing the trail (moving the Earle's pivot forward) served to reduce steering effort; steering effort was bound to be less than the effort of moving the pivot, so I didn't bother to do that. Nor did I have a friction damper to replace the little hydraulic damper that the R69S came with.
The sidecar was attached barely in time for a ride to introduce the rig to a rally of the local BMW Car Club of which I was secretary/editor, however that ride was never completed. Beginning at 15 mph a wobble commenced, so powerful that all my strength could not restrain the handlebars, and I dared not accelerate through the wobble to see if it would diminish at higher speed. Elsie, watching and feeling the oscillations from the sidecar seat, was appalled at what I had gotten us into, and insisted that we turn around after the first half mile.
From that date on, I began to think that the principles of sidecar theory and operation do not always transfer verbatim from the book to the bike; that each bike and sidecar combination are different from any other; and that new territory is best explored by trial and error. Needless to say, I immediately moved the Earles pivot, which almost eliminated the wobble, and drew the conclusion that reducing the trail had more to do with stabilizing the steering against the forces of the sidecar than with reducing steering effort.
In moving the Earles pivot bolt, it is important to dress both the bolt and the unthreaded hole, to eliminate what could be a very bad jam-fit. Use emery cloth to polish the machining marks and any pits or rust off of each shoulder of the bolt. Use a small brake cylinder hone in an electric drill to ream the paint out of the unthreaded holes (both front and back holes). Put anti-seize on everything, and keep trying until the bolt can be inserted to the threaded side with nothing more than a few gentle taps. If you don't do this, it could take all the persuasion of a framing hammer and a 24mm box end, and cause some damage to the bolt and the hole.
With the Earles pivot in the front position, the wobble went into hiding, so to speak. To explain this phrase, let me say that it seems all bolted-up sidecar rigs have an inherent tendency to wobble the forks under certain conditions. Success in setting up the rig is judged by the degree by which this tendency is suppressed. At this point, my rig would try to wobble on deceleration at 15 mph. Normal holding onto the handlebars would prevent it from the wobble; releasing the bars would allow it to grow into a tank-slapper. This mild tendency to wobble under certain circumstances is normal for most rigs, but I felt it was not quite right for an Earles BMW, and could be due to the lack of a strong damper. The new hydraulic damper on my R695 was smooth but far too weak for sidecar use.
While looking for a friction damper, I obtained a set of Metzeler Block K 4.OOxl8 tires from BMW Motorrad of St.Louis for about $150. On the rear, this tire's unusually large circumference compensated for the low 4.33 gearing, and raised the cruising speed by a few more welcome mph. On the front, the big flat contact patch further reduced the tendency to wobble.
MORE CHANGES
Over the next winter, I located and adapted an R27's friction damper and replaced the ball bearing steering races with tapered roller bearings from Ed Korn for $30. This all went hand in hand, as the fork must be removed to drill out the pressed-in stops for the hydraulic damper's plate: these stops are on the face of the surface needed by the friction plate. The tapered roller bearings have two advantages. They are caged so they just drop in as a unit (no chasing and counting little ball bearings), and they can take more loads than ball bearings, so they can be snugged down tighter and stand up better against sideways forces of sidecar steering. After the friction damper and roller bearings were installed, all tendencies to wobble vanished and could not be provoked to appear.
The 26/6 (4.33) gearing actually seemed too low for the light Jupiter sidecar, because high cruising speed sounded like about 60 mph. This speed was confirmed after the speedo was re-geared and renovated by North Hollywood Speedometer for about $70. Thinking the motor might be able to pull the Jupiter under ideal conditions with the stock 27/8 (3.38) gearing, I reinstalled the original rear end and took a ride with the windshield off the Jupiter and the tonneau cover on. I was not pleased with the results, even though I have since met an R69S owner who pulls a small Dreyer sidecar with stock gears. Starting off required excessive clutch slip, the motor strained to accelerate in each gear, and top speed was 65 mph in 4th with the throttle wide open and the motor unable to get up into smooth high rpm. Add a passenger and luggage, two windshields, a long Interstate grade, a headwind, and a hot summer's day-and there is potential for disaster. So back on went the 26/6 rear end.
URAL MILITARY SIDECAR
The next move was to trade up to a full sized Ural M-66 sidecar, a replica of the WW2 German military sidecar. The Jupiter was sprung too softly for good handling, and looked out of character with the /2 BMW. In retrospect, its soft ride and comfortable seat with armrests and handgrips were much better for the passenger than the Ural's crude seat and open-sided cockpit. But the Ural miliatary model was better looking, heavier, stiffer sprung with an easily replaceable BMW spring/shock, and the 26/6 gears seemed just right to pull it. With the addition of this larger sidecar, perfection seemed to be reached within the limits of the limited horsepower I had to work with.
To summarize, the outfit was a 250 lb. Ural on a 42 HP R695 with 26/6 gears, Metzeler Block K 4.00-18 tires front and rear, new shocks and HD springs, an Earles fork set to the sidecar position with the hydraulic damper changed to friction, and tapered roller bearings in the steering head. The outfit steered well, handled stable and flat, pulled easily from a stop when loaded and accelerated smartly, cruised at 55-60 mph, and was ideally geared for driving around town and on hilly 2-lane roads.
AVONAIRE FAIRING
For the third winter of ownership, I undertook the project of renovating an old Avonaire full fairing which I bought unseen from a parts dealer in Detroit for $200. The wind-shield turned out to be a home-made, flat plexiglass affair. The bracketry was mystifying without the instructions or hardware; and someone had sawed the dashboard out as if to better reach the key, which had broken the fairing's back. Stripping off all the spray-can paint and tape stripes, further revealed that the fairing had been down several times and repaired with putty.
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I considered reselling it as is, but doubted that I could get back what I had in it. Also I had by now learned that the fairing was still being made in England by the Sprint Mfg. Co, and was imported on special order by Street Cycles of Falmouth, ME for sale to dealers only, with a total installed price of around $900. With the incentive of saving some money, I obtained a carton of little glass mixing jars, suspended the Avonaire from pipes in the basement, and spent many evenings gradually repairing and reinforcing the fairing with fiberglass. The dash was filled with saturated cotton balls, and covered with cloth, healing the huge gash that had been cut in it. More layers of cloth were used to span cracks and weak spots in the sides and around the cylinder holes. Before painting, I mounted it on the bare bike and made holes in it through which to poke the sidecar struts. A professional paint and stripe job - and all new brackets, hardware and windshield from England - produced a fairing that was like new, only heavier and stronger, for a total investment of $600. The Avonaire is the most beautiful fairing ever made, to my eye. But was very difficult to get on and off the bike, as the exhaust system had to be removed, and one person had to support the front of fairing while another person spread the sides to slip them over the jugs. Fortunately there was a removable front panel that made access to the points and harmonic damper rubber easy. Unlike on my earlier R69US, I did not dare remove the damper because the bike needed top RPMs to pull the sidecar gearing.
Now with the /2 settled into its role as a sidecar puller, I was curious about the minimum effort it would take to ride it solo again-to set it up where it could reach distant rallies via Interstate at its designed cruising speed. I had tried it solo for five miles after dropping off the Jupiter sidecar at the new owner's place, and that was scary. Basically, it felt tippy at slow speeds, like first learning to ride a bicycle. I attributed this to the Earle's pivot positioning as much as the square-edged tires, and lamented that to change to solo would take a half-day's hard work changing the pivot position, the tires and the rear end housing. But at the Shakamak '87 Rally I heard someone say that the /2 could be ridden solo with the forks in the sidecar position, as new owners had done this for a long time without knowing the difference. Then I realized that the Block K tires could be the real obstacle to solo riding. I changed the 4.00 Block K on the front to an old 3.25 I had, and went for a spin with the sidecar. The leanout had increased; and after that was cor-rected, the only effect of the regular tire was to make it a lit-tle easier to induce a wobble. This seemed to prove once again that the huge ground patch of the Block K enables the Earles fork to transmit its special geometry to the pavement for full stabilizing effect.
The next step was to see how this tire helped a solo ride. The sidecar was quickly detached with aid of a home-made dolly, and a trip around the block in the solo mode was made. The solo ride felt pretty good-much better than before. The solo front tire, with its rounded profile, made all the difference. The solo ride was so good, and the rear Block K was so worn after only 2,000 miles, that it seemed a waste of money to put a regular tire on the rear for sidecar pulling. With the solo handling settled, off came the stump-puller 26/6 and on went the stock 28/8, and the high-speed tourer of the 60's rolled again. Now, I wouldn't want to corner too hard on that rear Block K, but it's good to know that with only about a half-hour's work, the workhorse sidecar puller can stretch its wings and reach those far-off rallies without stress.
Actually, I almost prefer to ride hitched. It is slower, safer, and more interesting. The rig won't go much over 70, as that is about red-line and rather twitchy with oversteer, and 45 is a very relaxed speed for the motor and gearing. Gravel or leaves on the road are an opportunity for a little squirreling rather than a danger, and cars give more respect when because they realize that you can tolerate a little fender bender without upset. The interest factor comes for the increased challenge of handling the rig. It is some-what like driving a tractor with an implement on the side. On a flat road you can ride hands off, but any camber or bump that rocks the rig causes imput to the steering, so you must be ready to manage. You don't need to fight for control, but on most roads you do need constant hands on, unlike a bike or a car.
To anyone who is contemplating the addition of a sidecar to their bike, the best advice is to try someone else's outfit, preferably the same bike and sidecar as you want, and one that the owner says is properly set up. And keep in mind that it will always be a hybrid compromise: when you modify your bike, it won't be as good as a solo bike, nor will your combination be as good as a special-purpose set up like the EML.
PARTING
In 1991 our interest turned to boats. Between two boats in renovation, the cars, a truck, the R100/7 solo bike and R69S sidecar outfit, there was not enough room in the garage or the budget for everything. The bulky sidecar outfit had to go. In several months of advertising, only one buyer appeared and he was from South Carolina. He gave $6,000 for it, and came one month to look, came the next month to pay, and came the third month to pick it up in a rented truck. I was sad to see it go, because it was in top shape and had run perfectly for 5 years.