When the opportunity to fully test my work came at Monday lunchtime, I geared up in leathers and a full face and headed for the road.
Again, I tiptoed around my neighborhood, stopping for a brief roadside ‘has-anything-fallen-off-or-caught-fire’ roadside inspection. Having cleared pre-flight, I turned right on Maryland Route 180, and headed for my favorite set of near-the-house twisties. The first thing I noticed was a strange absence of noise from the cockpit, which had formerly been a rattling mess. Apparently, the rubber fairing seal provided a great deal more support and vibration isolation than one would suppose any mere rubber band was capable of. The cockpit now seemed far more solid and finished than it ever had previously.
With everything in the transmission newly installed, and no doubt requiring some bedding in, I was very judicious on my use of the throttle – smooth openings and no full honk for a least a few miles. Shifting the box at 5000 rpms instead of 3500 confirmed by initial impression – Mark Delaney had somehow built the best BMW gearbox I’d ever experienced from a collection of bits of questionable provenance. Shifts were positive, sliding into place with a firm, Teutonic thonk – thonk – thonk – thonk – right through the entire gearset. I was nearly ecstatic.
Ecstasy, though, was exceedingly short lived.
One of the characteristically wonderful things about a properly setup carbureted motorcycle – and a defining characteristic of the R90S – is the perfectly tractable bottom to top response curve that opening the throttle anywhere in the rev range provides. It has taken the designers of Fuel Injection systems a very, very long time to even get digital systems in the same game with as properly setup carburetors when looked at in terms of flexibility and tractability. If Fuel Injection tends to be digital — on/off — then a bike like the S is determinedly analog — a smooth continuum from less to more.
How this works is plainly evident on any tight, technical backroad. On my R90, one can begin opening the throttle slides just before the apex of a corner, and even if the engine speeds are somewhat below the engine’s torque peak, the exhaust note will go hard, the bike will set the rear tire, and will slingshot out the corner exit and up the next straight. Corner entries that are properly anticipated can be managed in a similar way through a judicious roll out of the throttle at the right point on entry. On rollercoaster roads with rises and falls on straights and corner exits the S bike will unload its forks, you’ll hear the ‘thunk’ of top out stops, and the bars will go light in your hands as the R90 power wheelies in any of its bottom three gears. The broad torque of the S motor and its DellOrto PHM 38 Accelerator Pump carburetors make backroad dancing pure bike jazz.
This was that feeling that led me down the road of ministering to a tired, nearly 40 year old motorcycle. This was what sustained me while aching hips and knees were getting bashed around the concrete slab of my garage floor, and while my hands were getting bruised from wrenches and being knocked off frame tubes, and while my skin was absorbing enough grease and my own blood from manifold cuts and scrapes for me to despair of ever looking clean again.
And when, on that test ride, when I finally set up for a corner exit at about 3400 rpm, and firmly rolled the throttle open, that peak nearly moto-erotic experience was exactly what wasn’t there.
At the point where the S would normally dig in, grunt out a hard edged “WHaaaaaaah…”, and do that intoxicating slingshot thing, the tach needle snapped up, the clutch skipped out, and basically nothing happened.
I knew instinctively what mistake I’d made, what was wrong, and what I was looking at to set it right.
I felt as about small as I’ve ever felt. My disappointment knew no bounds.
I’ll admit I rode the bike this way for more than a little while. I’d experienced a few airhead clutches that were slightly subpar after this kind of service, and most of the time they ran through it. After a few miles, whatever contamination was present was worn off, friction surfaces remated, and all was right with the world. You can be forgiven, if this ever happens to you, for thinking that things might improve. You can be forgiven, but take it from me, things will never go back to being perfect. Over more than 1000 miles, things did improve slightly, and the rpm range where power could be used widened, but at root, this bike had been essentially gelded – the very bottom and very top of the usable rev range had been removed, and the essential spirit of this motorcycle had been exiled.
There was going to be more dollars and more quality garage floor concrete slab time required if everything was going to be set aright.
There were a few other things that required my attention in addition to the results of my own stupidity.
I had a set of factory BMW touring cases that – while they were cosmetically rough – were functionally far better that the Krausers that came with the bike. With the exception of one of the frame latches, which was visibly cracked and could be expected to expire sometime in the next 12 minutes or so, they were all there and would be perfectly serviceable after some care and attention. I ordered up a case latch – which had to come from Germany – and a rivet gun.
I’ve broken more airhead case latches than I care to recall. Every time it’s happened before, I would take the case to a dealer, who would sell me the latch and then charge me to rivet it on. I was determined to be as self-sufficient as possible here, and the $10 that a Stanley Works rivet gun cost me at my local Wally World seemed like a good investment. A few minutes of practice and few minutes of attention repaired the frame latch on this case.
These cases, as mechanically sound as they might be, were distinctly not pretty. They’d been painted a highly metallic grey to match my /5, and then been subjected to roughly 15 years of boot scrapes, being banged off of bright yellow-painted parking lot divider pipes, having their front corners ground off by being touched down in corners, and at least one major crash where the /5 had taken a 20-30 foot slide resting on top of the left case.
After completing the latch repair, I rode back and forth to work with them for a few days, just to make sure they were going to survive in daily use. At that point, I finally smacked to the ugly limiter – hard – and went searching for a solution. The Adventure Riders came through again, as they had a whole thread about painting hard cases with pickup truck bedliner paint – complete with good quality pictures that convinced me these were going to look better than new ones when I was done.
And so we had another trip to Wally World. Their automobile department had Rust-Oleum brand aerosol bedliner paint in two colors – matt sand and matt black. I went with the black. Their hardware department had 3M Blue Painters tape. Total budget – $9.
Upon arrival home, I unbolted the case lids and lightly sanded them with a palm sander and some fine sandpaper. I washed them with a damp rag to remove the sanding dust and then spent a few minutes masking off the badges, reflectors, latches and trim on the cases. I took a large piece of cardboard and laid it outside on my lawn, and laid the saddlebag lids down on it. I coated the lids once, waited 20 minutes and coated them again. An hour later, they were ready to put back on the bike. I was absolutely stunned. They looked nothing less than great – Imagine what a brand new Krauser case looked like in 1975 and you get close, only the pebble effect on the surface was somewhat finer. Even the spots where there were substantial gouges were essentially filled – one could only see them if you knew where they were beforehand. Best $10 fix ever, bar none.
I mentioned Ham Pugnus’ attachment to bad 80s vintage adhesive BMW Roundels. This is a head scratcher, because the R90S is one of two 1970s vintage motorcycles that still had actual cloisonné enamel tank badges. Lord only knows, and I will not speculate as to what happened to the original ones from this motorcycle. BMW does still sell the OEM ones, but they retail for over $50 a badge. While I may think, in my purely biased way, that my motorcycle is attractive, it certainly is never going to be entered in, much less win, any vintage motorcycle shows. A certain regional enthusiast BMW dealer has commissioned some reproductions of the original cloisonné badges, and they are visually indistinguishable from the originals. At $24 a side, I could rationalize it.
Installing them was straightforward. I loosened the adhesive on the yellowed badges with a blow drier. I passed a few strands of dental floss behind the roundels to serve as an improvised flexible hacksaw – it was quite effective at removing the old badges. After removing the old adhesive residue with rubbing alcohol, I used 3M automotive trim double sided tape to position and affix the new badges.
It’s amazing how something as small as a tank badge can have an almost talismanic effect on the whole presence of a motorcycle. Whereas – with the yellowed, cheap badges in place, the bike looked sad, neglected – it now somehow had acquired a presence, an aura. This simple touch had taken us all the way from donkey to thoroughbred.
To continue reading, Part Eleven of the story can be found here…