I ignored the warnings about buying an ex-police bike that had been converted back to road spec. The mileage was reflected in the price. Over 200,000 miles and £400. The police siren and flashing blue lights were, unfortunately, conspicuous in their absence but a bloody great barn door of a fairing, as well as large panniers and top box, made up for that.
Inevitably, with a BMW of this vintage and age, the gearbox action and shaft drive reaction were the most prominent sensations in the first couple of days. All kind of descriptions have been filed on the notorious gearchange action, but as an old BMW hand it was only really notable for its clunk, clunk, clunk, crunch on every gearchange. Even with a full load of gear, the mule weighing close to 550lbs, there was plenty of torque available from the OHV boxer engine. Once under way there wasn't much need to play with the gearbox.
The other malady that commonly afflicts old boxers, a breed apart, turned up after a couple of weeks. A slipping clutch made the gearchange action completely impossible, like trying to take a virgin when drunk out of your head. The clutch failure is so common that there are several options but experience has taught me that it's better to stick with stock parts - it's a lot easier to cope with a slipping clutch than one that explodes, sending bits of metal all around the motor. It was just an afternoon's work to fix the clutch (but only if you know what you're doing).
A new R75 motor makes about 50 horses, enough to put out a reasonable 110mph. The thing to remember with BMWs is that top speed is often a usable cruising velocity and the bikes are set up to cover long distances in less time than apparently much more powerful machines. The BMW's power is always usable, the comfort levels are high and the range better. A lot of minor ingredients come together so well in boxers, that the whole is much more than the sum of the parts. But it takes a good six months to reveal its true character rather than mere minutes with the bright and brash Japanese motorcycles.
My bike was only good for 90mph, which, again, turned out to be the maximum cruising speed. Part of the loss of power was down to the aged engine, the rest down to the weight and poor aerodynamics of the acres of plastic. The fairing gave total protection and aided biking adventures in the depths of winter. However, unlike BMW's RS fairing, the faster the hulk went the worse became the steering. The air battled against the fairing so strongly that it seemed to sway about on its mounts, despite their tank-like construction.
Generally, boxer handling on twin shock models is a little ambiguous. The suspension travel is a bit too long to maintain integrity at motorway speeds. The rear swinging arm mounts, in particular, allow some large weaves to enter the scene at 85mph, which the OE suspension and shaft drive do little to eradicate. Police spec bikes have heavy duty suspension, both to compensate for the extra mass and to reduce the travel to more sensible levels. It does nothing to stop the chronic back wheel hopping but speed wobbles are as rare as a slow RD350LC rider.
My bike had refurbished, stiff suspension and newish Metzeler tyres that were a touch wider than recommended. The handlebars were relatively tall and wide, giving a relaxed posture behind the GRP and plenty of leverage. The great mass of the engine is carried low, removing most of the top heavy feel that usually goes with these style of big cruisers.
The steering was awesome in its accuracy, which aided in thrusting the wide, wide BMW through borderline gaps. The ground clearance was good, only during really insane moments did the cylinder heads touch down - by then the tyres felt like they were ready to let loose. Stability, if the intrigues of the back wheel were ignored, was good enough to maintain 90mph cruising even on neglected A-roads. Even the poor aerodynamics in strong winds failed to really throw the bike way off line.
The Metzeler tyres were, it seemed, perfectly matched to the boxer's chassis. Not that surprising as they both evolved together in the same country. Their grip in the wet, along with the plastic's protection, made the BMW ridiculously easy to roll through the worst weather the English climate could throw at us. Here, the Teutonic wonder-horse showed its true mettle, leaving plastic reptile mounted mates in clouds of spray as we sped securely off into the distance. They wondered what the hell had hit them, how some 20 year old relic could scamper off at twice their presumed safe velocity.
It wasn't all roses, though. The BMW was afflicted with a pair of plain nasty discs out front. They perfectly illustrated all the faults inherent in seventies discs - fade, wet weather lag, sudden screaming noises, seized calipers plus a curious design connecting the brake lever to the master cylinder (with a cable to the remotely sited cylinder). I never really knew how they were going to play on any particular day or occasion.
After a month they intruded so deeply into my otherwise happy state, that I tore the whole rotten lot out, replaced them with a much newer set. It was a lot of hassle and hard work but at the end of the day I had a comparatively blissful front brake that worked both well and predictably. Even with that happy state of affairs, pads only lasted 8 to 10,000 miles, when the calipers would need a bit of a clean-up.
BMW even compounded the braking insult by a fitting disc brake to the back end where the caliper was perfectly placed to pick up all the crap thrown off the back wheel. Gratifyingly, my machine was fitted with the well regarded drum. At least it's okay for the first half dozen years but eventually the spindle will seize up, probably down to all the brake dust that fills up the drum over the years - shoes last 20-25,000 miles.
The drum reacts well with the shaft drive, a bit of gentle pressure when slowing in bends helps intensify the feeling of stability. Boxers are not the kind of bikes that can be thrown every which way regardless, preferring to be set up on line well in advance. With taut suspension the chances of surviving a quick change of direction in bends was greatly enhanced. On soft suspension, the shaft drive would wind up the springs and the chassis would bounce all over the place. Having owned half a dozen questionable boxers, this one impressed more than it surprised.
Which, when you think about the mileage, is rather majestic, but then the chassis is well made and can easily, perpetually, be upgraded over the years. Parts' interchangeability between different models of vastly different ages is good, so a large amount of mixing and matching is possible, to produce the kind of bike you really want rather than just accepting what the motorcycle manufacturer churns out.
Somewhere along the line, the R75 had received electronic ignition, polished valvegear and a newish set of carbs. Old Bings are scandalously intemperate items, needing the same kind of constant care and attention as a 100,000 mile Ducati single. The new carbs need a touch of balancing every 2000 miles, which is neatly enough the time when the valve clearances begin to go out of adjustment.
Any boxer engine of this kind of mileage has received some heavy attention, let alone an ex-police bike. Common failure points are the timing chain, generator, clutch and valves, with the rest of the motor often lasting for 100,000 or even more miles. Neglect and abuse, though, can have the bores, camshafts and gearbox trying to go into a self-destruct routine before 50,000 miles. Police bikes had the benefit of regular, proficient servicing but were ridden harshly by hard-core motorcycle plod, whose insane grins often gave the game away. I'm sure the majority of them were in it for the kicks more than anything else. The true history of my bike is obscured in the mists of time, but it's obviously one of the honourable survivors.
When I looked deeply into the machine there were lots of neat touches, despite the fact that the last owner had let a layer of grime obscure them. In the three months and 4000 miles he had the bike I don't think he bothered to clean or service it once. Just rode until he decided it was time to move on to something better.
Some of the alloy brackets were anodised, engine internals polished brightly, a first-rate stainless steel exhaust system fitted (the stock one starts to rust within two years), the electrical wiring looked recent and was fitted with aircraft quality connectors, and all the screws were chromed allen bolts that were a pleasure to undo rather than a ten hour horror story, as is the case with too many Japanese bikes.
I shouldn't have been that surprised to have got 24000 miles out of the BMW before any serious problems turned up. I became so impressed with the R75's ruggedness that I was quite content to do 1000 to 1500 mile long weekend excursions. It was on one of these, some 400 miles from home, when the gearbox began to disintegrate. Horrible grumbling noises followed by a loss of all transmission. The actual gearchange action had gradually become more and more noisy, less and less likely to engage gear. I was going to get around to renovating it.....after an AA trip home, I found that teeth had stripped off their cogs and caused all kinds of interesting carnage.
A complete gearbox renovation was done, using a combination of new and used parts at a cost of £175. I could've bought a used gearbox for that kind of money, but would've had no idea if it was any good or how long it was going to last. I found the gearbox pretty nasty to work on, with too many spacers and with parts from too many different sources difficult to assemble. I also put in a newish clutch unit as the action had gone very vicious (not that BMW clutches are the most subtle of devices even on a new machine).
Did I have the feeling that the bike might be near the end of its life? No, not until another 7000 miles had been covered and the shaft drive broke. Actual breakage of the shaft is very rare on boxers, usually only coming as a result of more than 250,000 miles worth of abuse. There are lots of boxers in breakers, so spares were available, at a price. The final miles of the shaft had been spent whipping about in a resonant frenzy, wrecking the gears at each end, so about two hundred quid had gone west by the time I sorted out the beast.
By then performance had lost a notch, leading me to think that within the next 5000 miles it'd need a rebore, new pistons, a valve job and, knowing my luck, a rebuilt crankshaft. It'd be cheaper to buy a used engine than mess around with all that hassle. The cosmetics I'd kept in nice shape, so overall appearance was good.
To recover some money I ripped off the fairing, panniers, top box and rack, selling them for just under two hundred notes. I then spend fifty quid buying used bits to bring the bike back to stock R75. The end result of all that hassle was a more than reasonable £650 sale.
In conclusion, these old boxers are tough, albeit agricultural, old buggers but whether they will last any useful distances is all down to the luck of the draw and the pleasure of the gods. Buying a low mileage BMW shouldn't provide too many moments of horror but buying an ex-plod bike that's been around the clock a few times is a whole new adventure. Having experienced it once, I was impressed with the ease of running but not so delighted with all the mechanical hassle once the motor started to fail.
The best deal is to find a good chassis for a couple of hundred quid and fit a much newer engine and gearbox. I haven't taken that sound bit of advice, naturally, just splurged £1200 on a really nice, 22000 mile BMW R80/7. I'll let you know how I get on.
Des Lawrence