In Praise of the AIRHEAD
BMW’s anachronistic air cooled flat-twins have become the new black. Some people are restoring them, other people are turning them into café racers. What all those people should actually be doing, argues Martin Gelder, is just getting on and riding them…
Odd. Odd looks, odd engineering, odd handling, odd sounds. Odd owners, some would say. BMW’s motorcycles have always been a little to one side of mainstream, but the things that make them odd are obviously the result of development by a team who rode the bikes they built. The best way to understand, to appreciate, those oddities is to ride a BMW as intended. So let’s take a 1977 R80/7 for a day trip to the seaside.
The bike sits on its centrest and with its front wheel waving proudly in the air, but there’s method in this madness. If you need to remove the front wheel, it’s easy. And if you have to remove the rear wheel, the change in balance as that wheel is parted from the bike will tip the plot gently forwards about the centrest and so that it rests on the front wheel. Magic, but for now we can leave the wheels in place.
Roll the bike off the stand, climb aboard and the BMW settles on its long travel suspension. There are two fuel taps that click satisfyingly as they are switched from off to on, and that have a full 360 degrees of rotation; down is on, up is reserve, and forward or backwards is off. Click, click, click. When it’s cold and dark and you’re fumbling for reserve in the outside lane of a busy motorway, those clicks are a marvellously reassuring confirmation; fuel will flow. The choke lever seems oddly placed, on the air filter cover above the gearbox, but sit on the bike, put your left foot on the peg and drop your left arm so that it hangs below your thigh, and there’s the choke lever in easy reach. It’s not so much that the controls fall easily to hand, more that your hand falls easily to the control.
The key is a strangely constructed fold-flat, hinged device that makes sense when it’s inserted into the ignition switch hidden in the left hand headlamp mount. The key that was flat in your pocket is now a convenient rotary switch. The starter button on the righthand bar is shaped for a gloved thumb, the kill switch shaped to show which position it is in. Below the starter is the indicator switch, a small paddle-like control that sits in easy reach of that gloved thumb. Some might say
it’s on the wrong side, others might think it’s too low down, almost out of sight, or that it moves in the wrong direction, but it’s where your thumb is without having to stretch, and it moves in the same direction as your thumb naturally articulates. Down for right, up for left, it’s possibly the most intuitive indicator switch fitted to a motorcycle, and certainly the best fitted to a BMW for many decades. The left bar has a dip switch that works in the same plane, an easily found horn button and a lights on/ off switch which mirrors the kill switch; one glance tells you which position it’s in.
The R80 shudders as it starts, shaking itself like a wet Labrador as it turns over then fires, settl ing to a high tickover as the choke is mov ved to the half-position detent. As soon as it’s’s running it’s ready to ride. Although you can’tt see the gear lever, nestling beneath the left hhand Bing carburettor, it’s where your foot expe ects it to be. It’s there, you just need faith. The ddry clutch – a single plate car-like item with a diaphragm spring – can be quite sudden and as drive is fed to the rear wheel the
shaft’s helical gear action on the rear wheel’s drive gear causes the rear of the bike to lift as the wheel is pressed into the ground, which can be a little disconcerting if you’re not expecting it.
And we’re off. BMW gearboxes come in for a lot of criticism but familiarity brings smooth changes. There’s a heavy flywheel spinning between your shins, a very direct and sometimes unforgiving connection between gearbox and rear wheel, and that sharp clutch, but adjust to the rhythms of the bike and gear changes are silent and smooth, even clutchless on the way up if you’re feeling confident. The flat twin engine is smooth, almost unnaturally so if you’re used to British or Japanese twins. It grumbles along at low speed, thrums at higher speeds and only really feels busy as you approach the redline.
Motorcycling lore will tell you that the R80s are the smoothest, but in reality a well set-up R100 will be as pleasant and vibration-free. Carburettor balance is crucial to calm the
rocking couple set up between the offset crankpins (the left cylinder sticks out a couple of inches ahead of the right one when viewed from above) but the sweetness of response is worth the effort.
Ah yes, those sticking out cylinders. They won’t touch down, provided you’re using a small amount of throttle to drive the bike round corners. Honestly. On the left the sidestand tang will clatter noisily against the tarmac long before the rocker box touches, and on the right the heel of the brake pedal grinds hard against the road before the head gets close. Some aftermarket crashbars will touch down, and if you’re foolish enough to be forcing a heavily laden bike with tired
suspension into a sharp bend while dragging the front brake... The sensible money would still be on the front tyre giving up before the heads went down, but don’t try this at home.
In normal use, though, /7 Series BMWs are surprisingly nimble. The combination of long travel and soft suspension that was unusual when the bikes were new in the 1970s is now taken for granted on mile-eating ‘adventure’ bikes. The frame is vaguely reminiscent of the featherbed Norton, but with the motor only held at the very bottom there’s a fair amount of give in its structure. The forks are quite steeply raked for a bike of this age, but the low centre of gravity results in a stable platform that’ll flick from side to side quickly when asked.
The ubiquitous Krauser panniers can make things a bit hairy at the sort of speeds only legal on an autobahn and the different styles of fairing available affect stability in different ways... Are we really discussing the stability at three figure speeds of a forty year-old bike? In normal use they’re planted and secure, giving great feedback, particularly on wet roads and questionable conditions.
And that flat-twin engine suits the bike’s relaxed style. It’ll hum along at modern traffic speeds with plenty in hand, it’ll pick its way unobtrusively through town, and do everything in between in a calm, measured way. It’s responsive – and linear in that response – without being desperately exciting. It just... goes. And goes, and goes. Once round the clock isn’t unusual – the bike in the photos hereabouts is a 120,000 mile veteran – and twice or even three times that isn’t unknown. Duplex camchains last a long time, rings don’t seem to wear, plain bearings go on forever. If there’s an Achilles’ heel it’s valve seat recession due to unleaded fuel, but conversion kits are available. That’s all stuff for the workshop though, and with 5000 mile service intervals you’ll spend most of your time riding. The controls are surprisingly light, the levers dog-legged, the seat broad, supportive and a great place to spend a day or two on the road.
Heavy clouds roll in, darkening the skies above the Fens, but the BMW shines. The headlight is an unusually large one with a very well defined dip beam cut-off and a main beam that reaches further than most of its contemporaries. The instruments have a calm green backlight, the indicators are large and bright (if sometimes a little droopy on their stalks) and the horn is so car-like in tone that errant motorists and pedestrians positively leap out of the way when it’s used. Even the idiot lights are well thought out, with the main beam warning dim enough to avoid dazzling at night, bright enough to be seen during the day. There’s a generator light as well as the usual oil pressure and neutral indicators, and the rather worrying ‘Brake Failure’ light is actually just a fluid level indicator for the remote master cylinder hidden under the fuel tank.
You were probably wondering when we’d come to the brakes. They work. Can we talk about the underseat storage area now? No? The brakes developed over the course of the /7 Series model life, and range from adequate to quite good. The first models had a single disc with a pivoting caliper at the front and a large drum at the rear. These early discs were operated by a cable from the handlebar lever to the remote master cylinder, which in turn sent hydraulic pressure to the caliper. Acceptable when everything was new, marginal with a badly adjusted stretched cable, a master cylinder in need of bleeding, and a pivoting caliper that no longer moves freely. Later more powerful models got a second front disc, a rear disc, then fixed calipers made by Brembo and eventually a handlebar mounted master cylinder. Parts compatibility means it’s possible to upgrade earlier
bikes to the later, better, set-up and for all but the gentlest riding it’s probably worth it. A BMW with Brembo calipers, handlebar mounted master cylinder, braided hoses and aftermarket cast iron discs will stop as well as any contemporary bike.
We’re not stopping though; with 24 litres (five and a quarter of Her Majesty’s finest gallons) of petrol in the tank and a comfortable seat all day riding is easy. Rider and pillion footrests adjust for height, the rear suspension has convenient handles to set the preload, there are factory-made screens or fairings and an airhead BMW without a set of pannier looks almost naked. The standard low and narrow bars are great for high-speed cruising, balancing the rider against the wind and keeping him or her out of the worst of the weather. Higher bars give a riding position that is better for bimbling and kinder on middle-aged backs at the expense of fast cruising. Life on a BMW twin is good.
OK, it’s not all good. The battery is a pain to remove and there’s no kickstarter when it goes flat. Some models have a first-aid kit cubby hole that eats into the seat padding and at rest it can be a bit of a stretch to the ground. The sidestand is a work of art with its own little spade-shaped foot that will hold the bike up on soft ground, but it can be hard to operate from the saddle unless you’ve got the knack.
And there’s the image. Less so now than when they were new, but there’s a certain amount of arrogance assumed about BMW
riders. They were bikes bought by some as a show of status and wealth and that
association has stuck. People see you riding a BMW and decide you’re a bit smug, when in reality you’re just more mellow than they are because your bike’s electrics work, its seat is comfortable, its tank still has fuel in it and your neck isn’t aching. All those hipsters buying them up might not be as stupid as they look.
This particular machine was bought as a project with 90,000 miles on the clock. It’s barely needed any attention and just keeps rolling on, having covered another 25,000 miles since then. It’s now fitted with R100 (actually 980cc) barrels and pistons, just to see what difference they made, and a twin disc front end with handlebar mounted master cylinder, because of the difference the bigger bores did make. It’s clean under all the dirt but its role as a winter hack combined with the agricultural back roads in Suffolk don’t make for a concours finish.
And so, two and a half hours after leaving home, we arrive at our destination. It’s the seaside but it’s blowing a gale and the café is shut. No matter. The saddle of an airhead BMW is a great place to be, and there’s plenty of fuel in the tank to get home again. The long way. Time to ride on...