1986 BMW R80
Seven days or, more specifically, seven nights. That’s about how long it took to turn what you last saw of my 1986 R80 (MT #277) into this triple-ristretto beast. Unlike the big man upstairs, however, my creation is hardly complete so, until then, there shall be no rest.
What you see before you is just a mock-up using rattle-can paint and self-adhesive pinstriping. There’s still much to do properly but delve a little deeper and much has been mechanically upgraded.
The urgency to get it up and running came when MT’s wise counsel explained that to ride your own motorcycle – as opposed to a test bike – is “the done thing” when attending ‘Chumps’, a long-held annual gathering of Australia’s motorcycle media in a nominated tin-pot town. So with much-needed help from Pat, my time-generous, super-handy mate, we tinkered away for seven straight nights until our brains burned and our better halves baulked.
Since my R80 last featured I’ve been quietly giving the credit card a flogging to accumulate a heap of parts. Tarozzi rearsets, tiny mirrors, LED indicators, smaller lighting front and rear, aluminium top triple clamp, a curvy engine cover to fill the airbox hole and a tiny lithium-ion battery with the footprint of an iPhone. The priciest part to date has been the MotoGadget mini speedo, at 200 Euros, but it’s a lovely, high-quality part and crowning centrepiece for the bike. Please don’t tell my wife. Then there are the little, miscellaneous pieces that suck up time and money such as various-size nuts, washers, bolts, hoses and the necessary tools. Got a 41mm ring spanner? A 17mm Allen key? I do now.
I’ve acquired everything online (see breakout) from the UK, the US, across the Nullarbor and up the road, all with speedy service. The project has actually been a fairly cost-neutral exercise, as I have sold many of the original parts to a lovely bunch of readers. The stockpile has since grown so email me (Chris.Harris@BauerTrader.com.au) if you’re interested (see breakout for parts list).
CALL IN THE PROFESSIONALS
Unforeseen expenses (and an indulgent one, more on that later) come during a tune up at BM Motorcycles in Melbourne’s outer east. Some whining is discovered and the driveshaft is suspected, but it is in perfect condition and the noise turns out to be from the gearbox. No point putting off the inevitable: it’s rebuild time. With the gearbox out, the tired, non-genuine clutch plate is cheaply replaced.
BM guru James MacDougall explains an achilles heel of these gearboxes: all it takes is one simple tension spring to break – a common fault due to the gearbox design – and the gearlever cannot return to centre, thus jamming the gearbox. The flaw is apparently more common on harder-ridden GS models than it is with road-going Beemers, but still common. James has a solution that gets around it, which he says “only helps to further delay the inevitable”, albeit by several thousand kilometres.
With a waiting list of up to three weeks at BM, I also use the opportunity to improve the R80’s soggy front end with a pair of progressive HyperPro springs and dampers for a better-controlled ride, courtesy of Walter at Your Suspension Shop in Adelaide.
The improvement is immediate, with far greater control and cornering keenness but there’s still some way to go with the fitting of fresh rubber and lowered fork.
First cab off the cafe rank is to remove the entire rear section, including the seat/rear sub-frame which is as simple as undoing four nuts and disconnecting the electrical junction plug. You’ve got to admire German precision – everything bolts off. This immediately impacts the look of the monolever bike and the idea of converting it into a stubby bobber is extremely tempting.
Pat digs out the spindly rear sub-frame I bought, and promised I wouldn’t use, as a temporary means to fit the new, cafe racer seat. I still hate the sub-frame because it’s cheaply made, doesn’t complement the BM frame and needs major modifications anyway. Pat laughs at the challenge, wheels out the MIG and adds an entire rear section to mount indicators, a taillight and a neat bracket for the lightweight battery under the seat cowl. Another bracket is welded for the robust ignition barrel (from a forklift), which is now tucked away under the tank.
The old and new batteries are like David and Goliath; the weight difference is incredible. The original battery housing is turfed in the valuable junk pile and the frame is ground smooth and painted. This gives a greater sense of openness and we get to work on the new engine cover. The rounder, submarine-like cover completes the look of the engine with the airbox removed but using it means losing some of the original cover’s detail, ‘BMW’ insignia and vents for the engine breather. Our solution? Get out the angle grinder again, merge the pair then get the drill press to make way for a mini air filter to connect to the engine breather hose. Perfect. To copy me means to credit me.
Other mods at the rear include cutting a hole to neatly integrate the taillight, and fit the rearsets and a side-mounted rego bracket that says F-you to the constabulary.
Much has changed up front. Most noticeably, we’ve pushed the forks through the new top yoke for a lower, meaner stance. The clip-ons are on and wrist-heavy, the new headlight is several inches smaller than the original and the penis-pump-like fork gaiters have been binned, along with the front guard. Yep.
With most of the wiring complete, Pat and I take it out for a late-night, shake-down ride. It turns out to be more of a midnight parade and I’m not used to attracting so much attention. The bike is significantly quicker having endured a second, drastic diet. I can’t wait to put it on the scales.
Everything is secured with Loctite and few adjustments are required. We’ve finished the night before I’m due to head off with Groff and the others on airheads to Chumps. Pat and I hit the local cafe strip to stir up the bejewelled sports bike heroes. That’s right, boys: one in a million, not one of a million.
The next morning, I’m ready to ride 500km with the other airheads (a story was planned). I wave goodbye but only make it to the end of the street before disaster strikes. The friction point is a tad higher with the new clutch plate and rebuilt gearbox and I’ve stalled it. No biggie, but it won’t start and the electrics are dead.
This actually hasn’t been the morning’s first electrical problem, with a flat battery in the family car. RACV jump starts the wagon, then returns to replace its battery given my absence for the next few days. Now my bike is dead. Fortunately though, Mr RACV battery man is attending to our car as I roll back up the street. He jump starts me, checks my battery and discovers it isn’t charging with a handful of revs. Why?
At this point, I have two options: take the crappy press bike that shall remain nameless to rendezvous with the others or do whatever it takes to fix it and roll on like a lone wolf. Pat and I have put far too much blood, sweat and the odd tears into our seven-day project to give in this easily. Chris Roberts at BM offers to look at it straight away. “Hello, Mr RACV tow truck?” What a day.
The boys at BM Motorcycles are somewhat taken aback by the R80’s major makeover and even ask if it’s the same bike they worked on. With a fully charged battery, James has the multimeter out to check for a loose connection or anything obvious. Our wiring is flawless, thanks very much. Turns out the diode board isn’t exciting which, in turn, isn’t charging the alternator. It appears the circuit isn’t complete but it’ll be fine now at highway speeds. I hit the road for 500km bound for Jingellic on the NSW side of the Murray River. That’s one hell of a shake down.
The ride to Chumps is a story in itself, including rolling into a servo forecourt completely dry and my backpack coming apart to spill my belongings over hundreds of metres on the Hume Highway. At least the bike’s fine… that is, until the following day when the electrics die again while on the move. The bike comes home on a trailer and I hitch a ride on the back of a Road King (thanks Ned). Could’ve been worse.
The solution to my electrical woes is to fit a tiny globe from the instrument cluster to excite the diode board. Multimeter on the battery, a handful of revs and the volts are climbing! Hallelujah!
BONZA AT BONANZAIf you were at this year’s Broadford Bike Bonanza on the Saturday then you might’ve seen my bike stretching its legs. As a token of my appreciation, I let Pat have first dibs, and pop his track cherry. He loved it and is seriously infected by the thrills of the race circuit. Then it’s my turn.
The track is busy when I have a go but it doesn’t stop me from having fun. The BMW is humming along with plenty of low- and mid-range pull out of turns. I get plenty of speed on the straights but the lack of stopping power prevents late braking. I need better brakes.
NO SUBSTITUTE FOR CUBIC INCHES
After countless nights trawling the web for the right parts, I couldn’t resist also looking into performance gains. The biggest benefits have come from slashing a heap of weight from the bike and putting myself through advanced rider training, but I can’t resist the allure of a 1000cc kit. Screw it, why not?
Chris at BM Motorcycles says the big-bore kit from HPN, a German mob of 1980s Dakar fame, is the one to go with as he’s fitted it to plenty of R80 G/Ss.
The kit comprises two Nikasil-coated barrels, stainless pushrods, high-compression pistons (9.5:1), rings and gaskets. Interestingly, HPN claims a 26 per cent rise in maximum power output as well a 30 per cent torque increase throughout most of the rev range. There’s no need to alter the original exhaust, head or jetting. Those are serious performance claims so, in the name of investigative journalism, let’s put it to the test.
The bike gets dyno’d before the kit goes on at Tune-In Motorcycles in Ringwood, around the corner from BM. Luke gives it three runs and the magic figure is 42.2 horsepower at the wheel. Not bad, given these left the factory in 1986 with 50hp at the crankshaft.
The kit is fitted but, now with higher compression, the original Bosch starter motor just isn’t up to the task. In goes a later-model Valeo unit for a higher kilowatt rating while drawing a third less current from the battery.
The motor now needs to be run in for 1000km – no more than 4000rpm for the first 500km and 4500rpm thereafter using 75 per cent throttle, tops. After that, it’s back to BM to adjust valve clearances, tighten things up and add fresh oil. Even within the run-in parameters, the extra dollop of torque is immediately noticeable – it’s simply quicker while using fewer revs.
I also have a head-over-heart moment and opt for more contemporary Michelin Pilot Activ tyres, instead of Avon RoadRiders or sexy-but-shit Firestone Champions and Coker Diamonds as planned. I like to ride with confidence and enthusiasm. Sintered, HH-rated pads are in, too.
Heaps. We’ll tear it all down to detab the unnecessary bits from the frame and Pat, the self-taught mastercraftsman, will make a new subframe. We’ll then paint everything black including the frame, tank, seat, wheels and engine. After the 1000km run-in, it’ll be back on the dyno to put those claims to the test. Can’t wait.
RESTORING OR TRICKUP IN A BMW?
1986 BMW R80
Type: Air-cooled horizontally opposed twin with two valves per cylinder
Bore and Stroke: 84.8 x 70.6 mm
Compression ratio: 8.2:1
Fuel system: 32mm Bing carbs
Type: Five-speed constant mesh
Final drive: Shaft
CHASSIS & RUNNING GEAR:
Frame type: Double loop tubular frame with bolt-on rear sub-frame
Front suspension: Telescopic fork with hydraulic shock absorber, 175mm travel
Rear suspension: YSS monoshock with preload adjustment
Front brakes: Twin-piston Brembo calipers with 285mm twin floating discs
Rear brake: 200mm drum
DIMENSIONS & CAPACITIES:
Wet weight: 227kg*
Seat height: 807mm
Fuel capacity: 22L
WHEELS & TYRES:
Front: 2.5 x 18-inch alloy with 90/90 R18 Metzeler Lasertec tyre
Rear: 2.5 x 18-inch alloy with 120/90 R18 Metzeler Lasertec tyre
Max power: 37kW (50hp) at 6500rpm
Max torque: 58Nm (42ft-lb) at 4000rpm
Price when new (1986): $6690
* Quoted factory figures when new