Getting up close and personal with a BMW R90S
Style and substance make the R90S BMW’S undisputed champion boxer
Take one look at a BMW R90S and tell me it isn’t the best-looking BMW ever built. I can’t hear anyone. And that’s because either the Smoke Black and Silver or Daytona Orange and Silver versions still look fabulous today, 47 years on from when they first stunned the BMW faithful back in late 1973. The Hans Muth-designed R90S was the first BMW to really cash in on the sporting success of the marque and did much to refresh BMW’S worthy but slightly staid image. Today, they’re the most sought-after of all post-war aircooled BMW twins.
The heritage of the R90S is the 1970-73 /5 series, and the /6 models lean heavily on the design of their immediate predecessor. The /5 series revived the flagging commercial fortunes of BMW’S motorcycle division and, while they may not have been one of the most flamboyant examples of motorcycle design, they established a fine reputation for engineering excellence and build quality that would lay the foundations for BMW’S subsequent success. And it was the production racing 750/5s of Helmut Dähne and Otto Butenuth that almost certainly opened the door for the development of the R90S, which many regard as BMW’S first superbike.
BMW’S established reputation for high-mileage reliability carried over into the sporting S variant of the /6 range. Unless maintenance has been scrimped on, mechanical failings are pretty much limited to the occasional failure of the gear selector spring (one of the few real design shortcomings of the /6 series design), some valve seat recession and the potential for valves to break at high mileages.
There’s not much you can do about the selector spring – and it’s an engine and gearbox out job to fit a new one. Some break, some don’t, but always check the gearbox for a positive change before you buy. Valves should be changed at 60,000 miles or less and, if it’s difficult to set the valve clearances, valve seat recession may well be to blame. A top-end rebuild including new valve seats would sort it out for another 60,000 miles. The bottom end of the engine is legendary for its durability, though, and mileages knocking on 200,000 are not unheard of for /6 series twins.
Otherwise, the R90S is a great rider’s bike and remarkably practical as a daily rider, too. The brakes were top class in 1974 – and they’re still perfectly adequate today. Likewise the handling and electrics. The original coil ignition works well enough, but electronic ignition conversions are readily available and cross off another job at service time. The finish is a cut above just about all of the bike’s contemporaries, though. The beautiful graduated paint was hand-applied at the factory – so if you need a respray, finding a painter capable of matching it might take a little research... and cash.
The R90S was widely praised by
‘IT’S REMARKABLY PRACTICAL AS A DAILY RIDER’
the press at its launch – both for its outright performance and all-round ability. ‘Possibly the best production motorcycle in the world,’ was LJK Setright’s opinion in Bike magazine, while his colleague Bill Haylock wrote: ‘BMW’S flagship, the R90S, may not be the ultimate, but it’s probably the nearest anyone’s got to it yet.’ Even the R90S’S £1799 price tag – which was three times the price of a new Bonneville – didn’t dampen his praise for the flat-twin. ‘No matter if you have to beg, borrow, rob, or put yourself in hock to get the loot, it’s worth it,’ he continued. Praise indeed.
With a 124mph top speed, the BMW might have given away a couple of miles per hour to Kawasaki’s Z1, but in the real world of winding roads with indifferent surfaces and weather conditions, the R90S could more than hold its own. But it was the ability of the bike to cover huge distances effortlessly, comfortably and reliably that were most
impressive. And the R90S is one of perhaps a handful of classic bikes that can still deliver that. If that sounds like your sort of machine, it might just be exactly the bike you’re looking for.
THE RIDE
Riding a BMW is a different experience to piloting most classics, but it’s one that can be a real pleasure, too. There are few better classics to cover some serious distance on than a big BMW flat twin – and the R90S is the coolest of the lot. The riding position is superb, vibration from the engine is minimal at normal road speeds and the seat is a broad and comfortable. The controls are light and, aside from a slight lack of feel from the cable link from the front brake lever to the master cylinder, they function as well (or better) than on most classics. There’s no doubting that the R90S has been designed and built as a real rider’s bike.
Probably the first thing you’ll notice, if you’ve just stepped off a chain-driven bike, is the torque reaction that rocks the bike from side to side when you open the throttle. It’s not alarming – but it does feel slightly alien at first. But it’s something BMW (and Moto Guzzi owners) learn to accept. The other obvious quirk is the gearchange. Even diehard BMW fans have to admit the BMW gearbox is not the slickest in town. That’s a consequence of the cartype, engine-speed clutch – and it’s something else BMW flat-twin owners just have to learn to get used to. The trade off, though, is a light action and long life – a good job, as replacing the clutch means dropping the gearbox out.
If all this sounds slightly negative, it really isn’t meant that way. The good points of the R90S easily outweigh its idiosyncrasies. Take your time with gearchanges and you’ll be fine. Once you’re in top gear and rolling on a fast A-road, the torquey engine means you can
ride the S on the throttle and enjoy the fine-handling chassis to the full. A top speed of 124mph for a mid’70s pushrod twin isn’t to be sneered at. But its ability to maintain improbably fast average speeds up hill and down dale that remains so impressive, even after 46 years.
Riding the R90S invites you to make comparisons. Is it the fastest bike of its era? Not quite, Kawasaki’s Z900 edges it out. Is it the best handling? Maybe the Ducati 900SS shades it. Has it got the best brakes? Close, but perhaps the Ducati has it. But a ride on the R90S invites other comparisons, too. It’s more than the sum of its parts, which means the R90S is a sublime classic all-rounder. If it were a gymnast, it might not win any of the individual gold medals, but it would probably take the overall title. That takes some doing.
And even when your ride finally comes to an end, the R90S continues to perform, attracting attention for its classic good looks and fabulous colour scheme. It never hurts to look good – and the R90S is, without doubt, the coolest of all BMW boxers – especially in Daytona Orange. And cool never goes out of fashion.