Comparing technology, tradition, and culture in two modern heavyweight cruisers.

By Morgan Gales, www.cycleworld.com

Two of the oldest, most famous motorcycle manufacturers in the world are using all the resources at their disposal to create motorcycles that inspire you, motorcycles that people write songs about and take pictures of everywhere they go. These two machines, the 2021 Harley-Davidson Softail Slim and BMW R 18 First Edition, are, first and foremost, emotionally evocative.

“We want a Harley-Davidson to make you feel something, to come alive, and to instill a sense of emotion.”

In the time of the Harley-Davidson Knucklehead and BMW R 5, there were no micro-specifications or subcategories. Eighty years ago, motorcycles were just motorcycles, products of topography. A 1936 R 5 might look like a sportbike next to a Harley EL of the same year, as the BMW was developed for riding through European mountains and villages, not, say, crossing Kansas. Ever since, H-D has manufactured what is essentially the same silhouette, gradually updating technology as time passed. New H-Ds have new 45-degree V-twin engines, but squint hard at the 2021 Softail Slim and you can see the ghost of an EL. BMW, on the other hand, now has a different motorcycle at the top of every class of bike except cruiser. For BMW, a company known for technical expertise and engineering, this level of focus on visceral emotional response is new.

“One of the most important tasks while devel­oping the new R 18 was to make the bike as emotional as possible.”

BMW’s engineers had several clear goals for the R 18. The new bike had to fit the aesthetic parameters of an American cruiser, including the large engine as the centerpiece. The rider had to feel the bike come alive beneath them as it started up and see moving pieces like the exposed driveshaft. It had to maintain the flat-twin engine, evoke the R 5, and represent BMW’s technical prowess while simultaneously being a true spiritual evolution of the BMW lineage. That’s a lot to accomplish.

Harley-Davidson, on the other hand, has developed the Softail models from a line of cruiser motorcycles stretching back almost a century. The defining aspects of the cruiser genre exist naturally within Harley-Davidson models because modern cruisers essentially all evolved from Harley-Davidson models. But as the originators of this genre, the company is held to a meticulously high standard. Change cannot come too abruptly or without serious consideration. As Cycle World Technical Editor Kevin Cameron said, “If you get the heritage part right, get the proportions, the colors, the unspoken but clear message right, you may earn the right to move ahead with change.”ADVERTISEMENT

So Harley-Davidson’s flagship line has progressed from what were once very loud, massive, shaky machines into relatively refined vehicles which still preach the silent message of the great American freedom machine. This refinement has come with decades of work, exhaustive study of customer desires, and extensive real-world testing. Three new laboratories have been built over the past two decades specifically for tuning sound and vibration.

The Softail’s Milwaukee-Eight engine is solid-mounted to the frame and 100-percent counterbalanced. The transmission of secondary vibration to the rider is controlled through touch points that vary model to model. For example, on the Slim, rubber-mounted handlebar risers and floorboard panels on bushings relay a steady combustion-pulse feeling, only really shaking hard for a moment with initial throttle application. That shake makes every crack of the throttle a joy. You have likely seen and heard the effects of this as Harley riders rev their bikes at stoplights. The engine sings beneath you under acceleration, and a rider can feel the hum of combustion in the best possible way.

When parked next to the R 18, little pieces that wouldn’t normally attract much attention, exhaust clamps and the like, suddenly jumped out.

To achieve the desired cruiser feel, BMW’s R 18 engine was given its distinct pulse by omitting the balance shaft used on the company’s smaller-displacement flat-twins. Bearing in mind that peak torque was measured at 2,880 rpm, this omission was intended to provide enough vibration to tell the rider the engine is alive, but not so much that it would become irritating, especially as the redline was set at a low 5,500 rpm. The Rock ride mode applies a programmed-in shake and asynchronous rhythm to the idle, and is paired with the most aggressive of three throttle/fueling maps. The big boxer punches to life with a pull to the right, thanks to the longitudinal crankshaft and considerable flywheel effect. Any increase in throttle input torques the bike to some degree. Rain mode has an obvious application, but Roll was only used enough to determine that Rock is where we want to be, and that vibration at speed is the same in all modes.

As revs climb past 3,000 toward peak horsepower at 4,800 rpm, that charming pulse feeling morphs into a droning and tiring vibration. My old 1974 BMW R90/6 had a similar endearing pulse at idle, but it smoothed out as the engine revved toward peak power output, which encouraged the rider to take advantage of the whole rpm range. But that old engine is half the size of this one, so even with the inherent flat-twin buzz, it was much less pronounced. In the R 18, that feeling moves from communicative and friendly in the low revs to an incessant buzz, compelling me to shift earlier than I might naturally and discouraging exploration of the upper horsepower range. A firm seat, solid-mounted handlebar risers, and footpegs bolted straight to the frame do little to damp this vibration. Therefore the charming idle so revered and expected among cruisers was achieved, but the bike must be ridden within certain parameters to avoid adverse effects. As Editor-in-Chief Mark Hoyer said, “The R 18 is very focused on the mellow experience, and if you ride specifically within that performance box, it feels great.”

Of course, the 244-pound engine and its two 900cc slugs affect the ride through more than just their moving parts. To fit a human to the R 18, it’s necessary to stretch the wheelbase to 68.1 inches. Even then, mid-mounted foot controls are tucked tightly beneath the massive cylinders, where both our large-footed testers still touched toes to cooling fins. The placement of the cylinders also eliminates any hope of forward foot controls or floorboards, staples of any cruiser acces­sory catalog.

When it comes to appearance, BMW has done an incredible job. At the R 18 launch, BMW Director of Design Edgar Heinrich said, “In every detail, there must be love.” This shows in the motorcycle’s high level of finish, crisp lines, and lack of clutter. Wires, clamps, and bolts are all tucked neatly away. The R 18 draws from the company’s own classic style, but stretches and molds its lines to fit the American cruiser ethos. It’s hard to find any aesthetic fault in the R 18.

The R 18 draws from the com­pany’s own classic style, but stretches and molds its lines to fit the American cruiser ethos.

The Softail Slim is also a beautifully styled bike, and it’s hard to beat a V-twin when it comes to the cruiser design. Still, when parked next to the R 18, little pieces that wouldn’t normally attract much attention, exhaust clamps and the like, suddenly jumped out. Harley-Davidson has always been known for its fit and finish and previously set the standard in this cate­gory, but the R 18 raises that bar higher. And perhaps it should, since our First Edition also costs $4,721 more than the Slim.

Riding the bikes back to back, we found the Harley-Davidson felt like a Ducati Monster compared to the BMW. The Slim was relatively light and agile, tipping into and pulling out of turns more easily and with more grace. Limited cornering clearance on the R 18 reminds you of what you already know: If you’re excited, you probably need to slow down. There is pleasure to be found in the R 18′s ride, but through scenery, not speed. Find a favorite road and take the time to enjoy it. You can get a swift flow going, but rushing is never rewarded on the R18.

Limited suspension travel and low ride height, mainstays of the cruiser riding experience, are found on both models. Solo seats come standard on each, though the R 18′s is stiffer and less forgiving. Rear suspension travel is within a tenth of an inch, but you wouldn’t know it by riding the bikes. Spending a full Softail tank of gas on the highway may have you tired from fighting the wind, but the same distance on the R 18 exhausts riders through being on constant alert for bumps and shifting their weight to the footpegs to avoid compacting their tailbones. The BMW just rides harder out back.

This comparison proved to be one of cultural significance, style, and emotional response more than engine performance, as the Slim outperformed the R 18 in nearly every test category. While the BMW produced more horsepower and torque on the Cycle World dyno, much of the disparity in our performance testing numbers can be attributed to the bikes’ 124-pound weight difference. The Slim was 0.69 second faster in the quarter-mile, 0.54 second faster to 30 mph, and 1.77 seconds faster to 100 mph. Only in brake testing did the R 18 surpass the Softail, stopping 2.89 feet shorter than the Slim from 60 mph.

Much in the way that a recent religious convert might feel the need to extol the fundamentals of their newfound belief more than someone born into the faith, BMW has leaned into everything that makes a cruiser a cruiser. The R 18 is longer, heavier, and vibrates more than the competition. But it is also still remarkably BMW, with considerations like a reverse drive, adaptive headlight, heated grips, and the cutesy Rock and Roll ride modes. Herr Miritsch said, “It should be emotional, but without disturbing or even distracting the rider at any time.” And while the bike does succeed in delivering an emotional ride, there are undoubtedly disturbances and distractions if you get it even slightly outside of its designated comfort zone. The end result is something of an uneasy compromise, checking the cruiser boxes while hitting some BMW key points. It feels like Michael Jordan playing baseball.

As a brand that has no real custom or cruiser heritage, BMW has managed to use its own history to create an endearing narrative around this new motorcycle. By adding a thicker seat and vibration-mitigating components at the footpegs, seat, and risers, the pleasure of use on the R 18 could be greatly expanded, its potential more thoroughly realized. The Softail Slim echoes the glory of Harley-Davidson’s century-plus of cruiser motorcycle manufacturing, and other specified Harley-Davidson models are available with the same engine and chassis, tuned to deliver a different experience with each model. BMW brings a solid contender to the fight, but for now, it’s all Harley-Davidsons on the Route 66 postcards.

		2021 BMW R 18 First Edition	2021 Harley-Davidson Softail Slim
ENGINE	Type	Air-/oil-cooled, horizontally opposed twin	45-degree Milwaukee-Eight 107 V-twin
	Displacement	1,802cc	1,745cc
	Bore X Stroke	107.1 x 100.0mm	100.0 x 111.1mm
	Compression Ratio	9.6:1	10.0:1
	Valve Train	OHV, 4 valves/cylinder	OHV, 4 valves/cylinder
	Induction	(2) 48mm throttle bodies	(1) 55mm throttle body
	Trans. / Final Drive	6-speed/shaft drive	6-speed/belt
CHASSIS	Front Suspension	49mm telescopic fork, nonadjustable; 4.7 in. travel	49mm telescopic fork, nonadjustable; 5.1 in. travel
	Rear Suspension	Steel swingarm w/ central shock strut, spring preload adjustable; 3.5 in. travel	Coilover monoshock, spring preload adjustable; 3.4 in. travel
	Front Tire	Bridgestone Battlecruise H50 120/70R-19	Dunlop D401 130/90B-16
	Rear Tire	Bridgestone Battlecruise H50 180/65B-16	Dunlop D401 150/80B-16
	Rake / Trail	32.7°/5.9 in.	30.0°/5.8 in.
	Wheelbase	68.1 in.	64.2 in.
	Seat Height	27.2 in.	26.4 in.
	Fuel Capacity	4.2 gal.	5.0 gal.
	Dry Weight	764 lb.	642 lb.
CW MEASURED PERFORMANCE	Horsepower	81.3 hp @ 4,800 rpm	73.7 hp @ 4,900 rpm
	Torque	103.1 lb.-ft. @ 2,900 rpm	98.4 lb.-ft. @ 2,800 rpm
	Fuel Consumption	35.9 mpg	36.7 mpg
	Quarter-mile	13.82 sec. @ 100.82 mph	13.13 sec. @ 104.13 mph
	0-30	2.37 sec.	1.83 sec.
	0-60	4.96 sec.	4.39 sec.
	0-100	13.50 sec.	11.73 sec.
	Top-gear Roll-on 40-60	4.44 sec.	3.93 sec
	Top-gear Roll-on 60-80	4.99 sec.	4.23 sec.
	Braking 30-0	34.0 ft.	35.8 ft.
	Braking 60-0	135.5 ft.	138.4 ft.
	Price	$22,265	$15,999 ($17,544 as tested)