BMW’s R 1250 GS is widely considered the ultimate adventure bike. Over the past 40 years, the GS series has sold 1.2 million units and set the benchmark for the large ADV market. From air-cooling to liquid-cooling, from variable-valve technology to active suspension, the 1250 GS’s innovative features keep it at the front of the pack. Despite numerous challenges from the likes of KTM and Ducati, the GS still reigns supreme.

Harley-Davidson's Pan America is the brand’s first crack at an adventure bike. For the past 118, the Motor Company has catered to the American market with cruisers and baggers (And, of course, small-displacement Italian two-strokes – ed.). So, when Harley developed its first full-size ADV, it knew it needed to measure up to Beemer’s segment-defining R 1250 GS. Marking a new technological height for the brand, Harley’s adventuring aspirations rest on the broad bodywork of the Pan America—but is it enough?

Will the newcomer supplant the GS’s sovereignty or will the Pan America bow to the Beemer’s rule? Can Harley-Davidson make an impact this late in the game? Will customers convert to the bar and shield for the Pan America? Answers to such questions require a thorough investigation of the two competitors, and for that, we turn to the spec sheets. Also, for the purposes of our showdown, we'll be comparing the base models of each Heavyweight ADV.

Overview

2021 BMW R 1250 GS
2021 Harley-Davidson Pan America
  2021 BMW R 1250 GS 2021 Harley-Davidson Pan America

Engine:

Air/liquid-cooled, DOHC, 1,254cc flat twin Liquid-cooled, DOHC, 1,252cc V-Twin
Bore And Stroke: 102.5 mm x 76 mm 105 mm x 72mm
Transmission: 6-speed 6-speed
Performance: 136 hp/ 105 lb-ft 150 hp/ 94 lb-ft
Weight (Wet):  549 pounds 534 pounds
Price: $17,995 $17,319

Toe To Toe

Harley and BMW both lean on brand heritage with their engine choices— a 60-degree V-twin for the Pan America and big-bore boxer for the Beemer. Both mills are packed with current technology like liquid-cooling, dual-overhead camshafts, and variable-valve timing. The two boast nearly identical capacities as well, with the 1250 GS’s 1,254cc volume marginally larger than Pan Am’s 1,252cc displacement. That’s where the similarities end, though.

With a 102.5 mm bore and 76 mm stroke, the Beemer’s boxer pumps out 136 horsepower and 105 lb-ft of torque. Harley’s Revolution Max favors a larger 105-mm bore and shorter 72-mm stroke, resulting in 150 horsepower and 94 lb-ft of torque. The Pan America’s 13.0:1 compression ratio also helps it gain a few ponies over the 1250 GS and its 12.5:1 compression ratio. While engine performance goes to the Harley on paper, both models deliver power with vastly different means.

BMW R 1250 GS - Dirt

Keeping things simple, Harley sticks with a conventional final chain drive. Sure, chains require frequent cleaning and lubing but they’re also easy to replace and work on. BMW’s GS series is synonymous with shaft drive and users benefit from maintenance-free riding as a result. However, repairing a shaft drive on the side of the road/trail isn’t in the cards for most GS pilots, so there are pros and cons to both setups.

On a similar note, the two models also require different valvetrain maintenance. With the Harley implementing hydraulic adjusters, the Pan Am’s valves are maintenance-free. Users will need to service the bike after the first 1,000 miles, however, and every 5,000 miles thereafter. The Beemer, on the other hand, requires its first service at 600 miles and relaxes regular maintenance intervals to every 6,000 miles. The GS does require valve adjustments every 12,000 miles, though.

Aside from the powertrain, the two full-size ADVs employ very different componentry as well. The Pan America features a 47mm USD fork paired with a linkage-mounted rear monoshock. The traditional setup nets 7.5 inches of travel at both ends, a figure only marginally outdone by the BMW’s 7.9 inches of rear travel. Despite the comparable results, the GS is known for its ultra-plush yet sweet-handling telelever front end, single-sided swingarm, and paralever rear suspension.

Double Duty

2021 Harley-Davidson Pan America - Double

While the R 1250 GS and Pan America tout off-road performance, the standard trims are more road-oriented. Both sport cast aluminum wheels—19 inches forward and 17 inches aft—shod in dual-sport rubber. Both brand’s offer wire-spoked wheels, but the upgrade definitely increases the MSRP. When it comes to stopping power, the two models feature four-piston calipers up front, providing more than enough stopping power on the pavement or in the dirt.

The real difference-maker is Beemer’s two-pot rear caliper over Harley’s single-piston unit. Helping to maximize that two-piston binder, BMW’s IMU-supported Integral ABS Pro caters to both street and dirt riding. Harley’s rider aids do include lean-sensitive ABS and traction control, but Beemer’s sophisticated system easily takes the cake. To access the electronic suite, users will turn to a 6.8 TFT dash on the Pan Am, which barely eclipses the GS’s 6.5 display. However, many riders would stand by BMW’s innovative interface over Harley’s Infotainment system.

In the cockpit, shorter adventurers will prefer the 1250 GS’s 33.5-inch seat height over the Harley’s 34.2-inch seat height. With a 5.2-gallon gas tank on the Beemer and a 5.6-gallon fuel cell on the PanAm, both will keep you in those perches for long stints. While the GS’s 59.6-inch wheelbase suits twisty roads over the Pan Am and its 62.2-inch wheelbase, the Hog’s 534-pound wet weight may be easier to handle than the GS’s 549-pound bulk.

Conclusion

2021 BMW R 1250 GS - Wheelie
2021 Harley-Davidson Pan America - Jump

At $17,319 for the Pan America and $17,995 for the R 1250 GS, both bikes are evenly matched—on paper. It’s clear that the Motor Company took a page out of the GS playbook, but the Pan Am will have to perform in the real world if it’s going to eat into BMW’s market share.

Of course, the two OEMs offer special edition models. Harley offers a Pan America Special and the Bavarians an R 1250 GS Adventure to boost the platform’s off-road capabilities. Both offer semi-active suspension and tubeless spoked wheels, but BMW overshadows the competition with a 7.9-gallon gas tank.

While the Pan America represents a new formidable foe for the R 1250 GS, only time will tell if Harley can carve out a niche within the large adventure bike segment. We’re just looking forward to seeing these two battle it out off the page and on the road, dirt, and showroom floor.

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