Of all of the bikes updated in the 2018 Harley-Davidson Softail cruiser line, the Fat Bob--formerly a Dyna rubber-engine-mount model with twin shocks--stretches brand DNA the most. The Fat Bob is no longer sort of a chunky-tire, muscled-up step-brother to the Street Bob. The Fat Bob now has an even stronger identity of its own, and that identity is fierce.

Harley-Davidson used words like “Battlestar Galactica” and “zombie apocalypse” to describe the inspiration for the Fat Bob, and the designers wanted the look to convey agility and the attitude that the bike wanted to eat whatever asphalt or potholes were in its path. It is the highest performance bike in the 2018 Harley-Davidson cruiser line.

As with the rest of the new 2018 Softail model lineup, the Breakout now features a new version of the four-valve-per-cylinder Milwaukee-Eight 107ci V-twin with dual counterbalancers to cancel primary vibration. This allows the engine to be rigid mounted in the frame, which increases chassis stiffness for improved handling. Harley-Davidson claims the 107ci Milwaukee-Eight makes the new bikes 10 percent faster from 0-60 than the High Output Twin Cam 103 engine used previously.

harley-davidson, fat bob, softail
The 2018 Harley-Davidson Fat Bob features a new version of the Milwaukee Eight 107 engine which now has dual counter balancers to help cancel out primary vibrations.Harley-Davidson

The mild-steel tubular frame has also been redesigned and is 65 percent stiffer than the outgoing Softail frame. This new frame has 50 percent fewer component parts, 22 percent fewer welds and, with the solid-mount engine, makes for an overall 34 percent more rigid chassis. This new frame (along with other changes) help reduce the weight of the Fat Bob by 33 pounds for 2018.

The Showa Dual Bending Valve (SDBV) fork Harley-Davidson introduced to much praise on the FL touring line last year is now applied to 2018 Softail motorcycles. In the case of the Fat Bob, however, a sportier inverted 43mm version is used, rake set at a relatively quick-steering 28 degrees. The Showa fork reduces weight and provides linear damping characteristics to provide a more comfortable, better controlled ride and improved handling.

At the rear, Harley ditched the Dyna twin shocks in favor of a single under-seat coil-over unit shared by all new Softails. In this new Softail design, shock action is conventional--that is the rear wheel hits a bump and compresses the shock--whereas the old Softail design extended the shocks when the wheel hit a bump. The new design improves performance by offering increased wheel travel, improved damping and a larger range of spring preload adjustment, while still maintaining the hardtail look brought about by the “shockless” rear frame triangle. The Fat Bob gets an external knob for spring preload adjustment.

Harley suggests the Fat Bob’s performance exceeds even that of the 2017 Dyna Low Rider S--largely considered the best Dyna ever made--all thanks to things like dual disc front brakes, its powerful new motor, redesigned chassis and suspension, and a new 2-into-1-into-2 performance exhaust.

harley-davidson, fat bob, softail, fuel tank
Harley-Davidson Fat Bob Fuel TankHarley-Davidson

The fuel tank has been reshaped, coming in almost a gallon and a half smaller at 3.6 gallons. Claimed wet weight with a full tank of gas is 675 pounds. Tires are the largest, most aggressive offered by Harley-Davidson, with a 130mm-wide front and a 150mm-wide rear, rolling on 16-inch cast wheels.

The 2018 Harley-Davidson Fat Bob starts at $16,999 in vivid black, and goes up to $17,399 for other paint schemes. ABS is a $795 option.

2018 Harley-Davidson Fat Bob
Engine: New Milwaukee-Eight 107
Displacement: 107 cu. in./1746cc
Transmission: 6-Speed Cruise Drive
Torque: 110 lb.-ft. @ 3000 RPM
Fuel Economy: 47 mpg
Overall Length: 92.1 in.
Overall Width: 37.8 in.
Seat Height: 27.7 in.
Ground Clearance: 4.7 in.
Lean Angle (left/right): 31/32 deg.
Wheelbase: 63.6 in.
Wheel Size Front: 16 in.
Wheel Size Rear: 16 in.
Fuel Capacity: 3.5 gal.
Running Weight: 675 lb.
GVWR: 1160 lb.