Of course. Here is a full article about the 2012–2017 Harley-Davidson Dyna Twin Cam 103 (FXDB Street Bob), written in the requested style and format.
The 2012–2017 Harley-Davidson Dyna Twin Cam 103 (FXDB Street Bob) represents a significant era for one of Harley-Davidson’s most popular factory bobbers. Positioned within the Dyna family, known for its traditional exposed dual rear shock absorbers and Big Twin engine, the Street Bob was lauded for its minimalist, aggressive styling and its role as a “blank canvas” for customization. This specific period is defined by the standardization of the larger Twin Cam 103 engine, which provided a notable performance increase over its predecessor and marked the final evolution of the celebrated Dyna platform before its discontinuation after the 2017 model year.
History and Development
The Harley-Davidson Dyna chassis was first introduced in the early 1990s, establishing itself as the company’s performance-oriented Big Twin platform. The FXDB Street Bob model was launched in 2006, immediately capturing attention with its stripped-down, post-war “bobber” aesthetic. It featured signature design cues such as mini-ape hanger handlebars, a solo seat, a “bobbed” rear fender, and blacked-out components, including the rims and powertrain.
The most critical update for this model generation arrived in 2012 when Harley-Davidson made the Twin Cam 103 engine standard across most of the Dyna line, including the Street Bob. This move elevated the model from a capable cruiser to a machine with substantially more road presence and authority. The 2012–2017 production run solidified the Street Bob’s identity as a raw, rider-focused motorcycle before the entire Dyna family was merged into the redesigned Softail platform in 2018.
Transition from the Twin Cam 96
The primary difference between the 2012–2017 Street Bob and its immediate predecessor (2007–2011 models) was the engine. The earlier models were equipped with the Harley-Davidson Twin Cam 96, which displaces 96 cubic inches (1,584 cc). While a reliable and well-regarded powertrain, the market’s demand for more power led to the upgrade.
The Twin Cam 103, displacing 103 cubic inches (1,690 cc), offered a tangible increase in performance. The larger displacement, achieved through a larger bore, resulted in a significant boost in torque—the hallmark of a Harley-Davidson V-Twin. This translated to stronger acceleration from a stop, more responsive roll-on power for highway passing, and a more robust feel throughout the RPM range. While horsepower figures saw a modest increase, the accessible, low-end torque is what riders immediately noticed, making the 103-powered Street Bob a more engaging and potent machine without sacrificing the classic character of the Dyna platform.
Design and Features of the 2012–2017 Harley-Davidson Dyna Twin Cam 103 Street Bob
The identity of the FXDB Street Bob during this period was defined by a combination of minimalist styling and mechanical substance.
Styling: The motorcycle maintained its core bobber DNA. Key visual elements included black steel-laced wheels, a blacked-out powertrain with polished fin edges, a Fat Bob-style fuel tank with a console-mounted ignition, and a chopped rear fender. The solo seat reinforced its stripped-back, lone-wolf image, though passenger accommodations were available as accessories. The mini-ape hangers placed the rider in an aggressive, upright posture.
Chassis: The Street Bob was built on the classic Dyna frame, which is distinguished by its rubber-mounted engine that isolates the rider from the V-Twin’s vibrations at idle and on the road. The frame’s geometry and the presence of exposed, coil-over dual rear shocks contributed to the Dyna’s reputation as one of the best-handling Big Twin platforms of its time. Mid-mounted foot controls provided a more connected and assertive riding position compared to forward controls found on other cruisers.
Powertrain:** At the heart of the bike was the air-cooled Twin Cam 103 V-Twin engine, paired with the six-speed Cruise Drive transmission. This combination delivered strong, reliable performance with the classic Harley-Davidson sound and feel. The transmission provided smooth shifting and a tall sixth gear for relaxed highway cruising. Electronic Sequential Port Fuel Injection (ESPFI) ensured reliable starting and crisp throttle response.
End of an Era
The 2017 model year marked the end of the line for the entire Dyna platform, including the Street Bob. In a major strategic shift, Harley-Davidson consolidated its Big Twin cruiser lineup for 2018, integrating the Dyna models into a completely redesigned Softail chassis. The new Softail frame featured a hidden “monoshock” rear suspension, retiring the iconic dual-shock design that had defined the Dyna for over two decades. As a result, the 2012–2017 FXDB Street Bob is now regarded as the final and most refined iteration of this classic Harley-Davidson model.
Specifications
| General | |
| Brand | Harley-Davidson |
| Model | Dyna |
| Model Class | Street Bob (FXDB) |
| Model Year | 2012–2017 |
| Type | Cruiser / Bobber |
| Maximum mass (GVWR) | 1,085 lb. (492 kg) |
| Maximum passengers | 1 (Standard), 2 (Optional) |
| Performance | |
| Max. power | ~75 Hp (56 Kw) / 5010 RPM (Estimated) |
| Max. torque | 98.8 ft-lb (134 N•m) / 3000 RPM |
| Min. turn diameter | ~20 ft (6.1 m) |
| Top designed speed | ~115 mph (185 km/h) |
| Size | |
| Length | 94.3 in. (2395 mm) |
| Width | 35.2 in. (895 mm) |
| Height | 50.2 in. (1275 mm) |
| Wheelbase | 64.2 in. (1630 mm) |
| Seat height (laden) | 25.5 in. (648 mm) |
| Ground clearance | 4.7 in. (120 mm) |
| Curb weight | 670 lb. (304 kg) |
| Engine | |
| Type | Air-cooled, Twin Cam 103™, 45° V-Twin, Four Stroke |
| Displacement | 103.1 cu in (1690 cc) |
| Bore × Stroke | 3.87 in. × 4.37 in. (98.4 mm × 111.1 mm) |
| Compression ratio | 9.6:1 |
| Starting system | Electric starter |
| Fuel supplying system | Electronic Sequential Port Fuel Injection (ESPFI) |
| Ignition control system | ECU Ignition |
| Lubricating system | Dry-sump |
| Oil capacity | 3 qt (2.8 L) |
| Engine oil type | SAE 20W-50 Harley-Davidson H-D 360 Motorcycle Oil |
| Idle speed | 1000 RPM ± 50 RPM |
| Transmission | |
| Transmission type | 6-speed Cruise Drive®, manual |
| Clutch type | Wet, multi-disc, manual |
| Driving system | Belt drive |
| Primary reduction ratio | 1.737 |
| Final reduction ratio | 2.125 |
| Gear ratio | 1st: 3.337; 2nd: 2.313; 3rd: 1.719; 4th: 1.391; 5th: 1.185; 6th: 1.000 |
| Chassis | |
| Tire size | Front: 100/90B19 57H; Rear: 160/70B17 73V |
| Rim size | Front: 19 in.; Rear: 17 in. (Black Steel Laced) |
| Capacity of fuel tank | 4.7 gal (17.8 L) |
| Fuel consumption | Approx. 42 MPG (5.6 L / 100 km) |
| Electric | |
| Battery | 12V / 19 Ah |
| Headlight | Halogen 55W low beam, 60W high beam |
| Position Light | Integrated |
| Turning light | Incandescent |
| Tail light | Incandescent |
| Shock Absorbers | |
| Front | Telescopic fork |
| Front travel | 5 in (127 mm) |
| Rear | Dual coil-over shocks |
| Rear travel | 3.1 in (79 mm) |
| Rear spring preload | Adjustable |
