▷ 'GT-B' – Harley-Davidson Softail Breakout by Thunderbike

The GT-B is a radically customized Harley-Davidson Softail Breakout, built by Thunderbike, blending modern performance engineering with an unmistakable custom drag-bike stance.

Designed to push visual limits while remaining fully rideable, this build represents Thunderbike’s signature approach: precision, balance, and uncompromising style.

GT Wheels and Extreme Tire Setup

At the core of the GT-B’s aggressive look are the Thunderbike GT wheels, paired with a muscular tire configuration. The rear features a Metzeler Cruisetec 260/35VR21, delivering massive road presence and outstanding grip, while the front runs a Metzeler ME888F 130/60B23, ensuring stability and confident handling. This wheel and tire combination defines the bike’s stretched and powerful silhouette.

Single-Side Swingarm and Drivetrain Upgrades

The Thunderbike single-side swingarm kit (21″ aluminum) transforms the rear end into a true showpiece, exposing the wheel while enhancing structural rigidity. Power is transferred via a Thunderbike 1″ heavy-duty belt and a Grand Prix single-side pulley, engineered for durability and smooth performance under load.

Braking and Suspension Performance

Stopping power is upgraded with a Thunderbike Vegas floated brake disc (340 mm), combined with a brake caliper adapter (300→340 mm) for precise braking response. The front end is visually lowered using a Thunderbike tele fork lowering kit, reinforcing the bike’s low and aggressive stance.

Ride height and comfort are controlled through a Thunderbike air ride suspension kit, allowing the GT-B to sit slammed when parked and rise to optimal riding height on demand.

Bodywork and Aerodynamic Details

The bodywork is defined by clean, sharp lines. A Thunderbike GFK front fender (21″/23″) perfectly frames the oversized front wheel, while the GP-style long chin fairing adds a performance-inspired racing touch. Together, these elements enhance both aerodynamics and visual flow.

Controls, Ergonomics, and Rider Interface

The riding position is optimized with a Thunderbike forward control kit, including black mounting hardware, V-Tech rider footpegs, and an aluminum shift peg. A flat riser kit (2″) keeps the handlebar low and aggressive, while Thunderbike Base Rubber grips ensure comfort and control.

Rear visibility and minimalism are achieved using Motogadget mo.view Sport 150 mirrors in black, combined with Stripe LED turn signals neatly integrated into the design.

Intake, Covers, and Fine Details

Performance and aesthetics meet at the intake with the Thunderbike Oval Torque airbox cover and airbox kit, complemented by an EFI cover with manometer bracket in black wrinkle finish. Additional CNC-machined details include the Torque timer cover, axle covers for the swingarm and front axle, and multiple Thunderbike topper components that elevate the overall finish.

Clean Rear End and Lighting Solution

The rear of the GT-B remains exceptionally clean thanks to a Thunderbike inside license plate frame, complete with integrated lighting and reflector. This solution preserves legality while maintaining the bike’s minimalist custom appearance.

A Modern Custom Statement

The GT-B Thunderbike Breakout is more than a visual statement—it’s a carefully engineered custom motorcycle that combines aggressive design, premium components, and everyday usability. From its massive wheels and single-side swingarm to its air suspension and precision-machined details, every element reflects Thunderbike’s commitment to high-end custom craftsmanship.