Gravis
A legacy reimagined. Innovation at its core.
Gravis is the perfect fusion of LUG's rich heritage and modern innovation. It combines the timeless elegance of LUG's classic craftsmanship with cutting-edge design and geometry, creating a folding bike that both honors tradition and leads the way into the future. While prioritizing lightweight and convenience, Gravis retains the warmth and depth of craftsmanship, allowing riders to still feel the elegant legacy of a century-old tradition.
Gravis-Steel Gravel Folding Bike
Your bike already arrives 95% built. We give you the tools. And simple instructions. No technical skills needed.
Free frame replacement for natural cracking under normal riding conditions (non-impact related).
LUG Craftsmanship: Where Tradition Meets Modern Design
LUG craftsmanship blends tradition with modernity, elevating folding bicycles with its intricate design and artistic details. It preserves the elegance of classic steel frames while adding a timeless charm to urban cycling.
4130 High-Strength Steel
Made from 4130 steel (C0.28-0.33%, Cr0.8-1.1%, Mo0.15-0.25%, balance Fe), this low-to-medium carbon chromium-molybdenum alloy offers excellent strength and toughness. After heat treatment, its yield strength reaches 560-700 MPa and tensile strength can go up to 700-900 MPa, combining high strength with great durability.
Compared to aluminum alloys like 6061-T6 (tensile strength around 310 MPa), 4130 steel offers more stable performance under impact and fatigue loads. Its excellent weldability and machinability make it an ideal material for complex and precise frame structures, especially for high-end road and folding bike frames.
Stopping Power: CNC Machined Aluminum Hydraulic Disc Brakes
Precision-engineered for optimal performance, these CNC-machined aluminum hydraulic disc brakes offer superior stopping power and control. Built for durability and responsiveness, they ensure smooth braking even in demanding conditions, providing a safe and reliable riding experience.
PURE HANDCRAFTED WELDING & BUILD
HIGHER STRENGTH
ACCOMMODATING SIZE
STABLE HANDLING
Bike Configuration List
Specification
| Item | Specification |
|---|---|
| Frame | 4130 Cr-Mo Steel Frame with LUG Construction |
| Folding Stem | One-Piece Forged Aluminum Folding Stem |
| Cockpit | 6061-T6 Forged Handlebar & Seatpost |
| Crankset | Forged Aluminum Lightweight 44T Single Chainring |
| Shifter | MicroShift Advent 1 X 9S |
| Cassette | Lightweight 9-Speed 11-34T |
| Brakes | Dual-Piston, Fully CNC-Machined Forged Aluminum Integrated Hydraulic Disc Brake System – 160mm Front / 140mm Rear |
| Wheelset | High-Polish Forged Aluminum Hub + Double-Wall Sleeve-Joint Aluminum Rim, 24 Spokes |
| Tires | 20*1.95 inch CST Mountain Bike Tires, Skinwall Color |
| Item | Specification |
|---|---|
| Frame | 4130 Cr-Mo Steel Frame with LUG Construction |
| Folding Stem | One-Piece Forged Aluminum Folding Stem |
| Cockpit | 6061-T6 Forged Handlebar & Seatpost |
| Crankset | Forged Aluminum Lightweight 44T Single Chainring |
| Shifter | MicroShift Advent 1 X 9S |
| Cassette | Lightweight 9-Speed 11-34T |
| Brakes | Dual-Piston, Fully CNC-Machined Forged Aluminum Integrated Hydraulic Disc Brake System – 160mm Front / 140mm Rear |
| Wheelset | High-Polish Forged Aluminum Hub + Double-Wall Sleeve-Joint Aluminum Rim, 24 Spokes |
| Tires | 20*1.95 inch CST Mountain Bike Tires, Skinwall Color |
Crafted for those who value artistry and innovation, the 4130 chromoly steel frame combines legendary toughness with advanced LUG copper brazing. Skilled artisans use molten copper to forge a bond of unmatched strength, leaving behind intricate, hand-crafted details that elevate the traditional road bike legacy to new heights in folding bike design.