ROCKBROS Gravis 20inch Folding Bike 9-Speed Hydraulic Disc Brake 4130 Steel LUG

$ 686.4

Department: Unisex Adults Frame Size: 20 in Item Weight: 11.8 kg Handlebar Type: Flat Bar Folding Stem: One-Piece Forged Aluminum Folding Stem Shifter: MicroShift Advent 1 X 9S gtin13: Does not apply Tire Type: Tubeless Tires Country of Origin: China Brake System: 160mm Front / 140mm Rear Model Year: 2026 Item Length: 150cm Brake Type: Disc Brake - Hydraulic Tires: 406 x 1.95 inch CST Mountain Bike Tires Model: ROCKBROS Gravis Frame: 4130 Cr-Mo Steel Frame with LUG Construction EAN: Does not apply Brakes: Dual-Piston CNC Machined Aluminum Hydraulic Disc Brakes Custom-Built: No Vintage: No Brand: ROCKBROS Number of Speeds: 9 Speed Suspension Type: No Suspension Crankset: Forged Aluminum Lightweight 44T Single Chainring Cable Housing: LUG Housing Manufacturer Warranty: 3 Years Wheelset: Aluminum Hub + Double-Wall Sleeve-Joint Aluminum Rim, 24 Spokes Cockpit: 6061-T6 Forged Handlebar & Seatpost Bike Type: Folding Bike Shifter Style: Trigger Shifter UPC: Does not apply Drivetrain: MicroSHIFT ADVENT 9-Speed Gear Change Mechanism: Derailleur Gears Wheel Size: 20 in Frame & Fork: 4130 High-Strength Steel Cassette: Lightweight 9-Speed 11-34T Cassette Features: Adjustable Seat, Lightweight, Quick-release seatpost clamp

Description

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. Origin LUG housing craft originated in Europe, with brands like Colnago, Bianchi, Cinelli, Pinarello, and De Rosa known for their LUG and steel frames, representing the peak of steel frame craftsmanship. In the U.S., Rivendell is famed for silver brazed LUGs and retro geometry. In Japan, TOEI, and in the UK, Mercian, are renowned for hand-carved LUGs and custom paint, making them highly coveted by collectors. Today, many brands are reviving these classic designs, solidifying LUGs as a symbol of high-end craftsmanship. LUG Housing Craft Compared to direct welding, the LUG housing process makes it easier to maintain consistency during frame production and allows for the use of lightweight steel tubes. LUG housing offers a larger contact area and precise angle control, making the frame connections more solid and reliable. 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.

  1. Good helmet at a good price! But my hat is off to the seller, shipping took a little longer than I expected and when I got a package meant for a neighbor I thought I was being scammed and sent a rather impolite message to the seller. They calmly responded and I thank them for their professionalism and apologize for my lack of tact!

    Ahsan Shafiq
  2. Excellent! Super Duper Fast Shipping. Excellent communication. They told me that the item that I paid for is out of stock and they sent me a free gift and told me to please wait till they have the item in stock again. I waited and today I got my item. They are Great Sellers. I Highly Recommend them. AAAAAAAAAAA++++++++++++

    Fariba8c4ff8
  3. Great Seller. Great Communication. Exactly As Described. Lightning Fast Shipping. Excellent Packaging. High Quality Item At A Great Price. Will Be A Return Customer. A++++++

    Ravinder Kaur