Marin Bikes | 2025 Four Corners Sora

📏Size Guide

Steel touring comfort and adventure-ready versatility for commuting, bikepacking, gravel exploration, and long-distance riding.

The Marin Four Corners Sora is a steel adventure touring bike built for riders who want comfort, cargo capability, and dependable all-road performance. Designed around Marin’s Series 1 CrMo steel frame with size-specific wheel sizing and stable touring geometry, the Four Corners Sora is equally at home on pavement, gravel roads, urban commutes, and loaded bikepacking adventures.

With plentiful rack and gear mounts, wide tire clearance, flared drop bars, and Shimano Sora 3x9-speed gearing, the Four Corners Sora delivers the versatility and durability needed for everyday riding and extended adventures alike.

Key Features

• Series 1 CrMo Steel Frame
Durable chromoly steel frame provides a smooth, compliant ride feel with long-distance comfort and touring durability.

• Adventure Touring Geometry
Stable geometry with size-specific wheel configurations improves comfort and handling across mixed terrain.

• Shimano Sora 3x9-Speed Drivetrain
Wide gear range offers climbing capability and versatility for loaded touring and varied terrain.

• Mechanical Disc Brakes
Reliable stopping power with easy maintenance for long-distance and all-weather riding.

• Extensive Mounting Capability
Rack, fender, bottle cage, and gear mounts support commuting, touring, and bikepacking setups.

• Size-Specific Wheel Platform
XS and Small sizes use 650B wheels for improved fit and handling, while Medium to XL use 700C wheels for efficiency and rollover performance.

• Wide Adventure Tires
40mm tires provide comfort, traction, and stability across pavement, gravel, and rough roads.

Technical Specifications

• Category
Adventure Touring Bike

• Discipline
Gravel / Road / Urban

• Frame
Series 1 CrMo, Biometric Geometry, Fender and Rack Mounts, Disc Mount

• Fork
Series 1 CrMo with Fender, Rack, and Bottle Cage Eyelets

• Bottom Bracket
Shimano

• Headset
FSA No.8D Sealed Cartridge Bearings

• Rear Derailleur
Shimano Sora 9-Speed

• Front Derailleur
Shimano Sora

• Shifters
Shimano Sora ST300 3x9-Speed

• Crankset
Shimano Sora FC3030, 50-39-30T

• Cassette
Shimano HG200 9-Speed, 11-34T

• Chain
KMC X9

• Brakes
Tektro Spyre-C Road Mechanical Disc Brakes

• Brake Rotors
160mm

• Wheelset
Marin Aluminum Double Wall Disc-Specific Rims

• Front Hub
Forged Aluminum Alloy, Disc, 32H

• Rear Hub
Forged Aluminum Alloy, Disc, 32H

• Tires
Vee Tire Co. GPVee, 650B/700C x 40mm

• Handlebar
Marin Butted Alloy Compact 16º Flared Drop Bar

• Stem
Marin 3D Forged Alloy

• Seatpost
Marin Alloy, 27.2mm

• Saddle
Marin MTB

• Pedals
Trekking Platform

• Color Options
Matte Black / Black / Chrome (#1A1A1A)
Gloss Turquoise / Purple / Chrome (#40E0D0)

Geometry

Suitable for gravel riding, touring, commuting, bikepacking, long-distance road riding, and mixed-terrain adventure use.