AB-st Gravel Bike – GRX


When the adventure starts at your front door your bike needs to be ready for anything and everything and our complete AB-st with Shimano’s GRX Drivetrain will take you through the badlands and back. With the main focus being to create our best-yet gravel mashing machine we went to painstaking lengths to make the AB-st equally viable as a multi-day bikepacking rig, mainly through the seemingly endless mounting options, extra wide tire clearance and the cushy, rake-adjustable front forks. Not after a complete? Get your AB-st Frameset here. Please note: Due to supply chain issues we may need to make minor adjustments to the build kit. We’ll communicate any issues with you before moving forward with the build.

FRAME 4130 LY Select Chromoly Steel Frame with Internal Routing
FRONT FORK Carbon Adventure Fork with Internal Routing and adjustable rake.

STEM Easton EA50 3D Forged
BRAKES Shimano GRX RX810 Hydraulic Disc Brake
SADDLE BBB Spectrum 145mm

RIMS Easton AR25 Novatec
HUBS Novatech sealed bearings
TIRES WTB VNine Line TCS 29 x 2.25

CRANKS Easton EA90 Cranks

Frameset Specs

Designed to take on whatever terrain you throw at, be it your daily commute, exploring your local trails, or camping in the bush the AB-st is up for the task. Built with 4130 LY Select Chromoly Steel and our carbon ADV fork, The AB-st offers a stable, confident, yet playful feel. The frameset, front forks and the top tube are well equipped with mounting options, allowing you to attach all the accessories you need and where you want them.  With clearance for up to 29×2.25” tires and a long wheelbase, this bike is designed with bikepacking and getting RAD in mind.


4130 LY Select Chromoly Steel Frame with Internal Routing
Carbon Adventure Fork with Internal Routing
Front Fork Rake Adjustable to 47mm or 52mm
Thru Axels Front and Rear (12×100 F, 12×142 R)
FSA Integrated Headset
Weight of Medium is 6.25 Lbs
Available Sizing – S, M, L, XL

Included with Frameset – Frame, Fork, FSA Headset, Seatpost Clamp and Front And Rear Axels
Limited to 100

AB-st GRX Gravel Bike Build Kit

Shimano GRX Shifters

– Gravel Inspired Lever and Bracket Ergonomics.
– Anti-Slip Brake Lever.
– Greater Mixed-Terrain Control.
– Same Light Shifting Operation as Top Tier Systems.

Shimano GR600 Derailleur

– Adjustable Chain Stabilizer Prevents Chain Slapping and Drops
– Toggle Clutch On/Off To Match The Terrain
– Switch Stabilizer On/Off To Match The Terrain
– Gravel-Tuned Clutch Tension
– Silent And Uninterrupted Rear Shifting on Rough Terrain

Shimano GRX Calipers

– Excellent Heat Dissipation.
– Flat Mount And Anti-Mud Specification.
– Convenient Tool Access.
– Easy And Clean Bleeding System.

WTB VNine Line TCS 29 x 2.25 Tires

– Lightweight design specifically for cross-country racing.
– Short knob height increases rolling efficiency.
– Hard centerline tread compound matched to soft side knobs coat a supple
– Gram-conscious casing designed to be compliant while still trail worthy.

Easton AR25 Novatec

– 25mm internal width.
– EA50 Alloy.
– Offset nipple bed for improved spoke tension balance and wheel strength/stiffness.
– Tubeless ready with strong tire retention bead.

Easton EA50 AX

– The same MCD drop technology as our top of the line road bars.
– Flared to 16 degrees for comfort in the drops and control on gnarly terrain or long gravel assaults.

Easton EA50

– Durable EA50 aluminum alloy shaft .
– Easy-to-adjust two-bolt clamp.
– Forged aluminum clamps offer rock-solid stability.
– 10-millimeters of offset will accommodate any bike fit.

Easton EA50

– Easton delivers quality and sound engineering all the way down to this family of entry-level stems.
– EA50 Alloy.



Recommended Rider Height 5’3″-5’6″ 5’6″-5’9″ 5’9″-6’2″ 6’2″-6’6″
Seat Tube C-T 450mm 480mm 510mm 540mm
Seat Tube Angle 74º 74º 74º 74º
Head Tube Length 150mm 170mm 190mm 210mm
Head Tube Angle 70°  70°  70°  70°
Top Tube Horizontal Length 535mm 565mm 595mm 615mm
Stack 569mm 588mm 607mm 626mm
Reach 391mm 415mm 440mm 455mm
Fork length A-C 398mm 398mm 398mm 398mm
Chainstay Length 430mm 430mm 430mm 430mm
BB Drop 72mm 72mm 72mm 72mm
Wheelbase 1046mm 1077mm 1108mm 1130mm

AB-st GRX In Action

Got some questions? Let's Talk