Build Your Gravel Bike Your Way
The X-LAB GT8 Frameset is a starting point for a custom gravel bike built around the roads you ride and the components you prefer. Its carbon frame, gravel-focused geometry and room for wider tyres make it suitable for everything from fast mixed-surface rides to longer adventures on back roads.
Finished in Slipstream Blue/Silver, the GT8 gives you the freedom to choose your drivetrain, wheels and finishing kit instead of adapting a complete bike after purchase.
Made for Mixed-Surface Riding
The GT8 uses a carbon frame with geometry designed to feel settled on gravel while remaining responsive on sealed roads. A 435 mm chainstay length and 80 mm bottom-bracket drop provide the basis for a stable riding position when the surface becomes loose or uneven.
It is a useful platform for a fast gravel build, a comfortable all-road bike or a lightweight adventure setup. Your choice of tyres, wheels and gearing can be tailored to the type of riding you do most.
Room for Wider Tyres
The GT8 platform has a stated maximum tyre clearance of 55 mm. That gives you room to choose a wider tyre for added comfort and grip on rougher gravel roads, or a quicker-rolling tyre for rides that spend more time on the seal.
Actual clearance depends on the tyre and rim combination. Leave appropriate space for mud and debris, and check the measured tyre width before fitting tyres close to the maximum.
Storage and Mounting Points
The GT8 platform includes in-frame storage and accessory mounting points on the frame and fork. These provide options for carrying bottles, tools and other essentials on longer rides.
Before planning a loaded build, check the fit of your chosen bags or accessories and confirm the applicable frame and fork load limits.
Plan the Build Around Your Fit
A frameset gives you control over the finished bike, but choosing compatible parts and the right position matters. We can help you compare the GT8’s stack and reach with your current bike and plan the cockpit, gearing and wheel setup for your riding.
The size-specific component dimensions below are supplied as a reference. Please confirm which cockpit and seatpost parts are included with the NZ-supplied frameset before ordering.
Key Features
- X-LAB GT8 carbon gravel frameset
- Slipstream Blue/Silver finish
- Gravel-focused geometry
- Stated maximum tyre clearance of 55 mm
- In-frame storage
- Accessory mounting points on the frame and fork
- 435 mm chainstay length across the size range
- 80 mm bottom-bracket drop across the size range
- Listed in sizes S, M, L and XL
- Suitable starting point for a custom gravel or all-road build
What Is Included?
This is a frameset, not a complete bicycle. Wheels, tyres, drivetrain, brakes, saddle and pedals are required to complete the build.
Please contact Chain Reaction before ordering to confirm the exact NZ-supplied package, including the fork, seatpost, cockpit, headset, axles, derailleur hanger and any small parts.
Who Is It For?
- Riders planning a custom gravel bike
- Mixed-surface and all-road riding
- Long gravel rides and events
- Riders wanting room for wider tyres
- Lightweight adventure and bikepacking builds
- Riders who already have a preferred wheelset or groupset
Our Thoughts
The GT8 is a good starting point if you know how you want your gravel bike to ride. You can keep it quick with a lighter wheel and tyre setup or choose wider tyres and carrying options for rougher back roads and longer days out.
Before choosing parts, we would confirm the frame size and intended riding position. The right handlebar width, stem length and gearing will make the finished bike much more enjoyable than simply picking the lightest components.
Technical Specifications
- Frame: X-LAB GT8 carbon gravel frame
- Finish: Slipstream Blue/Silver
- Stated maximum tyre clearance: 55 mm
- Storage: Integrated in-frame storage
- Mounts: Accessory mounting points on frame and fork
- Listed sizes: S, M, L and XL
- Included components: Contact Chain Reaction to confirm the NZ-supplied package
Size Guide
The Slipstream frameset is listed in sizes S through XL. Rider height is only a starting point; body proportions, flexibility and preferred riding position all affect the best size.
Contact Chain Reaction for help comparing the geometry with your current bike or planning your preferred gravel position.
Component Dimensions
The dimensions below are supplied by X-LAB as size-specific references. Inclusion of these parts with the frameset should be confirmed before ordering.
| Size | Stem | Handlebar | Seatpost |
|---|---|---|---|
| S | 70 mm | 370/430 mm | 300 mm |
| M | 80 mm | 390/450 mm | 350 mm |
| L | 90 mm | 390/450 mm | 350 mm |
| XL | 100 mm | 410/470 mm | 350 mm |
Geometry
All lengths are in millimetres unless otherwise stated.
| Measurement | S | M | L | XL |
|---|---|---|---|---|
| Seat-tube length | 447 | 471 | 491 | 532 |
| Top-tube length | 525 | 547 | 566 | 585 |
| Head-tube length | 100 | 120 | 140 | 165 |
| Seat-tube angle | 75° | 74° | 74° | 73° |
| Head-tube angle | 70° | 71° | 71° | 71° |
| Chainstay length | 435 | 435 | 435 | 435 |
| Wheelbase | 1,032 | 1,031 | 1,046 | 1,061 |
| Fork offset | 55 | 50 | 50 | 50 |
| Bottom-bracket drop | 80 | 80 | 80 | 80 |
| Stack | 540 | 565 | 584 | 607 |
| Reach | 379 | 384 | 392 | 399 |
| Front centre | 610 | 609 | 624 | 638 |
| Trail | 72 | 70 | 70 | 70 |
| Standover height | 730 | 755 | 773 | 807 |
Why Buy from Chain Reaction?
- Custom build and component compatibility advice
- Expert gravel-bike sizing and setup advice
- Professional workshop for assembly and setup
- Help choosing wheels, tyres, gearing and cockpit components
- Practical advice for planning an adventure or bikepacking build
- Finance options available
Visit Chain Reaction at 4/218 Moorhouse Avenue, Christchurch to discuss your build. There are more than 200 free car parks on-site.
Specifications and included parts may change without notice. Contact us to confirm the frameset package and component compatibility before ordering.
