







Summer Sky 27–32g Race-Grade Ultralight Carbon Fiber Road Bike Thru-Axle Set – Custom Fit
Summer Sky Race-Grade Carbon Fiber Thru-Axle Set
Engineered for riders pursuing every possible gram of weight reduction, the Summer Sky Carbon Fiber Thru-Axle Set weighs approximately 27–32g per pair, depending on the dimensions required for each bicycle.
Compared with many standard factory thru-axles, this ultralight upgrade can reduce overall bike weight by 50g or more while maintaining the strength and reliability required for road cycling.
Each set is custom-made to match the axle dimensions and thread specifications of the selected frame.
Key Features
- Ultralight weight: approximately 27–32g per pair
- Saves approximately 50g or more compared with many original thru-axle sets
- Made from aerospace-grade black thermoplastic carbon fiber
- Patented high-strength construction
- Custom dimensions for different bicycle models
- Clean, minimalist race-inspired appearance
- Designed for high-performance road and racing bikes
- Includes one front and one rear thru-axle
Strength-Tested Construction
The Summer Sky carbon fiber thru-axle has undergone tensile, shear and torque testing:

- Ultimate tensile failure load: over 10,500N
- Factory tensile inspection standard: approximately 6,500N
- Ultimate shear load: over 10,000N
- Ultimate failure torque: over 25Nm
- Factory inspection torque: 15Nm
- Recommended installation torque: 8–12Nm
Compatibility
Custom-fit versions are available for selected road bike models from Specialized, Pinarello, Trek, Colnago, Giant, Cervélo, Cannondale, BMC, Bianchi, Factor, XDS, Quick, Winspace, Incolor, SAVA, Scott, Canyon and other brands.
Please select your exact bicycle model and generation from the available options.
Custom Orders
For bicycles not listed, please select “Other – Custom Front & Rear” and provide the following information:
- Bicycle brand, model and year
- Photos of the original front and rear thru-axles
- Effective axle length
- Thread diameter and pitch
- Threaded section length
Production time for custom thru-axle sets is approximately 7–10 business days.
Important Installation Information
Apply a small amount of suitable grease to the threads before installation. Always use a calibrated torque wrench and keep the installation torque between 8 and 12Nm.
Compatibility is determined by the exact axle dimensions and thread specifications—not only by the bicycle model name. If you are uncertain about your frame version, please contact us with photos before placing your order.
Weight varies according to axle length and specifications. Custom-made thru-axle sets require approximately 7–10 business days for production.
Compatibility Check: Due to the complexity of original equipment manufacturer (OEM) parts' models and batches, there may be instances where this product is incompatible.
Upon receiving this product, please compare it with the OEM specifications to ensure compatibility before installation.
Torque Specifications: Install this product strictly according to the torque values specified in the OEM parts manual.Installation Issues: If you encounter any discrepancies with the OEM specifications or face difficulties at the initial stage of installation, stop immediately and contact customer service for assistance with returns or exchanges.
No Forced Installation: Do not force installation under any circumstances.Liability: Any damages resulting from forced installation or unauthorized modifications of this product (or its components) will be the sole responsibility of the buyer.
All products are photographed to accurately represent the colors you will see upon receipt.
Due to differences in lighting, angles, or screen settings, slight color variations may occur.
The actual product should be considered the standard.For "colored" and "blue" products, the coloring process may result in uneven color distribution, making each product unique.
| S-PARTS Common Torque Reference Table for Bicycle Series | ||||||
| Ingredient | Component Name | Screw Name | Reference Torque | Anti-seize Usage | Medium-strength Threadlocker Usage | Special Requirements Remarks |
| Frame System | Handlebar Assembly | M4 Stem Fixing Screws | 4NM | Recommended | Consider with Caution | For special structure handlebar assemblies, please refer to the original manufacturer's recommended torque specifications. |
| M5 Stem Fixing Screws | 5NM | Recommended | Consider with Caution | |||
| M6 Stem Fixing Screws | 6-8NM | Recommended | Consider with Caution | |||
| M7 Handlebar Fixing Screws (Brompton) | 8-10NM | Recommended | Consider with Caution | |||
| M8 Stem Fixing Screws (BMX) | 8-10NM | Recommended | Consider with Caution | |||
| Headset | Headset Preload Screws (including M5/M6) | 4-6NM | Recommended | Not Recommended | ||
| Frame/Fork | M3 Fork Hose Clamp Screws | 1-2NM | Recommended | Not Recommended | For special structure seatpost clamps, please refer to the original manufacturer's recommended torque specifications. | |
| Water Bottle Cage Screws | 4NMM | Recommended | Not Recommended | |||
| M4 Derailleur Hanger Fixing Screws | 3-4NM | Recommended | Consider with Caution | |||
| M5 Derailleur Hanger Fixing Screws | 4-5NM | Recommended | Consider with Caution | |||
| M5 Front and Rear Rack Fixing Screws | 6-7NM | Recommended | Consider with Caution | |||
| M5 Seatpost Clamp Screw (Standard Clamp Design) | 6-7NM | Recommended | Not Recommended | |||
| Seatpost | M5 Saddle Rail Clamp Screws | 6-7NM | Recommended | Not Recommended | ||
| M6 Saddle Rail Clamp Screws | 7-9NM | Recommended | Not Recommended | |||
| M7 Saddle Rail Clamp Screws | 8-10NM | Recommended | Not Recommended | |||
| M6/M7 Single-Bolt Saddle Rail Clamp Screws | 10-12NM | Recommended | Not Recommended | |||
| M8 Single-Bolt Saddle Rail Clamp Screws (Brompton) | 12-14NM | Recommended | Not Recommended | |||
| Wheelset | M6 Quick-Release Wheelset Locking Screws | 6-8NM | Recommended | Not Recommended | ||
| M10 BMX Wheelset Locking Screws | Recommended | Not Recommended | ||||
| M14 BMX Wheelset Screws | Recommended | Not Recommended | ||||
| M9 Wheelset Locking Nuts | 12-14NM | Recommended | Not Recommended | |||
| M10 Wheelset Locking Nuts | 14-16NM | Recommended | Not Recommended | |||
| M12 Thru-Axle Bolt | 10-14NM | Recommended | Not Recommended | |||
| M14 Thru-Axle Bolt | 12-16NM | Recommended | Not Recommended | |||
| Brake System | Disc Rotor | Six-Bolt Disc Rotor Screws | 5-7NM | Consider with Caution | Recommended | Do not use anti-seize compounds or liquid thread lockers on screws related to the brake hydraulic system to avoid contaminating the hydraulic lines. |
| Center Lock Disc Rotor | 40NM | Recommended | Not Recommended | |||
| Brake Lever | M5 Brake Lever Fixing Screws | 5-7NM | Recommended | Not Recommended | ||
| M6 Brake Lever Fixing Screws | 6-8NM | Recommended | Not Recommended | |||
| Road Bike Shifter Fixing Nuts | 6-8NM | Recommended | Not Recommended | |||
| Brake Lever Bleed Port Screws | 2-3NM | Not Recommended | Recommended | |||
| Disc Brake Caliper | M6 Mountain Bike Caliper Fixing Screws | 9NM | Consider with Caution | Recommended | ||
| M5 Flat Mount Caliper Fixing Screws | 7NM | Consider with Caution | Not Recommended | |||
| M8 Hose Compression Fitting Screws | 6-7NM | Not Recommended | Not Recommended | |||
| M6 Caliper Body Screws | 12NM | Not Recommended | Not Recommended | |||
| M7 Caliper Body Screws | 14NM | Not Recommended | Not Recommended | |||
| M8 Caliper Body Screws | 14NM | Not Recommended | Not Recommended | |||
| M6 Caliper Banjo Screws | 12NM | Not Recommended | Not Recommended | |||
| Caliper Bleed Screws | 5-6NM | Not Recommended | Not Recommended | |||
| Brake Pad Pin | 3NM | Not Recommended | Not Recommended | |||
| C-Brake Caliper | Single Pivot Caliper Fixing Nut | 8NM | Not Recommended | Recommended | ||
| Dual Pivot Caliper Fixing Screws | 6-8NM | Consider with Caution | Consider with Caution | |||
| Brake Pad Fixing Screw Set | 7NM | Consider with Caution | Consider with Caution | |||
| Brake Pad Stop Screws | 3NM | Not Recommended | Not Recommended | |||
| Caliper Release Lever Screws | 3NM | Not Recommended | Not Recommended | |||
| Cable Anchor Screws | 5-7NM | Recommended | Not Recommended | |||
| Drivetrain System | Shifter | Shifter Clamp Bolt | 4-6NM | Recommended | Not Recommended | Do not use anti-seize compounds or liquid thread lockers on screws related to the brake hydraulic system to avoid contaminating the hydraulic lines. |
| Shifter Integration Bolt | 4-6NM | Recommended | Not Recommended | |||
| Shifter Top Cap Bolt (Shimano) | 4NM | Recommended | Not Recommended | |||
| Front Derailleur | Direct Mount Front Derailleur Fixing Bolt | 6-7NM | Recommended | Not Recommended | ||
| Front Derailleur Clamp Bolt | 5-7NM | Recommended | Not Recommended | |||
| Front Derailleur Cable Adjusting Bolt | 5-7NM | Recommended | Not Recommended | |||
| Rear Derailleur | Rear Derailleur Pivot | 10-12NM | Recommended | Not Recommended | ||
| UDH System Rear Derailleur Pivot | 25NM | Recommended | Not Recommended | |||
| M4 Pulley Bolt | 3NM | Consider with Caution | Consider with Caution | |||
| M5 Pulley Bolt | 4NM | Consider with Caution | Consider with Caution | |||
| M3 Rear Derailleur Lock Cover Bolt (Shimano) | 1.5NM | Not Recommended | Not Recommended | |||
| Rear Derailleur Cable Adjusting Bolt | 5-7NM | Recommended | Not Recommended | |||
| Crankset | Chainring Double-Sided Bolt | 6-8NM | Consider with Caution | Consider with Caution | ||
| Single Chainring Bolt | 8NM | Consider with Caution | Consider with Caution | |||
| M5 Crank Arm Bolt (SRAM 3-bolt) | 7NM | Consider with Caution | Consider with Caution | |||
| M4 Crank Arm Bolt (SRAM 8-bolt) | 4-5NM | Consider with Caution | Consider with Caution | |||
| M6 Crank Arm Fixing Bolt (Shimano) | 12-14NM | Consider with Caution | Consider with Caution | |||
| Crank Arm Cap (Shimano) | 2-4NM | Not Recommended | Not Recommended | |||
| Crank Arm Fixing Bolt (DUB) | 54NM | Recommended | Not Recommended | |||
| Crank Arm Fixing Bolt (Rotor) | 30-35NM | Recommended | Not Recommended | |||
| Crank Arm Fixing Bolt (EE) | 52NM | Recommended | Not Recommended | |||
| M8 Square Taper Crank Bolt | 30NM | Recommended | Not Recommended | |||
| Pedals | Pedal Axle | 25NM | Recommended | Not Recommended | ||
| Road Cleat Fixing Bolt (3-bolt) | 6-8NM | Not Recommended | Recommended | |||
| MTB Cleat Fixing Bolt (2-bolt) | 8NM | Not Recommended | Recommended | |||
