Onyx Carbon 20" 406x21i 28/36h Symetrical Pro Rim
Description
Onyx Carbon 20" 406x21 Symmetrical Pro Rim – 28/36H
Product Overview
The Onyx Carbon is a lightweight symmetrical carbon rim for 20" BMX wheels with centered spoke holes for front or rear wheel use. Available in 28 or 36-spoke drilling with 21mm internal width, it supports rim brakes and is tubeless-compatible with proper setup.
Key Features
- Carbon Construction – Lightweight material reduces rotational weight while maintaining rigidity and strength
- Symmetrical Design – Centered spoke holes allow use as front or rear wheel without disc brakes, increasing build flexibility
- 21mm Internal Width – Provides adequate tire support and compatibility with modern BMX tire profiles
- 406 ETRTO Sizing – Standard 20" BMX wheel size (ERD: 378mm) compatible with dedicated BMX tires
- Rim Brake Compatible – Works with rim brakes using carbon-safe pads to prevent overheating
- Tubeless Ready – Bead lock system supports tubeless setup with minimum 2 wraps of tubeless tape (additional items required)
- V-Brake Compatible – Can be used as rear rim with V-brake systems
- Spoke Hole Options – Available in 28 or 36-spoke drilling for different wheel-building requirements
Technical Specifications
- Material: Carbon
- Size: 20" (406 ETRTO)
- Internal width: 21mm
- ERD (Effective Rim Diameter): 378mm
- Spoke hole drilling: 28 or 36 holes, symmetrical/centered
- Maximum spoke tension: 115 kgf
- Maximum tire pressure: 100 PSI
- Tubeless compatible: Yes (requires tubeless tape, valve, sealant, and liquid sealer)
- Rim brake compatible: Yes (carbon-safe pads required)
- Weight: Reduced versus aluminum alternatives
Build Requirements & Compatibility
- Spoke Compatibility – Use only butted or bladed steel spokes; straight gauge steel not permitted (titanium straight gauge approved)
- Lacing Restriction – Radial lacing prohibited; use cross or other approved lacing patterns
- Spoke Tensioning – Use calibrated spoke tension meter; mechanical locking nipple or spoke prep recommended
- Tire Compatibility – Designed for 20" BMX tires; verify tire bead diameter matches 406 ETRTO standard
- Tubeless Setup – Requires tubeless-specific tire, rim tape, valve, sealant, and liquid sealer for conversion
- Brake Compatibility – Front or rear rim brake use; not compatible with disc brakes; V-brake compatible as rear only
Important Notes
- Decals included but not pre-installed; follow provided video for proper application
- 2-year limited warranty covers manufacturing defects only; misuse, abuse, improper installation, and vehicular damage excluded
- Warranty valid to original purchaser with proof of purchase
- Maximum 100 PSI tire pressure
- Stickers delivered loose for custom placement
The Fine Print:
Use a calibrated spoke tension meter for all builds. DO NOT build with straight gauge steel spokes. Use only butted or bladed steel spokes. Titanium straight gauge is approved. Radial lacing is not permitted. A mechanical locking nipple or use of spoke prep suggested. Max spoke tension 115KgF. 100 PSI MAX tire pressure.
Warranty:
Onyx BMX rims are designed for BMX racing applications and are backed by a 2 year limited warranty. Warranty covers manufacturing defects only. Damage from misuse, abuse, improper installation, or vehicular damage is not covered by warranty. Warranty term begins on date of purchase by and only to the original purchaser of new Onyx Products (proof of purchase required). For more details, see Limited Warranty .
Tubeless Ready System - Our rims feature a Bead Lock System, needed for the rim to be Tubeless Ready. With the installation of additional items needed you can get the rim ready for tubeless set up, along with the usage of a tubeless specific tire. With a tubeless set up, you can lighten up your wheels, saveing rotational weight, as well as have a sealant inside your tubeless ready tire to help automatically repair small punctures.
Additional items needed to convert to a Tubeless system include Special Valve, Sealant Rim Tape, and Liquid sealer.
V-Braking Compatible - Designed to be used as a rear rim when using a V-brake.
