ENGINEERING
THE SCIENCE OF OFFSET
Understanding scrub radius, clearance, and how offset affects handling characteristics.
NEW RELEASE
RRT-ULTRA
$1,080.00
RRT-Ultra Custom Forged Car Wheels in Singapore
The RRT-Ultra is one of the most highly optimized forged car wheels available today. It is engineered beyond what most manufacturers are willing to pursue, due to its ultra-deep side cuts, thin-wall sections, and complex geometry that significantly increase manufacturing time and cost. Each wheel requires many hours on a 5-axis CNC machine, making it a true engineering-first product rather than a commercially driven one.
The RRT-Ultra was never designed around mass production or margins. It is an exploration of how far a car wheel can be optimized when performance is the only priority. Every feature follows a strict form-follows-function philosophy. Every corner, profile, and cross-section exists to refine load paths, reduce unnecessary material, and improve structural efficiency.
This approach results in an extreme strength-to-weight ratio that places the Ultra ahead of competing forged wheels. To our knowledge, there is no other forged 6061-T6 aluminum car rim that is lighter while maintaining comparable load-holding capability. These are car rims built for drivers who understand that real performance is measured in data, not appearance.
If you demand the highest level of performance from your car wheels, the RRT-Ultra delivers reduced unsprung mass with exceptional lateral, vertical, and torque load capacity. Lower rotational inertia translates directly into sharper steering response, improved braking feel, and more efficient acceleration.
For those who demand nothing less than the best for their car, the RRT-Ultra represents engineering without compromise.
Thin Wall Technology with Ultra-Deep CNC Cuts
After extensive large-scale testing and development, the RRT-Ultra emerged as a benchmark in advanced forged wheel design. Extensive 5-axis CNC machining allows precise thin-wall sections and ultra-deep spoke cuts that maximize weight reduction while preserving structural integrity.
Many lightweight car wheels on the market focus only on reducing mass, often at the expense of stress management and long-term durability. At RRT, we take a different approach. Every RRT-Ultra wheel is developed using calculations, stress analysis, and real-world data to ensure that reduced weight does not compromise strength or safety.
If you are searching for car rims that are genuinely lightweight yet structurally sound, the RRT-Ultra stands apart.
5-Axis CNC Deep Spoke Cuts to the Barrel Brink
The RRT-Ultra features detailed 5-axis CNC machining that extends deep into the spoke structure and toward the barrel. This process removes excess material from low-stress areas, reducing rotational mass and wheel inertia.
The result is noticeable improvement in braking response, acceleration, and overall vehicle feedback. Due to the time-intensive machining process and high production cost, this level of detail is rarely applied in modern car wheel manufacturing.
RRT chooses to apply it anyway.
Our forged car wheels are built without shortcuts. Every machining hour serves a purpose, and every design decision is made to extract maximum performance from the material. This philosophy is what defines the RRT-Ultra and separates it from conventional aftermarket wheels.
Available Colors
*Actual colors may vary due to current lightings.*
Weight Description of RRT- ULTRA
| kg | kg | kg | kg | kg | |||||||||
| 17x7 | 5.8 | 18x8 | 6.6 | 19x8 | 7 | 20x9 | 7.5 | 21x10 | 9.35 | ||||
| 17x8 | 6 | 18x8.5 | 6.75 | 19x8.5 | 7.2 | 20x9.5 | 7.8 | 21x10.5 | 9.55 | ||||
| 17x9 | 6.2 | 18x9 | 6.95 | 19x9 | 7.35 | 20x10 | 8.1 | 21x11 | 9.8 | ||||
| 18x9.5 | 7.05 | 19x9.5 | 7.5 | 20x10.5 | 8.35 | 21x11.5 | 10 | ||||||
| 18x10 | 7.25 | 19x10 | 7.7 | 20x11 | 8.55 | ||||||||
| 18x10.5 | 7.4 | 19x10.5 | 7.85 | 20x11.5 | 8.75 | ||||||||
| 18x11 | 7.6 | 19x11 | 8.1 | 20x12 | 9.15 | ||||||||
| 18x11.5 | 7.8 | 19x11.5 | 8.4 | ||||||||||
| 19x12 | 8.7 |
** weight specs may verify due to different requirements such as brake clearances and load requirements **
Performance and Practical Benefits of RRT-Ultra
Base Material & Mechanical Properties
| Aspect | RRT-Ultra Forged Wheels | Cast / Flow Formed Wheels |
|---|---|---|
| Material | 6061-T6 wrought (forged) aluminum | A356 cast aluminum alloy |
| Manufacturing process | Forging from solid billet | Casting / flow forming |
| Yield strength | ~280 MPa | ~190 MPa |
| Elongation before failure | ~15% | ~3–5% |
| Deformation tolerance | Very high | Limited |
| Failure behavior | Deforms progressively | Fractures more easily |
| Weight vs strength | Lighter for the same strength | Heavier to reach similar strength |
What this means in real terms:
For an equivalent design, a forged wheel can withstand roughly 30% more force before deformation and up to 3× more deformation before material failure. This is why forged wheels can be both lighter and significantly tougher.
Why 6061-T6 Is Forged, Not Cast
| Topic | Explanation |
|---|---|
| Why 6061 can’t be cast | 6061 is a wrought alloy. When cast, contraction during cooling causes internal tearing |
| Casting speed vs forging | Casting: ~3 minutes per wheelForging (RRT Extreme): up to ~1800 minutes |
| Why casting is cheaper | Faster cycle time and simpler tooling |
| Why strength is higher in forging | Grain structure is aligned and compacted during forging |
| Why A356 is used for casting | High silicon content improves flow and prevents hot tearing |
| Trade-off of A356 | Easier to cast, but sacrifices strength and durability |
Load Path Engineering & Structural Strength
| Engineering Focus | RRT-Ultra Approach |
|---|---|
| Load path design | Smooth, uninterrupted load transfer from barrel to bolt seat |
| Stress concentration | Minimized to the practical limit |
| Spoke-to-barrel interface | Optimized geometry; webbed structures in advanced series |
| Lateral load resistance | Designed for extreme lateral impacts and racing scenarios |
| Real-world abuse tolerance | Proven in wheel-to-wheel contact and off-track excursions |
| Industry comparison | Engineered beyond minimum regulatory strength requirements |
Polar Moment of Inertia & Profile Optimization
| Design Principle | RRT-Ultra Execution |
|---|---|
| Polar moment of inertia | Maximized through large, hollow, thin-wall profiles |
| Visual appearance | Chunkier spokes, but lighter and stronger |
| Structural technique | Aggressive side cuts, hollow box sections, webbing |
| Result | Higher stiffness at lower mass |
| Engineering analogy | Large hollow tube is stiffer and lighter than a small solid one |
| Outcome | Light does not equal weak when geometry is optimized |
Custom Fitment & Performance Advantage
| Fitment Aspect | RRT-Ultra Advantage |
|---|---|
| Production method | Custom built per vehicle |
| Use of adapters | No center rings, wobble bolts, or spacers |
| Brake clearance | Supports large brake systems (e.g. 390mm setups) |
| Stagger options | Reverse stagger, non-standard widths, offsets |
| Performance impact | Improved handling, reduced unsprung mass |
| Competitive edge | Fitment optimized for camber, wide fenders, and track use |
Bottom line:
Why invest in a lightweight wheel only to compromise it with heavy spacers? Proper fitment is a performance multiplier, not a cosmetic detail.
ENGINEERING PROTOCOL
BUILT BEYOND SPEC
Every wheel in this series is forged and machined to tolerances that exceed conventional standards.
engineering
FORGED 6061-T6
Aerospace-grade billet aluminum, heat-treated to T6 specification.
precision_manufacturing
CNC MACHINED
Five-axis CNC machining ensures micron-level precision on every surface.
verified
CERTIFIED
Exceeds JWL, VIA, and TUV standards for road-legal performance.
local_fire_department
HEAT TREATED
T6 heat treat process maximizes strength-to-weight ratio.
VELOCITY & RIGIDITY
FORGED VS. CAST
Our forging process aligns grain structure for superior strength at a lower weight.
speed
LIGHTWEIGHT
Up to 30% lighter than cast equivalents, reducing rotational mass.
bolt
STRENGTH
Forged grain structure yields higher tensile and fatigue strength.
balance
BALANCE
Dynamic balancing to within 5 grams for smooth high-speed rotation.
| Specification | RRT Forged | OEM Cast |
|---|---|---|
| Weight (19x8.5) | 8.9 kg | 12.4 kg |
| Tensile Strength | ≥310 MPa | ≤220 MPa |
| Fatigue Life | 1,000,000+ cycles | ~500,000 cycles |
| Porosity | None | Visible micro-voids |
PRECISION FITMENT
DESIGNED FOR YOUR CHASSIS
Each fitment is engineered to clear big brake kits and maintain optimal suspension geometry.
check_circle
HUB CENTRIC
Precision-bored center bore matches your vehicle hub for vibration-free fitment.
build_circle
BIG BRAKE CLEARANCE
Designed to clear multi-piston calipers without spacers.
straighten
OPTIMAL OFFSET
Custom offset engineering for perfect flush fitment with the fender.
weight
LOAD RATED
Each fitment is load-rated to exceed vehicle manufacturer specifications.
FIELD DEPLOYMENT REGISTRY
ON THE ROAD
Real-world deployments of this wheel on notable builds.
NISSAN GT-R R35
AF-M1 Monoblock in Brushed Clear — 20x10.5 square setup.
BMW M4 G82
AF-M1 Monoblock in Satin Titanium — 19x9.5 / 19x11 staggered.
PORSCHE 992 GT3
AF-M1 Monoblock in Gloss Black — 20x9.5 / 21x12.
TECHNICAL INSIGHTS
FROM THE LAB
Deep-dive articles on the engineering behind the AF-M1 platform.
MATERIALS
6061-T6 VS. 7075-T6
Why we choose 6061-T6 aluminum for monoblock construction and where 7075-T6 excels.
DESIGN
I-BEAM SPOKE TECH
Finite element analysis behind our signature I-beam spoke reinforcement design.