Three-piece forged wheels (3P)
Our three-piece construction (forged centre, outer barrel and inner barrel) gives you more room for customisation than the other two, and a concave look. The three parts are assembled by hand, for extreme widths, an offset (ET) set to the millimetre and a stepped lip. The three-piece is made on quotation, after a study of the measurements. Monoblock and two-piece are the constructions customers ask for most; the three-piece is kept for projects that need it.
The three-piece construction
The forged centre sits between an outer barrel and an inner barrel, and the three parts are assembled by hand. It is the construction that goes furthest: extreme widths, an offset (ET) set to the millimetre, a stepped lip, technical bolts.
For exceptional projects, when the width or the offset you want cannot be reached with any other construction. It is made on quotation.
These words (concave profile, offset (ET), PCD (bolt pattern), fitment) are explained one by one, without jargon, in the Onyx Academy (page in French), our free course.
On quotation
Write to customer service at contact@onyxforgedwheels.com with your car and the width or offset you are after: the Onyx Forged design office studies the measurements, then sends you a quotation with the price and its payment schedule.
And the other two constructions?
All three constructions start from the same metal and the same process: a block of forged 6061-T6 aluminium, then 5-axis CNC machined, never cast in a mould. What sets them apart is the number of parts in the finished wheel.
Monoblock (one piece)
The whole wheel is cut from a single block of forged 6061-T6 aluminium, then 5-axis CNC machined. No separate barrel, no assembly bolts: the wheel is one piece. Of the three constructions, it weighs least and does the most to reduce unsprung mass. The concave profile is machined straight into the face, from a flat profile to a deep concave.
For drivers who put performance and handling first: less mass at the end of each suspension arm means a wheel that follows the road better and a car that changes direction more readily.
Two-piece
A forged centre is assembled to a barrel made to measure. Width and offset no longer depend on the design of the face: you choose them. The lip can be deep, the bolts remain visible, and two-tone finishes become possible, since the centre and the barrel can be finished differently.
For drivers after exact fitment (the position of the wheel in the arch, to the millimetre) and a visual presence that a monoblock cannot match.
Which one to choose?
Monoblock if lightness and handling come first. Two-piece if exact fitment and a deep lip matter most. Monoblock and two-piece are the constructions customers ask for most; three-piece is kept for projects that need it, when the width or the offset you want cannot be reached any other way, and it is made on quotation. If in doubt, the Onyx Forged design office decides from your car's measurements: write to contact@onyxforgedwheels.com, or see how to customise your wheels.
Manufacturing is bespoke: the dimensions are set for one specific car, and your wheels are delivered in 4 to 8 working weeks, shipping included, from receipt of the deposit set by your quotation, and at the earliest from your approval of the measurements, the colour or the 3D render you asked for, under article 5.1 of the Terms and Conditions: a three-piece project is ordered on quotation. Prices on the website are for a set of four wheels, never for a single wheel. Free delivery to mainland France, the European Union, Switzerland, the United Kingdom, Norway and Iceland, and to the French overseas departments and territories on quotation, which sets the delivery time (Terms and Conditions, article 5.2).
Why forged, not cast
A cast wheel is made by pouring liquid aluminium into a mould. As it cools, the metal leaves tiny pores, invisible to the eye.
A forged wheel never goes through a liquid state: a solid block of aluminium is compressed under a force of several thousand tonnes. Its internal grain lines up. The resulting material has no porosity and behaves differently under impact: where a cast wheel tends to crack all at once, a forged wheel deforms before it breaks.
That is the material that is then 5-axis CNC machined: forged 6061-T6 aluminium, an alloy also used in aircraft construction. The full explanation takes two lessons of the Onyx Academy: cast or forged (page in French) and why a forged wheel almost never breaks (page in French).
Frequently asked questions
What customers ask about the three-piece
Why are there no three-piece wheels in the online catalogue?
Because a three-piece wheel has no standard configuration. Its whole point is to set separately the total width, how that width is split on either side of the centre, and the lip depth. Showing a price per diameter would freeze exactly what the construction exists to leave open. Three-piece projects are therefore made on quotation, after a study of the car's measurements.
What is the practical difference between a two-piece and a three-piece?
The number of barrel parts. A two-piece bolts a one-piece barrel to the centre; a three-piece bolts an outer half-barrel and an inner half-barrel on either side of it. The total width and the position of the centre within that width then become two independent settings, which opens up extreme widths and an offset set to the millimetre without redrawing the face.
Does a three-piece perform better than a monoblock?
No, and it should be said plainly. All three constructions are forged from the same 6061-T6 aluminium. At equal dimensions and design, the three-piece is the heaviest of the three, since it adds two flanges and their bolts. You choose it for a geometry or a look that no other construction reaches, not for better handling.
How long does a three-piece take?
The wheels are delivered in 4 to 8 working weeks (Monday to Friday, excluding French public holidays), shipping included, from receipt of the deposit set by your quotation, and at the earliest from your approval of the measurements, the colour or the 3D render you asked for, under article 5.1 of the Terms and Conditions: a three-piece is ordered on quotation. The study of the measurements, done before the quotation, is not added to this time. The time is suspended while a written request for details needed for manufacture is unanswered (article 3.1 of the Terms and Conditions), while an instalment is overdue (article 4.5), and in the event of force majeure (article 7.2). The delivery time, step by step (page in French).
Are your three-piece wheels designed to JWL/VIA standards?
Yes: they are designed to JWL/VIA standards, which set requirements for resistance to fatigue, impacts and dynamic loads. As parts made one at a time to your specifications, they do not go through an individual approval procedure: we would rather say so before you order.