The dimensions to understand
Diameter and width
Wheel diameter describes the nominal tire bead-seat diameter, not the overall outer edge. Width describes the distance between the bead seats. The chosen tire must be approved for the wheel width and appropriate for the vehicle.
Offset
Offset is the distance, in millimeters, between the wheel’s mounting surface and its centerline. A more positive offset moves a wheel of the same width further inward. Changing width at the same time changes both inner and outer clearance, so offset cannot be judged alone.
Bolt pattern and center bore
Bolt pattern describes the number of fasteners and the diameter of their pitch circle.s with the hub. Confirm hub dimensions and the correct fastener type, seat, length and thread engagement; a matching bolt count is not sufficient.
Clearance is a separate check
A wheel with the correct diameter and bolt pattern can still contact a brake caliper. Check the barrel and spoke clearance against a verified brake template, especially with upgraded brakes. Check inner suspension clearance, outer fender clearance and tire clearance through steering and suspension travel.
Lowering, alignment changes, spacers and tire profile can alter clearance. Do not rely on a photograph or another car’s setup as proof of fitment. Final evaluation belongs with a qualified installer.
Load capacity and vehicle systems
Confirm an appropriate wheel load rating for the specific vehicle and use. Tire load and speed ratings, rolling diameter, TPMS compatibility and any staggered setup also need review. All-wheel-drive systems may have specific tire-circumference requirements.
Prepare your fitment brief
Vehicle: year, make, model, trim and market.
Changes: brakes, suspension, ride height, bodywork and spacers.
Current setup: wheel dimensions, offset, tire sizes and known clearance issues.
New direction: use case, desired appearance, material and preferred size, if known.
If a measurement is unknown, mark it as unknown. Guessing an offset or bolt pattern is less useful than requesting a proper review.
Choose the material next
Explore custom forged aluminum wheels or forged magnesium wheels, then request a quote with your vehicle details.
PCD and bolt pattern
PCD (pitch circle diameter) is written as stud count by circle diameter, e.g. 5x112 or 5x120. It must match the hub exactly; "wobble bolts" are not a substitute for correct drilling on a custom wheel.
Offset and backspacing
Offset (ET) is the distance in millimetres from the wheel centerline to the hub mounting face. Higher positive offset pulls the wheel inward; lower offset pushes it out. Changing width and offset together decides whether the tire clears the strut and the fender. A few millimetres matter.
Center bore and hub-centric fit
A hub-centric wheel is machined to the hub diameter so the hub, not the bolts, centers the wheel. On a fully custom wheel the center bore can be machined to your vehicle, avoiding centering rings.
Seat type and hardware
Lug seats are conical (60°), ball/radius or flat. Mixing seat types is a common cause of loosening. Specify your bolt or nut thread and seat, and torque to the vehicle manufacturer's value.
Load rating
Each wheel's rated load must exceed the heaviest axle load divided by two, with a margin. Heavy EVs and SUVs need particular attention; the load requirement is part of every VEXORA specification.
Brake clearance
Large calipers need clearance to the spoke back and barrel. Use the brake manufacturer's template or measure caliper face and radial clearance.
For different front and rear sizes, see staggered forged wheels fitment. For capacity, see forged wheel load rating.
Fitment FAQ
Can a custom forged wheel fix fitment a stock wheel cannot?
Often, yes, because offset, width and spoke profile are drawn for your car. VEXORA does not keep a stock catalog or ready-to-ship inventory. Every wheel is engineered and forged to your vehicle, dimensions and finish.
Do I need exact numbers to start?
No. Share what you know and it is confirmed before production.
Ready? Send your brief for forged aluminum or forged magnesium wheels.
Related: Forged wheel brake clearance for big brake kits — how BBK caliper envelopes change custom forged inner profiles.
Check numbers before ordering: use the wheel offset calculator, learn how to measure wheel offset, and compare offset vs backspacing.
Special cases: single-nut hubs in center lock wheels; bolt seat, bore and 4MATIC notes in Mercedes monoblock wheels.
Diameter is part of the brief - read 18 inch vs 20 inch forged wheels.