Wrong wheel size is usually paid for twice—first in production, then in delays, returns, or rework. In B2B projects, fitment risk should be reduced by a repeatable workflow, not by “best guesses”.
Below, a simple fitment workflow is provided for choosing the right wheel size for custom forged wheels—so orders can be approved faster, with fewer disputes.
The B2B Fitment Workflow (Size First, Then Design)
Step 1 — The vehicle must be locked
Before wheel size is discussed, the exact vehicle spec should be fixed.
Must be confirmed (in writing):
- Year / Make / Model / Trim
- Brake package (OEM or big brake kit brand + rotor size)
- Suspension type (stock / coilovers / air)
- Intended use (street, track, off-road, towing)
- Tire plan (OEM size, upsized, or customer’s preferred brand/model)
If any item is unknown, sizing accuracy will be reduced.
Step 2 — The “hard limits” must be defined
Wheel size is not only diameter and width. It is controlled by physical limits.
Hard limits that should be measured or verified:
- Brake clearance (caliper profile + rotor diameter)
- Fender and liner clearance (at full lock and compression)
- Inner clearance (strut, control arm, knuckle)
- Hub bore & center cap space
- Load rating requirement (especially for SUVs, trucks, EVs)
If measurement is not available, an OEM baseline should be used and the risk should be stated clearly.
Step 3 — Diameter should be selected (the brake decision)
In most cases, diameter is chosen to clear brakes first, then to match market demand.
Simple rules used in B2B fitment:
- Bigger brakes → larger diameter will be required.
- Lower-profile tires will be forced by larger diameters, so ride comfort can be reduced.
- EVs and heavy vehicles often need diameter choices that protect load rating and tire availability.
Common B2B practice
- Diameter is selected to meet brake clearance + tire availability + customer style target.
Step 4 — Width should be selected (the tire decision)
Width should be chosen to support the planned tire size and the customer’s performance goal.
What controls width:
- Target tire section width (and recommended rim width range)
- Desired sidewall shape (square vs stretched)
- Traction and handling target
- Fender limit (outer) and suspension limit (inner)
Tip for B2B orders
- Tire model matters. Two “same size” tires from different brands can fit differently.
Step 5 — Offset and backspacing must be engineered (the clearance decision)
Offset (ET) is where most fitment failures happen.
A safe workflow used in production:
- OEM wheel specs are collected (diameter/width/offset).
- Inner and outer movement is calculated versus OEM.
- Brake template and suspension envelope are checked.
- Target poke/flush is confirmed with the buyer.
- A tolerance plan is set (coating thickness, hubcentric ring, spacer policy).
If offset is guessed, rubbing and returns are usually triggered.
A Quick Decision Guide (Used by B2B Buyers)
| Decision | What should be prioritized | What is usually ignored (and causes issues) |
|---|---|---|
| Diameter | Brake clearance + tire availability | Caliper shape and barrel profile |
| Width | Tire spec range + fender limit | Tire brand differences |
| Offset | Inner/outer clearance math | Coating thickness + production tolerances |
| Center bore | Hubcentric fit | Cap clearance and hub protrusion |
| Load rating | Vehicle weight + use case | EV weight and torque |
The Buyer-to-Factory Approval Package (Fitment Proof)
To reduce disputes, the following package should be requested before production:
Requested from buyer:
- Vehicle info + brake/suspension notes
- Target diameter/width and style goal (flush, tucked, aggressive)
- Tire size plan
- Photos: front and rear wheel wells (straight + full lock)
Provided by factory (for approval):
- Final wheel specs (D × W, ET, PCD, CB)
- Brake clearance confirmation (template-based)
- Inner/outer change summary vs OEM
- 2D drawing + 3D rendering (front/rear)
- Notes on spacer/adaptor needs (if any)
Common B2B Mistakes That Should Be Avoided
- Diameter being selected for looks only while brake clearance is not confirmed.
- Width being increased while offset is kept “similar”, causing rubbing inside.
- Front and rear being copied even when staggered fitment is required.
- Fitment being approved from one photo without full-lock and compression checks.
- Invoice/spec mismatch (PCD/CB/ET errors) caused by incomplete order info.
A Simple Order Template (Copy/Paste)
To speed up quoting and reduce mistakes, the following format can be used:
- Vehicle:
- Year/Make/Model/Trim:
- Brake kit (brand + rotor size):
- Suspension:
- Use case:
- PCD:
- Center bore:
- Target specs (front):
- Target specs (rear):
- Tire plan (front/rear):
- Fitment goal (flush/tucked/aggressive):
- Finish:
- Quantity:
- Required certificates/marking:
- Shipping port & deadline:
Closing Note (What Should Be Done Next)
If wheel size is being chosen for a custom forged wheel program, fitment should be confirmed by a documented workflow and then locked by an approval package. Time will be saved, and rework will be reduced.
If your vehicle list and target styles are shared, a fitment-ready size proposal (front/rear) can be prepared for wholesale production.