Exhaust System Resonator Specification Example for Off-Road Bikes: Sealed Unit
Exhaust System Resonator Specification Example for Off-Road Bikes: Sealed Unit
This is a worked specification for exhaust system resonator in a sealed unit programme. It is the document we would send a buyer who asks what exactly they are getting: the material, the dimensions that are actually controlled, the finish, and the checks that happen before anything is packed.
The sealed unit version exists because the duty cycle on off-road bikes is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually a fitment that looked right on paper and failed on the bench.

Example specification
| Item | Exhaust System Resonator |
|---|---|
| Application | Off-Road Bikes |
| Version | Sealed Unit |
| Base material | PU Leather |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | zinc plated |
| MOQ | 1,000 pieces per specification |
| Sampling | 14 working days, 3 days per revision |
| Compliance | ISO/TS 16949 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — PU Leather, in this example.
- List the dimensions that are actually controlled and the tolerance on each.
- Name the finish and what it has to survive.
- State the inspection level and who pays when a lot fails.

Processes involved
- heat treatment
- rubber vulcanisation
- electroplating
- precision stamping
- surface grinding
- die casting
Where this example applies
Programmes that run sealed unit most often specify this build for off-road bikes. Related applications include three-wheelers, dealership service, city buses, assembly programmes, workshop replacements.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 4.0 sampling on the finished lot.
- Finish inspection under agreed lighting.
- Carton drop test on the first lot of a new packing specification.
Questions buyers ask
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the ISO/TS 16949-compliant build instead of a fresh interpretation.
How is packing specified?
Individual packing, inner box quantity and carton marking are confirmed at quotation stage so the cartons arrive ready for your warehouse.
What happens if a lot fails inspection?
The lot is re-inspected against the golden sample, and replacement pieces ship on the next available booking at our cost.
Can you match an existing sample?
Send a sample and we will reverse-engineer the specification, then produce a counter sample for approval before any bulk starts.
Ask for the current catalogue and the specification sheet for this line.



