Inner Tube for QJMotor SRK 400: Waterproof Version
This inner tube is built for the QJMotor SRK 400 and supplied to a written specification, so the part that comes off the line in the next order matches the one you approved. Fitment, base material and finish are fixed before sampling starts — that is what keeps the waterproof version programme stable once it moves from first order to repeat order.
Most buyers come to us after something went wrong: warranty claims traced back to a single lot, or inconsistent hardness between lots. Both are avoidable when the specification is written down before bulk and the approved sample is kept as the reference.
Specification
| Part | Inner Tube |
|---|---|
| Fitment | QJMotor SRK 400 |
| Version | Waterproof Version |
| Base material | Sintered Metal |
| Typical use | Urban Courier Work |
| MOQ | 500 pieces per specification |
| Sampling | 10 working days, 3 days per revision |
| Bulk lead time | 20-35 days after approval |
| Compliance | REACH |
What decides whether it lasts
- Material — Sintered Metal is the base; treat any substitution as a new approval.
- Hardness and heat treatment — recorded per lot, not per batch of paperwork.
- Fitment tolerance — checked on the actual QJMotor SRK 400 mounting, not on a catalogue drawing.
- Finish — anodising holds up where the machine sees salt, mud and daily washing.
- Packing — individual packing plus inner cartons sized for the workshop bench.
Processes used on this line
- laser cutting
- ultrasonic cleaning
- shot blasting
- rubber vulcanisation
- injection moulding
- cold forging
Fitment notes
Check whether the mounting points on your market version match the catalogue drawing — regional variants are the usual cause of a wrong first order.
Where it is used
The waterproof version build is the one most often ordered for urban courier work. Riders also fit it for roadside assistance, airport ground fleets, mountain roads, wet weather riding.
Ordering
- Confirm the model year and frame number before ordering.
- Approve a sample made from the actual bulk material.
- Fix the packing and marking at quotation stage.
- Book inspection before the balance payment, not after it.
Questions buyers ask
How long does sampling take?
Samples leave the factory in 10 working days, and each revision round adds about 3 days once you have seen the first piece.
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.
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.
What is the minimum order quantity?
The standard MOQ is 500 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
Send the specification you are working to and we will confirm what we can match, what we would change and why.
