E-Bike Manufacturing, Quality Control & In-Process Inspections

By The Pro QC Quality Assurance Team A bicycle is made up of several components – a frame, wheels, handlebar, saddle, pedals, a gear mechanism, brake system, and other various accessories. The number of components that need to be put together to form a final product that is safe for use, as well as the fact that many of these components come from different, specialized manufacturers, means that constant quality inspections are required throughout the final assembly process. So how is a bicycle assembled and what are the main components of in-process quality control inspections and the usual defects?

How is a bicycle assembled?

Manufacturing electric bicycles (e-bikes) and bicycles is roughly an eight-step process:

1. Raw materials arrive
2. Metal is cut into rods to prepare the frame
3. The various parts are temporarily assembled before being welded to the main frame
4. The frames are hung on a rotating belt, and primer is sprayed
5. The frames are then sprayed with paint, and exposed to heat so the paint can dry
6. Brand labels and stickers are placed onto the relevant parts of the bicycle
7. All the components are assembled – frames, lights, cables, handlebars, chain, bicycle tires, the saddle, and for e-bikes, the battery is labeled and installed
8. Bicycles are packed and prepared for shipping

This highly simplified process is undercut by the need for assembly inspections. Each production step requires an in-process inspection to ensure the manufacturing process is correct and that it enables all the parts to integrate effectively.

What is an In-Process Inspection?

Also referred to as an ‘IPI’, in-process inspections are conducted by a quality inspection engineer who is fully knowledgeable about the bicycle parts industry. The inspector will walk through the process, inspecting every component from the incoming raw materials until the packaging of the final product. The end-goal is to ensure that the product is compliant with all regulations. Through the step-by-step process, any anomaly or defect can be identified from the source and corrected quickly. If there are any major or critical problems, the customer can also be notified much faster. In-process inspections also serve to update the customer at all points – whether the factory continues to follow the original specifications for the e-bike or bicycle, and whether the production process remains on schedule.

What does In-Process Inspection verify?

At Pro QC we conduct third-party inspections, and our engineers will inspect each step of the manufacturing process, controlling quality at each production step through the assembly process. The main touch points during the in-process inspection of e-bikes include:

• Components/features according to the Bill of Materials and client specifications
• Accessories check: user manual, battery notice, information card, CE declaration of conformity, keys, front basket, luggage bag, light set
• Design & Labels check: stickers according to the client’s specifications – attached to the frame, bicycle trims, etc.; EPAC label, labels on battery and charger, warning information, compatibility label battery, charger label, motor label (specifically for e-bikes)
• Visual check: workmanship check, overall product check: frame, saddle, chain, cover chain, tires, wiring and connectors, battery, charger, etc.
• Function check; Riding tests (finished product): ensures the e-bike can be ridden properly (straight line and turns), all assistance modes and display should have proper functions, motor assistance/brakes/transmission working properly, no unusual sounds or functions, tires inflated and mounted properly on rims, spokes installed properly in the rims
• Packaging (finished product): carton label should mark the brand, model number, part number, barcode, frame number; properly protected bicycle and lights in the box, the battery must be installed with the system switched off

Mechanical and Electrical safety components for the e-bikes are also inspected thoroughly to ensure all compliance standards are met. During production, the focal point is the bicycle frame – whether, for an e-bike or a regular bicycle, this is the most important component of the entire process. The frame inspections call for further quality control of bicycle inspections – throughout this, the engineers verify that the QA/QC methods of the manufacturer are sufficient to maintain the quality of the final product. At the final assembly point, the third-party inspector will visually check the assembled product, and conduct performance tests, as well as function tests and rides to ensure that the e-bike or bicycle works as designed.

What are some common defects identified during e-bike in-process inspections?

Before beginning in-process inspections it is important to check the quality of incoming materials. Some manufacturers believe they have a good relationship and skip this step. No matter how good the relationship is, the raw materials must still always be checked. It is also important to keep in mind that the sampling rate should not be set too low or there is a greater chance of the defects below not being picked up during the in-process inspection. Minor defects can also include minor visual or technical quality issues which are easy and cost-effective to fix – including small scratches or other defects on the paintwork or component, poor brake or gear adjustment. Major defects are slightly harder to tackle, but not impossible. These include clear issues on visual or technical quality, which are harder to repair or require more expensive service or replacement parts. Defects of this nature include highly visual scratches or other defects on paintwork or component, dents in any component, large technical issues on brakes or chain, missing parts, off-center frame, loose tire spokes, parts outside the specification, a wrong label that needs to be changed, noisy e-bike motor, etc. Critical defects require urgent action – these include the product being out of compliance with international regulations and potentially presenting a danger to users, usually through serious issues with electrical and mechanical safety. As we mentioned in our article on Inspection Sampling, Pro QC has been conducting in-process inspections for almost four decades. We look forward to discussing your quality challenges and developing a customized inspection plan.