By Matthew Milasius
In 2016, a British bike enthusiast died after the front wheel detached on his bike. The victim was traveling at speeds of only 20mph and likely applied the front brakes suddenly to swerve away from a hazard in the road. But the bonding between the bike’s carbon-fiber blades and aluminum fork crown failed, causing the wheel to detach.
The bike fork manufacturer, Upgrade Bikes, had actually already issued a recall for the component, which they imported from abroad, the previous year. But consumers had only returned 246 out of about 2,000 bikes before the fatal crash.
Safety is a major concern for bicycle importers, even long after their products hit the market. But importers can almost always prevent and identify bike safety issues by conducting some simple bike tests during a pre-shipment bike inspection.
With a thorough bicycle inspection checklist, you can discover any faulty components before they jeopardize your business or put your customers in danger (related: 5 Essentials of a Quality Control Checklist [eBook]).
Here are 13 on-site bike tests for your bicycle inspection checklist that will help keep your product safety and quality in check.
9 general on-site bike tests for your bicycle inspection checklist
A common product in many homes, bicycles are internationally governed by regulations and bike testing standards. Common international standards for bike safety and function include:
- The U.S. Code of Federal Regulations (CFR) Title 16, Part 1512 and
- ISO 4210, which replaced EN 14764 in 2015
Be sure to include testing procedures and your quality tolerances with each test checkpoint when creating your bicycle inspection checklist. This information will help you maintain consistent standards and clarify expectations for your inspection team (related: How Product Inspectors Use Quality Control Checklists).
Formatting your requirements into an itemized chart like the one below will help keep information organized for both your supplier and QC team.
You’ll notice the use of special inspection levels from the ANSI ASQ Z1.4 AQL table in this bicycle inspection checklist.
AQL special inspection levels are divided in four: “S-1”, “S-2”, “S-3” and “S-4”. Professional inspectors typically use these levels for on-site tests that:
- Are destructive to the product
- Are expensive or tedious to perform, or
- Tend to yield similar results across all units in the order
As you’ll see for the bike tests below, AQL special inspection levels are commonly used for bike testing. Using these special inspection levels helps you test a smaller sample size, while still using a statistically-valid acceptance sampling method (related: The Importer’s Guide to Managing Product Quality with AQL [eBook]).
1. Torque checks on nuts and bolts
Torque checks on nuts and bolts help ensure all bike parts are properly secured.
Bolts installed with the wrong tightness can cause several problems for cyclists. An excessively tight bolt can limit movement. But a loose bolt can also turn a safe descent down a hill into a traumatic accident.
Bike testing standards from the United States Consumer Product Safety Commission (CPSC) explicitly require importers to verify fasteners: “Screws, bolts, and nuts used to fasten parts may not loosen, break, or fail during testing.”
You don’t need to perform a torque check on every single nut and bolt on all the bikes you manufacture. Since a torque test would be rather time-consuming to perform on hundreds of bolts, you might consider conducting the torque test on an S-1 sample size instead.
Some of the more important bolts and nuts to check include:
- Crank bolts securing the crank to the axel of the bottom bracket
- Disc caliper bolts attaching the caliper to the frame or fork
- Rear derailleur bolts securing a mechanical type derailleur to the bike wheel
- Kickstand bolts attaching the kickstand to the bike
- Rear wheel nuts holding the rear wheel onto the bike
A torque wrench is a standard piece of equipment for bike manufacturers. But confirm with your supplier ahead of inspection anyway to be sure staff at the or inspection site will have a torque wrench available for this test.
2. Tire pressure check
Tire pressure has a major impact on the rider’s experience. An overinflated tire transmits impact to the rider, sacrificing speed and riding comfort. And an underinflated tire can make it much harder for the rider to pedal.
CPSC tire pressure guidelines require you to ensure the tire stays on the rim when inflated to 110 percent of the recommended pressure.
All you need for this check is:
- A tire pressure gauge (which your factory should be able to provide)
- Product specifications for optimal pressure level
Using the tire pressure gauge, check the tire pressurebefore and after riding the bicycle. You or your inspector should record the pressure on your bicycle testing checklist, so you can clearly see whether there is a significant drop in pressure after riding. Perform this check on an AQL S-1 sample size or larger.
3. Assembly and full function checks
Assembly and full function checks help you verify whether the bike functions properly and as outlined in the user manual.
After assembling an S-1 sample size or larger, the inspector should adjust a few parts on the bikes to determine stability and functionality, including:
- Chain adjustment
- Saddle adjustment
- Handlebar height adjustment
You’ll know there’s a problem with the bike’s assembly if any of the parts start to malfunction during the adjustments. Common issues might include a wobbly seat, loose chains or misaligned handlebars.
The last thing you want is for your customers or end users to experience these problems when assembling or adjusting their bike.
Be sure to provide your instruction manual to your QC team along with your bicycle inspection checklist. This will help the inspector simulate the user experience of assembling and adjusting the bike based on those instructions.
4. Riding test
No effective product inspection is complete without some kind of “real-world” testing to simulate product function. And quality control for bicycles similarly requires a ride test. Even if you check all the individual components of a bike, you still need to ensure they function properly together.
Bicycle importers can take a few different approaches to riding tests.
You might ask your inspector to ride the bike continuously for 30 minutes to simulate long-distance riding. But in this case, you may have to test a smaller sample size to allow enough time during inspection.
Or you might have the inspector ride a shorter distance of 200 meters on a larger S-4 sample size.
Either way, the riding test should include:
- Pedaling intensely and accelerating swiftly
- Pedaling gently and accelerating softly
- Making hard and soft turns (both left and right)
- Braking hard and soft
- Riding over at least three bumps
The inspector should verify the bike is in the same condition before and after completing the riding test.
You might want to notify your supplier in advance if you’ll be inspecting the bike at their factory so they can ensure there is adequate riding space available.
5. Noise and abnormal sound check
While it’s important to ride the bike and understand its “feel”, the inspector should also use the ride test to listen for any abnormal sounds. Strange noises are often a sign of problems.
No equipment is required for this—the inspector need only listen for problems. They can perform this check during and immediately following the riding test on the same sample size.
When checking for abnormal sounds, the inspector should:
- Use an S-1 sample size or larger
- Stand one meter away from the bike
- Rotate the wheels of the bike
- Test in a quiet environment
The quieter the environment, the better. But aim for a testing environment with background noise lower than 60 decibels (dB).
6. Fatigue test
A fatigue test checks for any problems that may arise when the bike is subjected to the normal stress of regular use.
Imagine a typical commuter who rides their bike to work every day. Within the first six months of owning that bike, they’ll have lowered and raised the kickstand 100-200 times. And that’s just from riding to and from work.
Imagine their disappointment if the kickstand breaks just two months into their new purchase.
The most important parts to test are the most frequent consumer touchpoints of the bike, including:
- Hand brakes – Squeeze the handlebars 50 times with a force of 445 newtons
- Pedals – Spin each pedal in one full rotation 50 times
- Kickstand – Raise and lower the kickstand 50 times
Skipping this test can be tempting because testing fatigue with 50 repetitions on each part is rather tedious. But be sure to test the parts on at least 1 sample per stock keeping unit (SKU).
The parts shouldn’t break, fail or fall out of alignment during the test. Keep an especially close eye on the brakes to look for any moving clamps or parts.
7. Rub test on labels
This test helps you ensure your bike rating labels won’t peel off or become unreadable during the life of the product. Bike labels are a mandatory legal requirement for most Western markets. And retailers may refuse to stock your products if your labeling is compromised.
According to CPSC bike testing requirements:
Every bicycle must have a permanent marking or label that shows the name of the manufacturer or private labeler and that the manufacturer or private labeler can use to identify the month and year the bicycle was manufactured.
Electric bikes must also have an energy rating label to help consumers assess energy efficiency.
Perform this test on an S-1 sample size or larger. You’ll need two cloths, one soaked in water and the other in alcohol. Rub the logos with each cloth for 15 seconds.
Make sure the logos and markings are still intact and don’t peel off during or after the test.
8. Adhesive test on printing and logos
In addition to safety and legal labels, bicycle manufacturers often also print logos and other information directly onto their products. And customers’ inability to recognize your logo or read the information printed on your bike can damage your brand.
While the rub test focuses on the manufacturer label, the adhesive test ensures any other text and logos won’t peel off under normal conditions.
Choose an S-1 sample size and use 3M tape (an industrial adhesive tape) for this test.
Apply the 3M tape at a 45-degree angle to the printing or logo’s surface. Firmly press down and then quickly remove the tape. The printing or logo should not peel off after the test.
9. Coating cross-hatch test according to ASTM D3359
Bikes often come in multiple colors, styles and designs. Especially for children, there’s something exciting about receiving a shiny, new bike in your favorite color. So you might have difficulty selling your bikes to customers if the paint easily peels or scratches off during shipping and handling.
The cross-hatch test helps determine whether paints and coatings can resist wear. Perform this check on a sample of at least one unit per SKU. Because this test typically renders the product unsellable, you’ll probably want to limit the sample size.
You or your inspector will need adhesive tape and a sharp blade, like a razor blade or knife, to perform the cross-hatch test.
Following the ASTM D3359 standard, choose a blemish-free area on the bike and use the blade to make 11 horizontal and 11 vertical cuts in a lattice pattern. Each line should be 20 millimeters long and the cuts should penetrate the coating.
Next, gently wipe or brush the area free of any particles or flakes. Then firmly place the tape over the area and remove it. The product passes the test if no more than five percent (five squares in the grid) of the coating peels off.
On-site bike tests for braking systems
Your bicycle inspection checklist is incomplete without clear brake testing requirements.
Brakes are a vital part of a bicycle, both in terms of function and safety. And unlike the seat or frame, it’s hard to gauge how well the brakes will work from a visual inspection alone.
10. Braking system assembly check
The first step in the braking system assembly check is to verify that the bike has two independent brake systems: one for the front and one for the back.
Check the brake construction and assembly to ensure all brake parts are properly assembled—typically on an S-1 sample size.
Pay special attention to the cable pinch bolts that secure the brake cable to the lever arm. The cable pinch bolts shouldn’t sever any of the cable strands when assembled according to your user manual’s instructions. Cable strands already severed during inspection are typically a sign of incorrect assembly.
Verify that the ends of the cables are protected with a cap that can withstand force up to 20 newtons to prevent unraveling.
11. Brake block and brake pad assembly security test
Brake pads, or brake blocks, are steel backing plates with a friction material bound to the surface facing the wheel. When the rider presses the brake, the caliper squeezes the two pads together onto the spinning rotor to stop the bike.
To perform this bike test:
- Use an S-1 sample size or larger. Perform the test on a fully assembled bike with a rider or rider-equivalent mass. The combined mass of the bicycle and rider should weigh at least 100 kilograms.
- Operate each brake lever with either a force of 180 newtons or enough force to bring the brake-lever into contact with the handlebar grip, whichever is less. The test force must be applied at a distance of “b” in the diagram below, which must be a distance of at least 25mm from the free end of the brake lever. Maintain the force on the brake-lever.
- Subject the bike to five forward and five backward movements.
- Move at least 75mm in distance for each movement.
The brake block or pad’s friction material must remain securely attached to the holder, backing-plate or shoe and should not fail after testing.
12. Hand-operated braking system strength test
The hand-operated braking system strength test will help ensure consumers can use the brakes with a reasonable force.
Confirm the braking system on a fully-assembled bike is adjusted according to your recommended settings before performing this test.
Prepare an S-1 sample size and apply force to the brake lever of each unit. Point “F” in the above reference diagram shows where to apply force.
Apply 450 newtons or less of force and verify:
- The brake lever comes in contact with the handlebar and/or handlebar grip, and
- The brake extension lever maintains its level with the surface of the handlebar
Perform this test 10 times on each hand brake or extension lever. This helps ensure the brakes will hold up under repeated use.
13. Braking distance test
Cyclists often need to stop quickly and abruptly, especially when riding on crowded city streets and sidewalks. The braking distance test verifies how long it takes the bike to come to a complete halt when traveling a certain speed. A bike that can’t stop quickly may have unreliable brakes.
CPSC bike testing standards require that bikes with both handbrakes and footbrakes stop within 15ft (4.57m) when tested by a rider weighing at least 150lb (68.1kg).
Perform the braking distance test on an S-1 sample size at different speeds. You’ll want to test braking using both front and rear brakes together, as well as just the rear brakes separately. And you might want to test the braking distance in both wet and dry conditions to ensure the brakes can withstand environmental changes.
You can include a chart in your bicycle inspection checklist like the one below to set acceptable braking distance standards at specific speeds:
Conducting bike testing isn’t as straightforward as just telling someone to “do QC on a bike”. But having a clear bicycle inspection checklist can help remove ambiguity from the bike inspection process.
A thorough bicycle inspection checklist should always outline bike testing procedures, sample sizes, necessary equipment and who should provide that equipment. Forgetting just one of these factors in your checklist can hinder inspection and result in shipping substandard or even dangerous bikes.
It’s easy to become overwhelmed by all the tests and requirements in a bicycle inspection checklist. But third-party QC firms can help prepare a QC checklist for you if you don’t have the expertise to compile one yourself.
By helping you to identify bike quality issues, a professional QC partner can help you focus more on selling bikes and less on the repercussions of injured riders.
Matthew Milasius is a Client Manager at InTouch Manufacturing Services, a QC firm that performs product inspections and factory audits in Asia for clients in the US, EU and Australia.