Nordic Cab Bicyle Trailer Testing
The Nordic Cab bicycle trailer has been tested according to ASTM (American Standard for Testing and Materials) 1975-09, which means this bicyle trailer test was designed in 1975 and was last revised in 2009. This test is the most comprehensive and demanding bicycle trailer test available today. This ASTM standard prescribes a series of tests that range from material strength, to tip tests to collision testing.
Nordic Cab uses the well known Swiss testing firm, SGS, to conduct independent ASTM tests while conducting the same tests at our own factory along with tests for the other Nordic Cab functions such as stroller, jogger and ski pulk.
We publish this detailed description of Nordic Cab testing in order to emphasize the difference between a Nordic Cab and cheaper bike trailers you see in large chain stores. Always check to make sure a bike trailer has been ASTM tested before you even consider towing your children behind your bike!
Drop Impact Test
This test begins by loading the trailer to maximum capacity - in our case with 2 anatomically proportional dolls weighing 25 kg or 55 lbs each for a total of 50 kg or 110 lbs. The dolls are secured with the Nordic Cab 5 point safety harness just as your child would be. The seat back is in the upright position.
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The trailer is lifted to a height of 1.2 meters or 47.2 inches and is allowed to fall directly onto a hard cement surface. It is definitely a simulated "crash" but the Nordic Cab trailer passes the test without any sign of damage. The ASTM standard states that the trailer shall be free from any structural damage and neither the seat, nor frame, shall have shifted from its original position by more than 25 mm.
To know the speed at which the trailer hits the floor we can use the formula.
vf2 = vi2 + 2 * a * d.
Bring back memories form physics class?
In other words - the final speed is equal to the start speed + 2 times acceleration times the distance.
If the trailer is released from a height of 1.2 meters, acceleration will be equal to gravitational pull - that is 9.8 m/s2. The trailer will then have the following speed when it hits the floor:
v2 = 0 + 2 * 9.8m/s2 * 1,2m
v (velocity) = 4.8m/s or 18 km/hr (11mph) |
Remember that the trailer hits the cement floor at this speed and there is a sudden violent stop. With 50 kg in the trailer, this is a significant collision, and the Nordic Cab trailer comes out unscathed. Think of the force on the frame, the seat and the safety harness...
The lesson here is to always use the safety harness as instructed in the user manual. In addition, a proper fitting CPSC approved helmet should be worn by each occupant. When you see the Drop Impact test performed, you understand why it is so important to choose a bicycle trailer that has been ASTM tested. It also makes you understand the importance of Nordic Cab's durable hard plastic base.
Bumpy Road Test
In this test the Nordic Cab trailer is placed on a type of tread-mill or drum, equipped with bumps to simulate riding on a gravel road or forest trail. The test lasts for 10,000 rotations at a speed of 12-13 km/hr or 7-8 mph.
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The speed bumps in this test are 38mm (1.5 in) high and 50mm (2 in) long, with a 45o slant for the wheel to roll over. These are good size bumps which create quite an impact and a significant jossling motion in the cab. The trailer must withstand repeated force as the wheels hit the large bumps at a speed of 12-13 km/hr or 7-8mph. This test lasts several hours.
This test not only subjects the wheels of the bike trailer to a beating, but the entire trailer construction from cab, to frame to axles to bike fork... All parts of the trailer are tested for strength, durability and design - and the Nordic Cab passes with no problems! |
Coupling Security Test
Now comes testing of the bike fork and bike hitch. In this test the motorized cylinder rotates 100,000 times and with each rotation the trailer is pushed and pulled in a jerking motion to test the strength of the coupling.
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This test simulates acceleration and rapid braking with the trailer in tow - and again the Nordic Cab passes with flying colors! |
Tipover Resistance Test
In this test the Nordic Cab is placed on a tip table. Two dolls, each weighing 25 kg or 55lb (the same as for every Nordic Cab test) are fastened into the safety harness just as your child would be. The table is lowered on one side such that the trailer begins to tip with the gravitational force. We continue to tip the table until the wheel on the upper side of the table begins to lift off the surface. We take note of the table angle at this point. In some tests we allow the trailer to roll completely off the table and we measure to make sure no structural damage has been sustained, the safety harnesses are still 100% functional and the dolls, seat and frame have not undergone any significant displacement.
The wheel on the upper side shall not lift off the surface before the angle reaches 30 degrees with 2 dolls in the trailer, or one doll in the middle position. When one doll is placed on the downward side, the angle standard is 25o. Again, the Nordic Cab passes the test!
In the most recent 09 version of the ASTM test the trailer shall not roll off the tip table. Instead the trailer is subjected to an impact by a weight hitting the frame overhead - no damage or measurable movement to the frame construction is allowed. The Nordic Cab passes the test!
In House Nordic Cab Testing
Freeze Testing
All plastic parts of the Nordic Cab are subjected to freezer tests at -20o Celsius or -4o
Farenheit for 48 hours. Thereafter we test for breaking point, flexibility etc. All plastic materials will be affected somewhat by extreme temperatures, but we reject any materials that show a significant change in functionality after freezer tests.
Environmental Testing
We are as concerned as our customers about the environment. Not only is the Nordic Cab, by nature, a product that can replace automobile use and encourage families to be more active outdoors, the Nordic Cab is also designed to last a life time. It converts to a cargo trailer for use after the kids outgrow the seat!
At Nordic Cab we think long term - from choice of materials to the entire manufacturing process. Some bicycle trailers are made with PVC and harmful phthalates which can be harmful to the factory workers who make them and to the environment when the product is discarded. We try our utmost to use materials that are recyclable and non-toxic. We research the newest materials and production methods and spend extra dollars to ensure the Nordic Cab is safe for children and the planet. An example is the Nordic Cab windows - they are 100% PVC free - as is the entire Nordic Cab bicyle trailer.
Extreme Trailering
In addition to all the ASTM tests, we have, of course, used the Nordic Cab ourselves under extreme conditions - as a bike trailer, hike trailer and x-country ski pulk. We bike and ski pulling each other in the trailer (and I can tell you we each weigh a good deal more than 50 kg or 110 lbs:) It's fun and it's a great way to test the strength and construction of our product.
We seek out rough terrain and drive over gnarly curbs. We cut corners, brake fast and weave in and out - just to see the reaction of the trailer. We ski with excess weight and pull the Nordic Cab in deep un-groomed snow. We pull the pulk downhill, brake fast and ski sideways across steep hills. There's not much we haven't tried with the Nordic Cab.
Our goal is for your child to be happy, safe and comfortable while you ride out front with sound peace of mind.
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