Roof Cargo Box Safety

 

A leading European safety organistion ran a comprehensive safety test of a selecetion of roof cargo boxes. The results were very interesting and the videos highlight the importance of roof box safety.

 

What was tested?

Layout

The design of the roof boxes was examined and evaluated with regard to sharp edges and possible risks of injury. Furthermore, the tightness of the roof boxes was tested. For this purpose, the unloaded roof box was mounted on the base of the car and laid out on the inside to the sealing edge with blotting paper. At the height of the roof box, a blower was placed at a distance of 3 meters in front of the box and the test rig was sprinkled with about 180 liters of water for 15 minutes.

The cold test was carried out in accordance with DIN 75302 (roof rack for passenger cars - Safety requirements and testing, draft 2006). Here, in the ADAC cold chamber at -20 ° C, a 2.5 kg test specimen was dropped on each roof box at several defined points. Prior to this test, all roof boxes were conditioned at -20 ° C for at least 6 hours.

The verification of the stated volume was carried out by means of reporting. Here, the upper and the lower part of the roof box was filled with bulk material (packaging flakes) and then measured its volume. This method achieves an accuracy of about +/- 10 liters.

Handling

In the test category handling, the instructions for use with regard to the required information according to DIN 75302, their readability and their comprehensibility were first examined and evaluated. Furthermore, the assembly was assessed in terms of effort, risk of injury, risk of misuse and damage to the vehicle. Criteria for loading were the height of the loading sill, the opening width of the roof box, the force required for opening and closing as well as the quality and effectiveness of load securing.

Driving safety & crash

The City Crash was carried out on a computer-controlled acceleration sled. The rearward acceleration of the roof box corresponds to an accident at a speed of 30 km / h when driving forwards.

Under this load, the roof boxes must neither lose any load nor disengage from the basic carrier.

Results overview

Model/ Manufacturer	Category weighting	Thule Motion Sport	Kamei Corvara S 390	Atera Formula 980	Jetbag 30 Holiday	Cartrend Krono 480	UltraPlast MD15 350L	Mont Blanc Space 450E
Ave. price
Volume		323l	384l	333l	308l	345l	291l	392l
Usable length		176cm	179cm	176cm	178cm	185cm	181cm	181cm
Layout	40%	1,6	1,2	2,4	2,6	2,3	2,7	1,7
Handling	40%	1,4	1,8	2,0	1,9	3,0	3,3	2,3
Driving safety	10%	1,1	1,1	1,0	1,4	1,4	1,4	1,0
Crash safety	10%	2,0	3,5	2,5	2,5	2,5	4,5	5,0
Overall rating	100%	1,5	1,7	2,1	2,2	2,5	4,0*	5,0*
Criteria: Processing / Risk of injury, Tightness, Cold resistance, Volume *Devalued due to poor scores in crash safety
Note limits: • 0.6-1.5 (very good) • 1.6-2.5 (good) • 2.6-3.5 (satisfactory) • 3.6-4.5 (sufficient) • 4, 6-5.5 (poor)

Results

The current test winner is the Motion Sport from Thule. This high-quality and compact roof box proved itself in the test no weaknesses and convinced in handling, in the leak test, in the cold resistance as well as in all safety tests.

The safety criterion "City Crash" separates the wheat from the chaff. Two roof boxes showed clear weaknesses. The Space 450E of Mont Blanc broke even completely from the test setup, so that they could only be rated as "poor". The model MD 15 350L from Ultra Plast was rated "adequate" in the crash, as both belt systems were broken and a breakage of the roof box also favored the discharge of the cargo. But even the overall good roof box from Kamei was not flawless in the crash: the charge was indeed kept completely in the box, but reached the mounting bracket to secure the load their load limit. Therefore, Kamei did not make the top ranking in the test.

When it comes to vehicle assembly, the Kamei roof box is characterized by the innovative Click Fix System. The system is the only one to use the T-slot of an aluminum roof rack, which, however, requires such a carrier. In the other roof boxes, the attachment is achieved by clasping the whole carrier profile in different ways. Handling advantages are provided by Thule and Atera boxes, which are equipped with a variable length-adjustable quick release mechanism with automatic torque limiter. The somewhat aged use of U-bolts, which are bolted from the inside to the roof box, can be found at Cartrend and Ultra Plast. The disadvantages are obvious: During the initial installation, the holes have to be drilled, depending on the position of the box.

While loading, the Kamei Corvana S 390 impressed again. The geometry of the roof box and the flat design of the fasteners ensure that the entire cargo can be loaded without any problems. In the other roof boxes, either the overall height of the fastening systems (Thule, Atera, Jetbag) or the flat, sporty design in the front area reduces the usable height (Atera, Cartrend, Ultra Plast).

Annoying: The volume of roof boxes cheat some providers. Three models are negative here: Cartrend's model is 12 percent, Atera's model 13 percent and Ultra Plast's model 17 percent less.

Positive: None of the tested roof boxes showed any abnormalities during the ADAC avoidance test or full braking from 100 km / h.

Recommendations after testing

• The mounting systems must be stable enough and should also hold in a city crash at 30 km / h.
• There is a need for the simplest and safest installation; Each roof box should also be mountable by a single person.
• Attachment points in the roof box for the cargo must be available in sufficient numbers and designed for the loads occurring in dangerous situations. The same applies to the load securing equipment. Breaking lashing and tearing straps are unacceptable.
• Even in the cold, all components must be unbreakable
• The volume must be correct
• The correct securing and distribution of the load in the roof box must be clearly indicated in the instructions for use. Cargo securing devices - including any foam rubber rollers - must be clearly specified or included
• It must be clearly indicated in the instructions for use on a changed handling with a roof box