Load capacity
The maximum weight that is allowed to be carried on the boot.
It is definitely not worth exceeding this parameter — even if the structure does not break immediately, this can happen at any time due to off-design loads. And ideally, you should have some margin for carrying capacity — this will give an additional guarantee in case of emergency situations (like hitting a wheel in a hole at speed).
Also note that the weight of the intended load must be supported not only by the boot itself, but also by the crossbars on which it is installed (if this installation option is used, see above). Moreover, the weight of both the cargo and the boot falls on the crossbars, which requires an even greater margin for load for them.
As for specific carrying capacity indicators, in general, the indicator
up to 50 kg is considered relatively low,
51 – 75 kg — average,
76 – 100 kg — above average, and in the most "heavy" models, the permissible load weight
exceeds 100 kg.
Bicycle mounting type
Mounting method provided in bicycle racks (see "Type")
- Frame. Mount to the frame, or more precisely, to the top cross member of a classic bicycle frame. A fairly simple, convenient and reliable option, which, however, may not be suitable for some bicycles - in particular, models with a “female” low frame.
— Wheel/frame. Attachment to the wheel(s) and frame at the same time. Thanks to additional fastening points, this option provides greater reliability than the frame-only mounting described above. In addition, the design may provide for the possibility of adjusting the fastening to non-standard frames (however, this possibility must be clarified separately).
- Wheels. Mount only by the wheel(s) is quite rare - mainly among bicycle racks installed on the roof. The effectiveness of such fasteners does not depend on the type of frame, however, the device may be incompatible with small diameter wheels.
— Front fork. Mount for the front wheel fork; The wheel itself must be removed. This option is used in some bike racks mounted in a trailer (see “Installation”) - it is easier to place a bicycle with a removed wheel in a trailer/body than a fully assembled one.
Lock
The presence of a
lock in the design of the boot.
Almost all modern boxes are equipped with locks (see "Type"), and in such models the purpose of this function is obvious: it protects the contents from theft and unauthorized access. However, similar equipment can be provided in other types of luggage carriers and even in cross members; in the latter case, the lock is used to prevent an unauthorized person from removing the rails with the boot installed on them. Anyway, the presence of a lock provides additional security.
Also note that theoretically, the lock can be any (coded, electronic, etc.), however, in fact, classical devices that are opened and closed with a key are most often used.
External dimensions (LxWxH)
Boot dimensions in working position; usually indicated for open models and boxes (see "Type"). The capacity of the product directly depends on this parameter, in particular, its suitability for transporting large items. And in the case of boxes, dimensions also affect aerodynamics: increasing the height or width increases drag and fuel consumption. At the same time, it should be noted that the aerodynamics of the container also largely depends on its shape.
For open boots, the height is most often not indicated — after all, its actual value usually depends not on the dimensions of the structure, but on the size of the cargo being transported.
Weight
Net weight of the boot in working (fully assembled) form.
The light weight contributes to fuel economy (especially during long-term use) and also makes it easier to transport the boot outside the car (for example, from storage to the car and back). On the other hand, lightening the product leads either to a decrease in its strength and load capacity, or to an increase in cost. So in certain situations, a relatively heavy boot may be the best choice; and when choosing a light model, you should pay special attention to the claimed load capacity.
