First of all, the true parabolic tapering of the spring. This tapering is in a true parabolic way to
assure maximum force distribution and transfer from the ends to the middle section. This gives the best results in both comfort and
long time.
Second, the number of leaves. The front springs have only two leaves instead of nine or eleven. The rear springs have three (load level B) or four (load level C & D) instead of ten or eleven leaves.
Each leaf is actually a complete spring in itself. To enable maximum
deflection the stress is divided over several leaves
Third, the spring leaves do not rub against each other over their entire length. Instead, the lower leaves are shaped at the ends
and 3 mm spacers are fitted between the leaves in the
center, thus leaving a space along the length of the spring with friction only at the ends.
The advantages
A much improved combination of spring characteristics with the reduced thickness at the ends of the springs provide improved comfort,
whereas the strong central part ensures a very goad load capacity.
Because the leaves are not rubbing together and the outer ends are separated
by PU blocks, the problem of a build up of friction and rust is prevented.
Un-sprung weight is reduced because, for example, the front springs weigh only about half as much as the standard type.