It provides a progressive and adjustable front suspension.

It copies the terrain very well in the first part of the travel, and it gradually hardens so that it does not bottom out.

The adjustment is done by putting more or less pressure in the cartridges with the hand pump equipped with a pressure gauge.

Because the air cartridge has a progressive behavior, and a spring has a linear behavior.

Springs can be single-stage or two-stage (this can be seen if the coils are closer together in one part). These springs are not progressive, but two-stage. HFS is truly progressive because it is based on the behavior of air as a gas.

HFS does not require any specific short intervals maintenance.

The lifespan of the seal system depends on use, and based on tests carried out it is similar to that of other suspension products such as rear monoshocks.

In cases where the bike is not in use for a long period, for example 1 year, it is advisable to confirm the pressure of the air cartridges again.

We have developed a self-maintenance kit so that the user can change or replenish the internal oil. It is normal to have to do this operation after several years of use, or intensive use in competition.

No, it doesn't change. The motorbike will have better front suspension performance, but it won't require any changes in riding due to the system itself.

Because HFS is a progressive suspension: soft in the first part of the travel, and becoming stiffer as the subsidence increases (for example, on bumps or when braking).

It is not necessary. One option, if you want a more retained suspension for strong bumps, is to raise 5 degrees defined by the manufacturer; for example, going from SAE 10 to SAE 15 in Tail, or up to SAE 20 on the road.

Mainly, adjusting the sag when stationary. For example, for the same bike, a rider weighing 75 kg will use less pressure than one weighing 100 kg, to have the same sag. This allows both to take advantage of the same suspension travel. More or less pressure is also used to change the response of the suspension according to the rider's preferences. On classic bikes, there are different springs depending on the rider's weight.

To ensure that the cartridge chamber is as extended as possible. If the pressure is adjusted with the wheel supported, the air chamber will be smaller and even if we have adjusted it to a pressure of, for example, 4 bar, the amount of air we have put in (due to the fact that it is somewhat compressed) will be less.

It is not necessary to do this on a daily basis; in case of prolonged periods with the bike stopped (for example, from 6 months), it is good to check the pressure and readjust. Of course, if you notice a different behaviour, for example softer than normal, check immediately and consult HFS if you have any doubts.

Yes, it is the air in the pump's flexible tube, which escapes when we unscrew the terminal. 

It can happen and is not a problem. It is a small amount that can remain in some very fine holes inside, and that can come out during the pressure checking or adjustment operation.

- PRO: both bars are progressive, for more aggressive riding, it can have a faster extension and present greater resistance to suspension bottoming out in maneuvers with a lot of force on the front end.

- EXPERT: One bar is progressive (cartridge) and the other is two-stage with adjustable preload. It is a very good compromise for competition riding. By having a progressive bar, the whole set is. The 'mechanical' side allows you to adjust the stiffest part to start at two different points of travel.

- CLUBMAN: Both bars are two-stage with adjustable preload. It significantly improves the original suspension because you can adjust the point from which the suspension becomes stiffer, which is very interesting to have the advantages of soft suspension at the beginning, and with good resistance to bottoming out at the end of the travel.