After staring at their CAD rendering and also a couple of the pictures from their patent for a few minutes, I understand how their mechanism works. I will try to describe it to you.
The relevent US patent is 05971877.
Explaining the mechanism from the axle outwards, and neglecting literaly hundreds of bearings, we have:
1. A fixed axle and associated torque arm. They don't clearly show the torque arm in their diagram, but it must be there and it wouldn't be very interesting if it was. The axle is eccentric in the middle section, standard in the portion that joins with the frame. The axle only moves when your torque arm rattles loose and beats the hell out of your rear triangle.
2. One Eccentric sleeve with engages the axle in the portion where it is itself eccentric. This is reminiscent of an eccentric bottom bracket. By turing this sleve relative to the axle (By having the stop for a boden cable on the torque arm and the cable clamp on the sleeve), the amount of eccentricity of the outer diameter of the sleeve can be changed relative to the axis of the axle. The sleeve only moves when you shift "gears", and it does so continuously rather than being indexed.
3. Four pawl holders, which are concentric about the outer diameter of the larger eccentric sleeves from (2). They do not engage with anything except the pawls they are holding. Each pawl hoder has two sets of pawls oriented in opposite directions.
4. Pawls. Each pawl is held in by a spring mechanism, rotates about the end in the pawl holder, and has teeth on the outside, which engage with (from chain side to drive side):
5. An outer toothed ring that is fixed to the rear cog.
6. Three more toothed rings. Each toothed ring engages with two sets of pawls, one from each pawl holder. The two sets of pawls associated with each toothed ring are oriented in opposite directions.
(Parts 3 - 6 are all moving whenever you are pedaling.)
7. The hub shell, which engages a single set pawls, i.e. the leftmost set. This set of pawls freewheels when you are coasting. The hub shell rotates axially about the center of the axle.
To understand how the pawls work, imagine a very flexible person standing on skis that are parallel, one slightly forward. Now assume said person passes out. Gravity pushes said flexible person down and he/she does the splits, pushing one ski forward and one back.
Analogy:
Gravity <--> Eccentric sleeves acting as a cam relative to the hub shell / toothed rings.
Skier <--> Pawl Holder
Pawls <--> Legs
Skis <--> Two adjacent toothed rings
So on one side, say the front, of the hub you have pawls engaged with teeth and expanding, and on the other side, say the back, you have pawls contracting and engagine with new teeth. The more eccentric the outer diameter of the outer sleeve, the farther down the pawls "squish" during each cycle.
The design does have some elegant properties:
- You don't have to change the dimensions of any of the parts relative to each other to change the gearing range of the hub. This is in contrast to the much seemingly difficult to design and dimension gears in a traditional gear hub.
- While there is a rediculous number of parts, there are not really very many types of parts.
- It may not be as difficult to service as it seems; It seems like each pawl holder and associated two sets of pawls stays together when you pull the mechanism apart.
- I could imagine it being very smooth when in good working order and at lower speeds. I imagine the pawls whining a bit at higher speed, i.e. not when they are engaging, but when they are slipping to new teeth.
- It is, IMHO, easier to understand than a rohlhoff.
- Does not rely on friction like many other continuous gearboxes.
So no, they don't seem to be a hoax, yes, it seems that have a workable mechanism, and no, I wouldn't recommend buying one until they bring the price down by a factor of ten or so and hire a competent marketing department.