Unusual bicycle front suspension - GIF

[sossol]

The idea of having constant trail is a mistaken one. There are many riding situations that cause suspension movement, if you design for constant trail in one situation then it will NOT be constant trial under other conditions, you may have created greater variation in some.
For example in the design of the unit under consideration here, it looks like trail is close to constant under the condition of pitching forward about the rear axle on level ground. This is close to the braking situation of a bike with no rear suspension, but the situation is completely different if the suspension is moved up due to a bump. Here is a part page from my chassis book, which briefly shows how the trail variation is dependent on the reason for the suspension compression (motochassis.com .

click for full size.

That shows how the concept of constant trail is not valid over all conditions but another consideration is " Is constant trail and/or constant wheelbase a worthy goal"?
The suspension compresses due to increased load on the front wheel, do you expect that the "ideal" trail is the same under different loading conditions. I think not.

I could be mistaken in my recollection. I make no claim on the matter. I prefer rigid forks on my bicycles.

Neil