Hello Michael,

I used a R1 wheel because it has a very big hub. In picture 1.jpg you can see the R1 inner hub, that I took out with a hand saw. After that I machined the rim to clean the rest of my hand saw job and make a housing for the disc carriers. I didn't make any welding or bonding on the rim. I made new disc carriers, and they were used to accommodate the big wheel bearings, Hoyt Mckagen gave me this idea (5.jpg).

Like you can see in the pictures, the king pin is introduced into the hub from the top. Between the king pin and the hub there are needle bearings, (radial and axial ones). Between the axle and the king pin there is a steel bushing  if I designed the system again I would use a needle bearing instead of that. The king pin has needle bearings at both sides (4.jpg). Also you can see (14.jpg) that the wheel axle goes inside of a tube, I did that to change the wheel easier (otherwise the needle bearings would fall to the ground everytime you take out the wheel axle).

On 12.jpg you can see that I used a sandwich concept for the vertical arms. I tried to locate the vertical arms as close as possible to the disc brakes, to reduce as much as possible the braking moment that would try to twist those vertical arms. Because they are very close to the discs, they can be very light.

When I designed this front end (5 or 6 years ago) my favourite system was the Difazio one, like you know in this system the king pin / swingarm manages all the side loads that arrive to the wheel. I liked this idea because in that way I could design a very light vertical arms and bridge (13.jpg) that only should manage the braking reaction and the steering forces that you make when you turn the handlebar.  The bad point of the Difazio system is that the king pin is highly stressed.

Now I think that if I some day I make again a bike with a hub-centre steering, I wouldn't use the Difazio concept, I would prefer to use a system with a spherical bearing inside of the hub. In that way the vertical arms should manage the lateral loads, the king pin wouldn't be so stressed and the loads would be more spread into all the front end parts.

David Sanchez