Last week, I have received the C4 hub, bearing and axle parts (thanks Jac Mac for your e-bay links
). The first stat I do is strangely, the C4 wheel bearing (double row spherical rollers with angular contact) is integrated with the hub (see picture 1). So I have to follow Rick Lake's idea and to go to the workshop to machine the C4 hub in order to adapt my classic tappered Timken bearings. Then, I have draw a special coupling arrangement to adapt the external Cobra hub to the internal C4 hub (not so easy to do it). Next step I stat that it was impossible to introduce my 1-1/2" socket inside the Cobra hub to tight the big C4 axle nut. So I have to reduce it from 1-1/2" to 1-5/16" to allow a free access to socket. As I had reduce the nut size, it was necessary to reduce the cap in charge to secure it. Then, when I was able to tight the central nut, I discover that the nut was too thick to go until to the hole pin (and the C4 axle was not long enought to add a new hole). This problem because I had an extra thickness with my double hub sandwitch. So I have to reduce the big nut thickness by 5mm. Also it was necessary to reduce little the C4 axle yoke to have a good clearance with my cast aluminum hub carrier (see picture). Next week I hope to be ready to install everything... and to be able to do 1000 miles at least without problem