First components for Hossack forked VT500ED FF

It will be a long slow process, but I'm going to try to document the building of my FF machine on this page.

The machine will be built round a folded aerolam tub, with a cradle under and partly round the engine, continuing into a triangular cross-section box containing the fuel tank and carrying the seat, sweeping up at the rear into a backrest bulkhead, with the swinging arm pivoting at the back of the central box. A tunnel will be formed through the box containing an extension drive shaft. The machine will be about 10 inches longer than standard.

The first two drawings attached show the Hossack style front fork, and the main aerolam spar of the fork as a developed sheet ready to be cut. The drawings are all but finished, and will shortly be going for quotation for NC milling with an old client who has machines capable of cutting the job. It is possible to cut four sets of uprights from an 8x4 sheet of material, so I will have three spare sets that I may offer to the group.

I've worked out the brake arrangements now and added the single caliper I will use in position on the fork in the main drawing. Mounts for twin calipers can easily be incorporated in the other uprights as they are cut. I also realised that the area between the legs at the top, which corresponds roughly to the position of the triple trees in a conventional fork, is a big empty space that I can use to incorporate a much stronger cross bracing box as now shown in these drawings, complete with a glued in bulkhead component to reinforce it.

Body work will be formed over foam armatures glued directly to the structural tub and skinned in glass. As a matter of simple practicality, the bodywork will follow the Voyager layout, but the foot boxes will extend further down the tub, requiring outriggers to be fitted. If I can do it, I will make a plastic screen and roof, with no supports apart from a substantial rollbar directly behind the driver's head. I 've seen a suitable set on a scooter that parks outside Ipswich station each day.

The fork will be glued up with Araldite 2005 as follows...

First the central rectangular area folds up into a box section, wrapping round the central bulkhead, with a double skin overlap joint in the middle of the long rear face; then each leg is folded over onto an 18mm thick structural core, and the open edges are sealed with carbon tape. Then the two legs fold over, so that they sit at right-angles to the central box section, with the various tabs slipping into corresponding slots, and a pair of large diameter aluminium bars and caps are glued and bolted through at the rear of the upper part of the fork. Standard BMW telelever bottom ball joints will be screwed into these bars to pick up two wishbones.

The mudguard will be a structural component, bonded to the main fork.

Ed Form

honeycomb-hossack.pdf172.41 KB
aerolam.pdf57.19 KB

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Progress on hossack suspension

Hi, how is this going? Have I missed any enteries? as I don't seem to be able to find anything further on this subject. Any photos of development available?

How did it go with your project.

How did your project turn out? Let see some pictures of it. I am very interested in doing the same one day. So let us know of the entire problem that came with it. Even if you did not finish it. It all helps the next person with the same idea.