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Asked around on Fugitive forum about best way to make cycle wings that don't shake apart. This is a big problem for "seven" owners too, the mounts eventually break due to metal fatigue from the vibration.
The rule of thumb is that (ideally) you should be able to sit on the mudguard without it bending.
If you take the drum off there are 3 bolts that run through to back of the brake backplate. I have ordered 6 of these but 2cm longer. Plan is to make up some steel plates that fit over these bolt ends and are then held in place by nuts on the back.
I have done this but quite complicated shapes as have to have holes in the plates to allow tweaking of the brake adjusters, and also to allow you to reach the bolt head that holds the wheel cylinder in - in case you ever need a new one.
Having bolted these up as a test, the plan is now a hybrid affair: bolt plates in to the 3 available bolt heads, then weld the plates to the brake backplates around the outer edge (if done carefully this means my carrier plates for the cycle wing mounts can be removed by just grinding these easy-to-get-at welds and then unbolting).
Vertical parts of wing mounts are in 1 inch box section but with 3mm thick wall. Have been cut and shut to curve around wheel/tyre (sort of). Plan then is to weld very thick metal strip to the angled ends of these which will then curved to run under the fibreglass mudguard.
 Right hand plate bolts to the 2 bolts at rear of hub. The one to left of it bolts to single bolt in front of hub.
The 2 plates for the other side are shown half-finished and the wing mounts for the other side are ready to be welded to the plates.
 Some cutting and shutting of the box section to curve around the wheel / tyre.
 View of extended bolts from above.
 Side view of 2 of the extended bolts (one at front and 2 at rear).
 Painted in POR15 ready to bolt on. POR15 is something I used years ago on another car - it is almost impossible to get off. If you get it on your skin it has to grow off. I spilt some on the handles of a pair scissors I use every day about 5 years ago and it is still there. Apparently it is unstable in UV light (discolours) so you have to paint over it.
 Front and rear cycle wing brackets bolted on. They seem pretty rigid even without the planned welding around the edges to the brake backplates.
I will see how well they work like this before deciding whether to weld them as well or not.
 View from above. Thick flat metal bar will be welded to the slant-cut ends and be bent over tops of wheels.
If that doesn't work I can easily cut the welds and try something else.
  I am using cup head bolts with rubber tap washers above and below the fibreglass to spread load from bolt heads slightly. Using thick wall rubber hose in 1cm lengths as spacers between the metal tabs and underside of the mudguard so no part of the mudguard touches metal at any point - trying to reduce rate of appearance of stress cracks.
 Now I just need to fill in all the "extra" old holes in the mudguards with fibreglass.
 Headlamp position changed again. Now they just miss the cycle wings and the bonnet can just about be lifted off without needing to turn the light pods. Mudguards still need painting but holes glassed in now. |