When carrying out some recent work on my bike (removing the topbox and associated plate I noticed that all was not well - plastic wise
This was what I was presented with on both sides of my pillion seat. A crack 50% of the way through both sides.
Now I believe this was caused by two factors working against me 1) the weight that I regularly carry in my topbox (approx 10kgs) and 2) the amount of bounce that the topbox experiences.
Whilst the topbox was mounted correctly I always had concern that the mount was on top of the rear grab rails and as such was "sitting on rubber". This in my opinion results in a flexing of the topbox. - This had been pointed out to me by other riders travelling behind me.
So here is how I fixed it - not cosmetically great, but structurally sound.
I applied a small amount of epoxy cement to the cracks.
I then fashioned two small "L" brackets out of metal and pop riveted the brackets to the underside of the cracks.
I let you know how it stands up over time.
A.