1 22 Lt top box air braking cured. Tue Aug 18, 2020 2:28 am
MartinW
Life time member
I had a problem with the lid of my latest top box popping open at 100 Kph. I thought I had sussed the problem being you had to have the lock open for the hook on the lock to engage the latch wire which is true. However on our recent four day adventure the lid kept popping open. In the end I strapped it closed which did temporarily solve the problem.
Today I decided to get to the bottom of the problem and find out why it popped open even when you couldn't open it by lifting on the edge. Using Blue Tack ( plasticine) I stuck a blob in the throat of the lock hook. When closing it the wire latch was only just engaging the hook and while stationary it was secure. However at speed I suspect that a bump could cause it to unlatch due to a bit of play in the locking hook.
In order to get the wire latch to get further into the throat of the hook I had to do a bit of bending on the wire latch inorder to move it further into the throat of the hook. Once bent the wire latch didn't go down far enough to engage the hook so a extended the slotted adjustment holes enough for it to engage. In order to see how much engagement I was obtaining during the bending and adjusting with the wire latch slots I kept inserting Blue Tack into the throat closing the lid and checking how far the wire latch had gone into the Blue Tack. Eventually I got to the point where I was happy with the locking. Plasticine would have been better than Blue Tack as it is softer, whereas Blue Tack being a bit harder requires using different thicknesses and more checks.
Regards Martin.
Today I decided to get to the bottom of the problem and find out why it popped open even when you couldn't open it by lifting on the edge. Using Blue Tack ( plasticine) I stuck a blob in the throat of the lock hook. When closing it the wire latch was only just engaging the hook and while stationary it was secure. However at speed I suspect that a bump could cause it to unlatch due to a bit of play in the locking hook.
In order to get the wire latch to get further into the throat of the hook I had to do a bit of bending on the wire latch inorder to move it further into the throat of the hook. Once bent the wire latch didn't go down far enough to engage the hook so a extended the slotted adjustment holes enough for it to engage. In order to see how much engagement I was obtaining during the bending and adjusting with the wire latch slots I kept inserting Blue Tack into the throat closing the lid and checking how far the wire latch had gone into the Blue Tack. Eventually I got to the point where I was happy with the locking. Plasticine would have been better than Blue Tack as it is softer, whereas Blue Tack being a bit harder requires using different thicknesses and more checks.
Regards Martin.
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1992 K75s