I know this because I've been puzzling over how to make the rear gearbox mount more rigid. I suspected that having 2 parallel bars would be susceptible to the parallelogram effect - when everything skews over to one side and puts the whole thing permanently out of kilter.

Anyway, a trip yesterday in the Hillman tourer included a commentary from Learned Counsel about the amount of movement in the chassis he was observing through a hole in the floorboards. The movement is fine - it's like an aircraft's wing, it can shake and flop about as much as it likes as long as it goes back to its original position afterwards. So, as I was welding the plates to the saddle,

I was pondering whether or not to weld joining straps across the top and bottom of the plates. I stopped for lunch and opened a can of mackerel.  Bit of black pepper, salad, couple of toms, some beetroot and a dobble of mayonnaise; delicious. On my return to the workshop, it struck me that there was a simpler and much more effective way of stiffening the cross-member,

join the ends.

Now I know how Archimedes felt when he jumped out of the bath and tripped over a loaf of sliced bread. I expect he ate a lot of fish....., livin' on a small island........., near the sea.........., stands to reason dunnit........, s'not rocket science.