The mirror mounting proved to be problematic:
Disaster!
Catastrophic failure of one of the b-Twin mirror stalks, just below the ball joint where the stress is greatest:
Complete arse to photograph, as it's tiny and hard to get the lighting right without proper gear, but the metal has sheared right off. We were proceeding along a perfectly reasonable stretch of smoothish tarmac at the time, and it hadn't been bashed recently or anything. Looks like there might be a manufacturing defect, but it's hard to tell.
That happened a second time (
after I rolled the trike on a canal towpath), so evidently not a one-off failure.
The mirrors themselves are optically ideal, but something stronger was needed for the mounting. Extensive googling revealed that the magic words are "ball stud" (though some fine-tuning of search parameters may be necessary
).
Strong 8mm ball studs seem to be a common piece of gas lift attachment hardware (think car boots and the like), so I was able to obtain
some with an M5 thread from a SGS Engineering. This fits the existing socket on the back of the Decathlon mirror.
In the interests of working mirrors I obtained some 100mm zinc plated steel corner brackets from the local DIY shed, though obviously alloy would be preferable for weight reasons:
I drilled out the holes to appropriate size, cut one end down to form an 'L' shape, and gave it a few coats of black spray paint:
Closeup of mounting: M5 bolt, washer, bracket, piece of inner tube, mudguard stay, penny washer, nylock nut. This is pleasingly secure, but I kept the cable tie around the top of the bracket to prevent rotation if bashed.
To recap, the mirror is one of these, £5 from Decathlon - we're now discarding all the supplied mounting hardware:
Here's the rider's
eye shoulder view:
And from the front:
The 'L' is pointing inwards, so the mirrors are slightly inboard of the previous position. This means they're no longer the widest point of the trike, but doesn't seem to affect the view.
It's had one test ride so far, but in conditions where barakta could barely see what was going on in front of her (dark, wet), so all we really know is that they're reasonably pothole-proof.