is for asymmetry

Still no new hub in the post, so instead of building a new wheel I hacksawed a chunk out of the old one to see what it looked like in section where the rim had bent outwards. It might be clearer after a bit of filing. It's entirely possible that some of the evil red grit distributed over the winter (and still causing punctures where it's worked its way into tyres to lie dormant for a few weeks) found its way under the brake shoe and scored a line along the edge, quickly weakening it enough to enable it to crease without it being thin enough to bend right out of the way and allow the tyre to blow out. A lucky escape, anyway.