BUSTED!

Here's the bike fully built:

This pics is after returning from a circuit of Richmond Park where the frame worked flawlessly. Not a creak, not a wobble. It was fast. It was fun. It gripped well and rolled fast. And with the lockout on the forks engaged it accelerated like a whippet.

It also felt a bit short in the top tube. I assume my mistake in the geometry was that I hadn't accounted for the extra-low bottom bracket and high head tube when setting the length of the top-tube. With the seat back as far as possible on it's rails the bike feels ok but this is something I'd change if re-making it.

Then disaster. 

After a successful 1st ride I started commuting on the bike. The 1st day was fine. The second day was fine until I was half-way home. After pulling away from some traffic lights the bike started wobbling when pedaling. It felt like a loose crank arm so I pulled over. It wasn't loose cranks. A weld had failed and the bottom bracket was only loosely attached. 

The problem with breaking down with a bike in London is that at rush hour you cannot take a bike on the tube or train so your only option is to push the whole way back! At first I tried to pedal on, very gently - this worked for maybe 100 meters or so before the rear wheel suddenly started to rub the inside of the left chainstay. Stopping again I discovered that another weld had gone, this time it was the chainstay-rear dropout.

It was a long walk home.