Everything has now arrived bar the 20" rim for the front. Popped the rear tyre on and the Sunrace cassette, it's massive, easily hides the 160mm rotor on the other side. Seems nicely made and reasonably light for the price.
The bit I've been most cautious about is extending the steerer on the fork as i couldn't find a 20" fork with a long enough one. Needed to be at least 350mm (HT is 275mm). Got some 25.4 tube with 1.6mm wall which is a snug fit inside the 1 1/8th steerer on the fork to use as a plug. Cut that to approx 300mm. Malleted it right down til it hit the bottom of the crown on the fork, so about 180mm of insertion. Then drew plenty of brass down between the two, similar to brazing a lug. Then malleted an additional piece of 1 1/8th steerer onto the exposed bit of the plug. It was a nice tight fit, then fed more brass into that half of the join and filled the gap made by the bevel of the two tubes with more brass. The combo of a really long plug, lots of brass pulled into the join and the really tight fits between the steerers and plugs has given me a reasonable amount of confidence that it's strong enough. It's also dead straight which is good. Just have to wait and see if it snaps in half..
Genesis: