Yup the frame was toast. There was an issue with the first batch apparently, I thought mine was second generation but it must have been one of those early models. Luckily the crack was at the point on the seat tube where Yeti had positioned a load bearing sticker which allowed me to continue riding for the last six weeks....
In other news it looks like the top of the left seat stay was also unhappy, although it hasn't shown up the in the photo very well.
Anyway, it gave me a great excuse to strip the whole frame down and clean everything. New cables, repacked the 240 freehub (almost silent now), and I also got the steerer tube cut so I can ditch the spacer.
I had a bike fit recently and have changed the 90mm stem to a 70mm which has improved my back issues significantly. They have also lowered my seat height by 1cm, so I'll have 13cm inside the frame with a 400mm post, hopefully that will help too.
The only other changes have been the newer Ashima rotors (68g) which are even lighter than the last, unfortunately Virgin Airlines managed to write the other ones off. Bike is sitting at 9.3kg and other than carbon wheels I have nothing left to change without reducing reliability.
Thanks to Yeti for great service. They very kindly shipped the replacement frame whilst I was still riding the old one so I wouldn't get too fat.
