OK. The bike is 2009 and there is no lifetime warranty on my frame. I won't be getting a replacement any day soon.
I will continue to ride it and see if the crack increases (of course it will) until it is no longer safe to do so.
I like the suggestion of drilling two holes and welding, and the sooner I do that the better.
I will check the seatpost length at the weekend. I was planning on getting a new bike next year so if I can make it last the year I will be happy.
I can probably get a replacement frame on
ebay for not too much so I will keep an eye out.
I have replaced every component on the bike over time except the handlebars, stem, and brifters. Everything else has been upgraded or died over time.
The bike has lasted 9 years and has some about 25,000 miles so I am not at all disappointed. I might even hang it on a wall!
I would have liked to have kept it as a winter bike, it is ideal. I have a steel winter bike already though. Need a bigger garage!