At the end of the first post in this thread I'd just come across this unorthodox engineering solution...
I also mentioned that the guy I got the bike from had offered me an XR frame he had as a spare. I was secretly hoping this might be a straight swap-in
. Well, I'm not sure what year or even size XR the frame was but there was no chance of it being an easy swap, it was from a totally different era. However, I did spot a likely looking piece of tube with mount holes already welded in that I could repair my own frame with. In terms of welding, these 'cross tubes' were always going to be the hardest part of the job for me to get oil tight.
That's as close as you want to get to my shoddy welding! Even from this distance you can see why I was eager to save myself four more-awkward welds
The mounting holes on the inset tube are 10mm closer together than the original XL head mounts so I'll have to make some new ones, but some progress has been made.
Back to the engine...