I did end up sawing through the shaft of the bolt in the gap between the stem and the body, to remove the aluminium bolts I unwisely used as stem bolts. The slot I’d sawn into the head of the first bolt wasn’t wide enough to take a screwdriver blade.
Before the hacksaw blade had made it the whole way through the shaft, the tension the bolt was under snapped what was left of it and the hex head pinged out of the faceplate like an aluminium bullet!
At that point the other shagged bolt magically loosened itself and I was able to remove it without any trouble. So I’ve binned the old stem. It was a replacement for the original Boardman stem that was far too long. And I’ve put on the stem that came with the X originally, which is 10mm longer but I think it should be fine. I’ll have to adjust the saddle a touch, I expect. But actually it should be closer in geometry to the Cannondale, which really suits me. Might improve the handling a tad as well.
So ignoring inner tubes, bar tape, bottle cages and tyres, the Boardman has now had:
- three stems
- two seat posts
- two front derailleurs
- two wheelsets
- about four chains