I'd use an adjustable reamer to ream the stem from 25.4 to 26.0. I did this back in the 1980s when I wanted to use 26.4 Cinelli bars in a Nitto Technomic stem. The adjustable reamer I have for seat tubes has enough adjustment (down to 23.75) to be used for stems as well.
You can get cheap adjustable reamers off Aliexpress for less than $10. No idea of the quality (probably crap), but they should last long enough to do the job you need on an aluminium stem. Nick Payne -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/9c9e7e4f-99fb-45c2-8ace-3e481fbbd73cn%40googlegroups.com.
