Just to clarify the 24.4 measurement was without any pressure from the stem bolts in its open position. Entirely possible it could close up a couple more mm but I didn’t try.
It’s now measuring 25.2-25.4 in its open position but would need to be slightly more to slide over a 25.4 bar without having to use force , or twist a bar through.
I have fitted a scrap 25.4 bar to it but wouldn’t try to scrape a nice NOS hyperlite through it.
For reference I’ve another 3 Syncros stems which measure 25.8 - 26.1 when open. And likely could be pulled wider if needed but happily slot over any 25.4 bar.
View attachment 966236