KIF Trior spring size

[mrkrsl]

The KIF spring on the balance cock of a Lemania 1275 crumbled due to corrosion, meaning I need to replace it. I can't find a technical spec of the movement, however, so I'm relying on my own measurements.

Cousins list many. I'm sure I need a type 1 (the Trior) but there are 3 sizes. Reliably measuring the broken one I have is a challenge. But I can measure the bottom one, which I believe to be the same size and by my callipers comes in at 1.75mm. The trouble is none on the list are this size. (See image from Cousins)

Further the chaton diameter measurement (of the shock jewel) measures at 1.35mm on my callipers. Not even close to the measurements on the KIF graphic, which I assume are for a different part of the chaton.

So, I'm doubting my tools, the century I'm living in and also my French. Any thoughts on what I might do to divine the correct part? Or is it a matter of sourcing a second-hand balance cock rather than ordering new?

In short, help! And thanks.

[grsnovi]

Bestfit #111 shows 12 categories of KIF springs on 2.5 pages.

[mrkrsl]

Thanks. That's a great resource (I found a copy linked elsewhere on here) but only a subset of the Incabloc versions of this Lemania chrono movement seem to be listed. (1280, 1281.) The KIF versions (mine's a 1275) aren't listed in there. So, still searching.

[mrkrsl]

An update, should anybody need to know in the future. This calibre, the Lemania 1275 works with the 1-4 KIF Trior springs (top and bottom) – that's the 1.65mm version in the image in my opening post.

I bought a micrometer in the end and managed to get a close enough measurement of the existing spring to take a punt on the right size. These KIF Triors are the fiddliest little rascals to install though, I can tell you. I missed Incabloc while installing the cap jewels, I must say.