Measuring it like this is not really useful. Keyswitches have quite strange force-displacement diagrams, so just stacking weights on a key will give you just a rough estimate of the maximum force required.
Doing decent measurements is not really easy and involves
a lot of patience. I did three rounds some time back with different keyboards, but haven't gotten around analyzing the results and making fancy diagrams yet, so it didn't seem worthwile to publish it. Also, this doesn't really make sense until I've further analyzed the data to determine the error of my measurements, which unfortunately should be quite high.
There's an incredibly high error in measurments with hacked-together devices, so it's not really usable as a reference. From my measurements, however, activation forces of BS are between 70 cN and 80 cN, which is in the dimension you'd expect. These tend to vary somewhat between measurements, so really measuring forces that small is quite a pain due to incredibly large error.
Doing this stuff properly takes hours per switch; time I currently just don't have. The measurements get more refined every time I do a new batch from what I can tell, but the error is still too high (probably, I haven't even calculated it yet) to take this as a reference. I didn't have any linear switches at hand, so this was not linearized or otherwise cleaned up properly, which really should be done before publishing these things. But seeing the topic came up, it was
really tempting. So, without further ado, one of my measurements.
Done using completely hacked-together equipment, so please don't take it seriously. The diagram doesn't even look decent. Labels are in German, but it shouldn't be too hard to figure it out.
-huha