I was hoping someone else would answer so I understood the question!
I can't work it out, it's surely going to depend on wheel, tyre and guard sizes? On my Nomad, 61L (But frame size won't make a huge difference) 650B wheels, 50mm tyres, 65mm guards, the seat stays just above the guard are 105mm centre to centre and 90mm inner edge to inner edge. For my bike, any frame lock that accommodates the tyre and guard, is going to fit fine on the stays. The measurement that for me is most critical is the drop, I had to lower the guard a couple of mm on my E-bike to get a frame lock to fit, otherwise the bar would scrape the rim.