I'll be brief, as this is a simple question that's been on my mind for the past couple of days. How fast did you guys manage to go on the SP2 railway tracks?
I've been wondering since when I tried to use one of my trains, a 200km/h tilting train to be exact, it always derails when going over 100km/h. And I'm not the only one, apparently; all the SP2-compatible trains I managed to find on the site seem to be incapable of speeds greater than that.
Granted, I didn't see many high-speed trains being adapted, but who knows?