I know it’s not the correct way to do, and it stems from my experience driving, but I’ve always used the first digit in the speed limit signs for bends/corners

I know it’s not the correct way to do, and it stems from my experience driving, but I’ve always used the first digit in the speed limit signs for bends/corners on mountain roads as a guide for the gear to be in. 25mph curve? Whatever speed you can do in second is fine. 45mph, fourth gear speeds, etc. Not entirely related but yeah, depends on road conditions and signage.