I have 8000 miles on my ST 1 and my original tires are starting to show wear. I am amazed and confused with all the different Schwalbe tires available for ebikes. Race Guard, Green Guard, Performance Guard, Marathon, Marathon Plus. I ride hard surface only and in the mountains the descents can approach 45 mph so I'm looking for a tire safe for ultra high speeds. I'm not overly concerned with puncture resistance, have used "slime" when I have flatted and it so far has got me back home. Any recommendations will be greatly appreciated.