Thanks Blazing Pedals for the comment re the sport contacts. I usually carry a pressure guage, so will be keeping them at 85psi (the rated maximum). You and I seem to have slightly different version "sport contacts". Mine were made in India, and have no reflective tape.

I've just noticed Schwalbe have put out a fancy new tyre called a "duro plus". Looks interesting, they claim it lasts for ages, and there is none of that pointless tread of the marathon plus. But as usual not available in 406mm though