I now have 370 miles on my retrofitted Schlumpf two speed on my Strida 5 - and double that on the retrofitted aluminum rear pulley. Both items are winners, with absolutely no problems and a fast 2 speed ride to work - in weather down to -9C (this morning). No belt skipping here!
I don’t use the heel-kicker plates originally ordered, it has proved very easy and instinctive to shift directly with the heel button (after a few days familiarising).
That contrasts with 364 miles to scrap on the OEM plastic rear pulley (using single speed ratio), on the same commute (13 miles a day total in Vancouver conditions).
It is fun to note the puzzled faces from other cyclists as I speed away from the lights: the 40"/66" gears are a perfect match for my mostly flat but one big hill route with the bike’s light weight and manoevrability.
Congrats to Florian (and Mark) for a brilliant combo.