The wheelset was a previously unreleased model from Shimano, which the Belgian team Alpecin - Deceuninck has already been in action this season. A team mechanic revealed this to the TOUR reporters on site. The difference to the C50 wheel from the Japanese component giant's Dura-Ace collection, which is usually in the frameset of Mathieu van der Poel & Co, is a slightly wider carbon rim.
There wasn't really much to recognise about the completely black wheels. The only indication that the set was a prototype was on the rear wheel hub.

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