The previous Fizik Uomo R1 shoes, with its carbon ratchet was a beautiful and supremely comfy shoe, but it had a few issues. Namely they were really heavy and had an upper that was far too soft, meaning that they weren’t very efficient when sprinting. The old R1 was a great shoe, just not ideal for racing and most Fizik sponsored professional riders chose the lower model, the Fizik R3B over the original R1.
Read more at http://www.cyclingweekly.co.uk/reviews/cycling-shoes/fizik-r1b-uomo-shoes#4wYSBvPYQ0B5vHG3.99