The chainrings on the Ultegra crankset were worn and needed to be replaced. Rather than buying new rings I just replaced the whole crankset. Also these Ritcheys are compact and even use the same octalnk bottom bracket. I think I'm likely to benefit more from the lower range the compacts give me. I don't think I've ever gone fast enough to efficiently use 53x12 with the standard Ultegras. The Ritcheys are also like 90g lighter, not that I care and IMO look way more badass