I tried 25mm GP5000s on my 2005 Madone 5.0. Front fit so close it would pick up pebbles and jam them under the fork crown. Wear a groove in the tire. This was tires bought well over a year ago. Bought 23mm tires too. They were also close. Bought 23mm GP5000s last fall and they were narrower. So there was a change. Also I have 19mm inside width rims. Not original so that spread and made the tires taller and wider. If all else fails I buy one tire to test.