While they can be fast when asked, their primary focus is on grace and style, making them not typically used for racing.
It's difficult to give a specific speed for a Saddlebred horse as it depends on the individual horse and the type of gait. However, they are not built for sprinting, so they likely wouldn't reach the speeds of a thoroughbred racehorse.
If you're interested in learning more about the specific speed of a particular Saddlebred horse, you'll need to talk to its owner or trainer.