I had another look at your photos and only just realised that you have a lot of blown highlights - pretty much in every photo. That's something to watch out for when you're shooting because although it can be fixed in post-processing to some extent it's usually harder to correct over-exposure than under-exposure.
What exactly are blown highlights? And also how would I fix that?
Blown highlights are areas of extreme brightness which have gone 'off the scale' of whiteness which results in loss of detail in the areas which are too white. In this case most of the clothes the riders are wearing are blown out.
If you look at the histograms
of the above images you will see a spike at the far right of the graph.
You can either prepare for them at the time of shooting by slightly underexposing the scene and then boosting the dark areas in post-processing or fix them afterward. In photoshop, for example, an easy way to recover the blown highlights is to go to image > adjustments > shadow/highlight. Bring down the shadows slider to return the dark areas to normal and then bring up the highlights slider to rescue the detail. Play with the tonal width and radius to get different results.