Doing audio when there is a lotto noise is a bit of a challenge. There are things you can do to reduce the noise, but you won't be able to eliminate it. I used to use a Cardo comm system in my helmet. While the audio was very far from perfect, the positioning of the mic inside the helmet did a lot to improve audio and eliminated most wind noise. It feels like there may be a way to mount a mic inside the helmet that is more directional and reduces side noise better. I believe it is the Shure SM35 that @Pete A Turner uses that might work mounted in a helmet. He would know more about how it mounts/connects since he uses it.
Don't overlook overdubbing. Basically taking what you recorded as audio and re-recording it in a quiet environment and replacing the audio track. Some combination of both techniques is what I see from a lot of videos recorded in high-noise environments.
