Winds are always going to come in on the mic. I've never seen it not for any helmet cam. I can't say any of my videos have been ruined either. Edit out sounds, replace with music. Generally speaking the sounds of you skiing, mountain biking, whatever, make your video suck. Axe it...
How can I reduce this background noise, is there a way of sticking a bit of foam over the microphone on the camera?
A common trick used on the contour's is to put a small piece of masking tape over the microphone hole, what this effectively does is stop the wind from catching at the inlet for the microphone, and while it will still catch some noise, it should allow most other sound through without so much wind.
Try it and let me know if it works please... Always good to find out the result on different equipment for future reference...
And maybe Baconzoo will see this and have some advice to answer your question directly. Since I don't have a Ghost I can't say if you can turn the mic off or not. Again though, any decent video editing software should make it super easy to remove the sound recorded with the video.
I don't want to lose the engine sound completely, I've just reduced the sensitivity of the mike to minimum and will try it this weekend. If that doesn't work, I'll increase sensitivity but cover the mike.
Here are the videos I was talking about, both are quite boring although there are falls at the 6.00 min in the first and at 2.20 and 16.20 in the second.
Seriously ditch sound for the most part. Edit your clips down to a song or two at most. Unless you are some super bad ass like xavier, travis rice or our very own cro_reps, you are not going to hold our attention for that long. Put in the best edit out the rest.
Recorded sound only works if you got something funny or gnarly.