I am after a L series lens for my 7D body to use while taking images at various rounds of the MX Nats, club motocross days, AORC rounds and for some portraiture in between. I have spent a fair bit of time looking at the 16-35mm f2.8 L II USM as it gives me a great wide perspective. I know it's fast and the picture quality would be typical of Canon glass but is it the right zoom combination for that type of photography?

I don't want to go and spend big money on a lens that isn't the right one.

Can someone help me out with this?