Helmet question

[ILoveCake]

Didn't really know where to put this so I figured this would be ok.
What size should I get in this helmet http://shop.foxracing.com/ecomm/Aut...Helmets&proNumber=01053&imgName=01053008F.jpg
if I wear a small in this helmet (I know it is for bicycles but I am just starting riding and I didn't want to buy a new one right away and I had this one from dirt jumping bicycles) http://www.jensonusa.com/store/product/HE502A00-Azonic+Fury+Helmet+06.aspx

Are the sizes mostly the same for most helmets? Also, does anyone know if the fox one has different shell sizes for different head sizes because I don't want to have it look like a bobble head.
Hope that made sense :think:

 

[mmz77]

I did some conversions through helmet sizing and I am positive you will need a small in the Fox also...

 

[Octane250F]

The sizing changes from brand to brand. My advice would be to go to the local dealer and try on the helmet you are looking at and then go online and order it there if the price is cheaper.

 

[ILoveCake]

Thanks guys