Replacement top pad for Alpinestars S-R10 helmets, available in two sizes. Official Alpinestars replacement parts. When selecting your top pad, keep in mind that the same top pad can be used for sizes from XS to XXL. The standard top pad is size 15. If you prefer a tighter fit, you can choose the crown pad in size 20, which is 5 mm thicker than size 15.