The Alpinestars Nucleon KR-2 is the top of the range Level 2 CE-certified back protector, designed for adventure touring. I use the full race Alpinestars Nucleon KR-R back protector under leathers, but for the rest of the time – for commuting and touring – I’ve been using this Nucleon KR-2 version, as it’s lightweight and heavily vented, making it cooler and comfier to wear in Thailand.
The energy-absorbing articulated back section snugly follows the contour of its vented waist strap and removable shoulder straps. Like Alpinestars claim, it’s so comfortable you forget you’re wearing it after a while. Build quality is top notch, too. When wearing it with shoulder straps the lower spine section can sometimes push your pants down, especially when wearing zip-together riding kit like two-piece leathers or adventure-style gor-tex. In those cases I remove the strap and let the back protector hand lower. But it’s not a problem when wearing jeans and jacket.