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Alpinestars Nucleon Back Protector Insert
  • Alpinestars Nucleon Back Protector Insert
  • Alpinestars Nucleon Back Protector Insert

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Alpinestars Nucleon Back Protector Insert Videos

Alpinestars Nucleon KR-2i Back Protector Insert


  • CE Certified Level 2 (EN1621-2:2014)
  • Lightweight, flexible PU injected impact foam
  • Contoured for anatomical and adaptive fit
  • Perforated for breath-ability and comfort
  • Channel ventilation system for optimized airflow

Note: Size MD is recommended for Men's jackets size 50 and smaller and XS-MD. Size LG is recommended for Men's jackets size 52 and larger and LG-4XL. See specific Women's jackets for sizing recommendations.

Sizing Info:

Waist to Shoulder (in) Height (in)  Protector Size
15 - 17 56.75 - 64.25 SM
17 - 19 64.25 - 71.75 MD
19 - 20 71.75 - 76.5 LG

Product Style RevZilla Item # Manufacturer Product # Availability
SM 973533 6501615-10-S In Stock: Ships within 24 hours
MD 973534 6501615-10-M In Stock: Ships within 24 hours
LG 973535 6501615-10-L In Stock: Ships within 24 hours


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If your order arrives and it is not right, we will we'll fix it, NO NONSENSE, we promise.

Doesn't fit or just not happy with it? You can return any new, unused and unaltered item within 30 business days of delivery receipt of your item. We will issue a full refund to your original payment method.

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Alpinestars Nucleon Back Protector Insert 4.8 5 58 58
Just what I was looking for I purchased this as an upgrade for the flimsy piece of foam that came in my Sedici jacket. It fitted perfectly without trimming. Haven't ridden in it yet, but it molds to my back and feels comfortable to wear. Hopefully all the air holes will keep it from being too hot. April 19, 2016
Flexible Breathable and Thin Protector is everything that is advertised, it was actually thinner and more flexible than what I was expecting it to be. To me the small size and flexibility make it worth the price. April 14, 2016
Great for AStars GP Plus R Perf jacket Was worried it would add heft to the already tight jacket but it really doesn't. I think the KR-1i would since it has a plastic housing on top of this one. Very flexible which is great as it conforms to your back when tucked. Can't vouch for the protection but judging by the specs it will hold up just fine.Thanks Jeffrey P. for helping me with the decision. April 8, 2016
Seems Durable, Forgettably Comfortable I have had the fortune of not having yet tested the protection, but it's way more confidence inspiring than a little comfort foam, at least CE thinks so. You really do forget it's there when you ride, both with and without backpacks. March 23, 2016
Good, Stiff, Back Protector I ordered this back protector to fit into an Alpinestars Viper Air Textile Jacket. It fits perfect. This back protector is very substantial and I think it would be quite protective if needed. However, it is very stiff and does not readily conform to the curve in the spine. It is also thick so it makes snug jackets feel even tighter. Obviously this comes with the territory of being a Level 2 protector. In retrospect a Forcefield back protector (level 1) may have been a better choice. March 20, 2016
Perfect for Alpinestars T-Jaws Air Large size fit perfectly in my large Alpinestars T-Jaws Air jacket. Fairly slim insert but it does make the jacket a bit more snug. March 2, 2016
Great upgrade! I bought this to replace the foam in my Joe Rocket Phoenix 5.0 jacket. Great upgrade! It feels lighter and more contour to my back than the foam that came with my jacket. I dont even notice it's there! It also seems to make the jacket fit better, closer and feel less push when riding at highway speeds (think it's due to better air flow from the vents on the protector). Can't speak for the protection (and hope I never have to, although if I do then that means I lived to tell the story, which isn't so bad), but it feels tougher, malleable, and better quality than the foam that was in there before. Overall, I'm very happy with this purchase! February 10, 2016
Alpinestars Nucleon Back Protector Insert; thumbs up! Bought to replace the (worthless) pad already in my Alpinestars jacket. It's worth the money and you forget the back protector is there after a few rides. January 19, 2016
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