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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.

See our full Return Policy for all of the pertinent details.

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Alpinestars Nucleon Back Protector Insert 4.8 5 51 51
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
FEELS GREAT! I have this installed in my Alpinestars "Viper Air", textile jacket and have been riding with it for some months now. Although it feels SLIGHTLY heavier than the PE foam pad that came stock with the jacket, it makes the jacket feel a lot more durable. A definite plus. It conforms to the shape of your back, without feeling real "foldable", like the PE foam does, and doesn't have that rigid. .. shifting feeling of the "Bionic" back protector. I haven't "had the chance" to test the durability of it, and I hope I never will, but to me it inspires a little more confidence on the road, knowing that its there. I'm looking to swap out the "Bionic" chest pads, for the "Nucleon" ones in the near future. November 19, 2015
Lightweight This protector is very lightweight and doesn't bulk up on the provided jacket pocket. It is quite vented as well and offers a much better protection than the original thin protector. November 9, 2015
Good option The back armor looks to offer decent protection. Its comfortable because I don't even notice that its there. October 5, 2015
comfortable, good airflow, flexible I bought this product to replace the stock foam in my Alpinestars jacket. My jacket size is medium and I used the size medium back protector and it's fits well. It's comfortable and the airflow is great. October 5, 2015
Great, well priced upgrade with nice protection I bought this for a Vanson jacket that did not have a back protector. I glued the existing velcro piece to the bottom and then secured it to the top with a small ziptie. As others have said, this protector is very comfortable once you've had it on. Your body heat warms it and increases its pliability. It is more comfortable, more protection, and better airflow than my old Knox protector. I will likely be buying another one of these for an Alpinestars jacket that did not come with a back protector. These things are great. No reason not to have one in your jacket. August 15, 2015
Great Upgrade Bought this in a M to replace the stock foam in my 2014 GP-R. It's slightly smaller than the stock foam, but obviously a lot more durable. You can't even feel this thing in your jacket once it conforms to your back. Great upgrade for little money and will give you more peace of mind when wearing your jacket knowing it has a legit back protector. August 14, 2015
Feels good I bought this to replace the foam insert in my T-GP R Air jacket. The difference is night and day. I can feel the insert contouring to my back when I ride. It has a good weight to it, I would still consider it light but it is enough weight to know it is there. It gives me a good feeling of protection. August 7, 2015
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