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Alpinestars Nucleon KR-2I Back Insert - Black

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in Body Armour

CE approved Level 2 back insert for Alpinestars jackets and suits

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Was $41.09

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Customer Reviews for Alpinestars Nucleon KR-2I Back Insert - Black

Alpinestars Nucleon KR-2I Back Insert - Black
April 30, 2020

Lovely to wear!

A great bit of kit that you don't notice when wearing the jacket. Fits into the appropriate pocket in the jacket no trouble. Brilliant value as well.

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Alpinestars Nucleon KR-2I Back Insert - Black
April 15, 2020

Great product!

Product functions perfectly, very comfortable in jacket pouch and it moulds to your body very quickly and easily whilst riding! Definitely recommend!

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Alpinestars Nucleon KR-2I Back Insert - Black
March 30, 2020

Just what I needed

I needed a back protector for an Alpinestars jacket I bought last year - it's like a wind shell type jacket with a hood. The small fits perfectly into the jackets mesh holder, and moulds to your back so not uncomfortable, in fact hardly notice it's there. Amazing service as usual from SBS

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Alpinestars Nucleon KR-2I Back Insert - Black
March 22, 2020


Good value and an essential piece of protection for any Alpinestars jacket. Fits in the pocket and is almost unnoticed especially once worn for a short while

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Alpinestars Nucleon KR-2I Back Insert - Black
March 13, 2020

Great extra protection

Excellent quality back protector. The material softens up with bodyheat and is very comfortable. I added mine to an Alpinestars Hoodie for some extra protection.

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Alpinestars Nucleon KR-2I Back Insert - Black
March 9, 2020

Extra confidence than stock

I've moved from an RST jacket with an 'aero' hump that had a back protector in it which offered full back protection. Switching to an Astars jacket I also wanted the back protection to not feel exposed, however the back protector sits much higher up leaving a portion of the lower back exposed. I don't think it would be much of an issue in a crash however I do feel more exposed than on my old jacket. For full protection a dedicated back protector is needed.

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Alpinestars Nucleon KR-2I Back Insert - Black
February 28, 2020

Back protection without the hump.

Great bit of kit. Fits perfect in Alpine Stars. Protects your back, nuff said. Why you hesitating, just get it. Don't want to regret not getting it do you!

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Alpinestars Nucleon KR-2I Back Insert - Black
February 27, 2020

Light and Comfortable

Fits well in my Alpinestars V2 jacket and is barely noticeable. high quality from Alpinestars.

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Alpinestars Nucleon KR-2I Back Insert - Black
February 13, 2020

Great fitting protector

Strong bit of kit. Good fit for my Merlin jacket. Great deal and delivery from Sportsbikeshop

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Alpinestars Nucleon KR-2I Back Insert - Black
February 4, 2020

Really good

Really nice back protector,you don't even know it's there

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Alpinestars Nucleon KR-2I Back Insert - Black

OptionMaximum heightMaximum width

The latest in back protection inserts from Alpinestars is the Nucleon KR-2i soft back protector insert. Suitable for all Alpinestars jackets or suits that feature a back protector pocket. It's design conforms to the latest back protector standards with it's Level 2 CE-certification (EN1621-:2014). The 'Nucleon' back protector's design has been ergonomically profiled for an optimised fit, whilst the lightweight design and flexibility with incorporated airflow system helps to keep the wearer both cool and comfortable. This highly protective back protector is quick and convenient to insert and offers the perfect fit for the ultimate in safety performance.

Back protector compatibility chart

  • Level 2 CE approved
  • Lightweight, Flexible Design
  • PU Injected Impact Foam
  • Ergonomically Designed Profile
  • Perforated For Breathability & Comfort
  • Channel Ventilation System For Optimised Airflow


Alpinestars, a truly world class brand of motorcycle apparel. Founded in the early 1960s by Sante Mazzarolo, Alpinestars has grown to be a world leading manufacturer of professional racing products such as leather jackets, jeans, boots and 1 piece suits. Whilst their leathers are worn by some of the biggest names in bike racing, they also specialise in high performance textile jackets, jeans and gloves. From F1 to Karting, the World Rally Championship to NASCAR, Alpinestars work with the very best drivers and riders to bring design innovations to all aspects of professional motor-sport.

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Questions and Answers

Questions and Answers

  • What size do i need 2 fit 4x drystar jacket

    March 16, 2020

    You will require size Large.

  • I have just received an Alpinestar Ares goretex jacket 2xl what back proctor will fit this jacket? Many thanks.

    December 13, 2018

    A 2XL jacket requires the large Nucleon back protector.

  • Hi I have purchased an Alpinestar Jaws Leather Jacket off yourselves recently- size 42 chest. I'm 6ft 3" and slim. Jacket is snug but good fit. Which size would you recommend re. the back protector?

    September 6, 2018

    We would recommend the medium back protector.

  • Hi, looking at purchasing the Alpinestar GP plus R v2 size 46 U.K. Q1 is this the best back protector? Q2 what size for the 46?

    April 25, 2018

    This is the Level 2 CE approved back insert that Alpinestars recommend. If you were to purchase an Alpinestars Jacket in a UK size 46, you require the Large insert.

  • I have an Alpinestars Motegi Leather Jacket size EU56. Which size do I need as the compatibility chart isnt clear if they are using the Euro or product size?

    August 14, 2017

    You will need a size large for your jacket

  • I have an Atem one Piece suit 3 years old.It has no pocket for a back protector just the press stud fixings. How is the Nucleon held in place as there are no reciprocal stud fittings shown on the photos of the protector ?

    January 26, 2017

    This product is only suitable for all Alpinestars jackets or suits that feature a back protector pocket.

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