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Alpinestars Nucleon KR-2I Back Insert - Black

Best Seller
in Body Armour

CE approved Level 2 back insert for Alpinestars jackets and suits

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

Alpinestars Nucleon KR-2I Back Insert - Black
August 29, 2019

Great protection

Perfect fit for my alpinestar jacket. Lightweight and very flexible

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Alpinestars Nucleon KR-2I Back Insert - Black
August 14, 2019

Good safety enhancement to jacket

Good level 2 back insert specific to Alpinestars jacket. It was for my wife's jacket which they don't supply with a back insert, but the pocket is there. Tried one from an old jacket but didn't fit. Glad the sportsbikeshop website gives details of which size you need depending on jacket size. Quality product, Wife says it is very comfy.

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Alpinestars Nucleon KR-2I Back Insert - Black
August 12, 2019

Love it

I don't even notice it's there. Super light and flexible yet nice and thick. Worth the bit of extra money and a perfect fit for my A-star jacket too. Medium pad in a Euro 52/US 42 jacket

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Alpinestars Nucleon KR-2I Back Insert - Black
August 6, 2019

Awesome bit of kit

Service from SBS is awesome great service and speed, this item turned up and it looks big and heavy but is not the case at all. I got this to go into my Alpinestars Valparaiso 2 Drystar Textile Jacket it fitted right in. The first ride was in 26C temp and my old back cover made me hot and have a wetback. This nothing with the front vents open on the jacket I can feel the wind go in and out thru the back protector. I now feel safe if the worse should happen as this item means business in saving me pain and some discomfort if the worse happens 5 star item

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Alpinestars Nucleon KR-2I Back Insert - Black
August 1, 2019

Confidence when riding

Recently bought a GP Plus R V2 jacket and I am a 46 chest, so the large size fits perfect and that's what you will need. It feels great and makes me feel I have given myself a stronger chance to limit injury if the worse happens. Given the price of these jackets I would expect them to be included in the price. Great service from SBS again

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Alpinestars Nucleon KR-2I Back Insert - Black
July 15, 2019

Certainly looks / feels the part

M fits my M textile jacket nicely and certainly looks / feels like it will do the job. Why doesn't this come with a jacket as standard I wonder / would pay the extra up front for it.

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Alpinestars Nucleon KR-2I Back Insert - Black
July 15, 2019

Spot on

This back protector is a perfect fit my my alpinestars jacket and is lightweight and comfortable.

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Alpinestars Nucleon KR-2I Back Insert - Black
July 12, 2019

Excellent service as usual

The way in which the sales system is set up at Sportsbike shop, the attitude of staff, the range of products, stockholding, delivery and communication is second to none! And no, I don't work for them. Once again, thank you.

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Alpinestars Nucleon KR-2I Back Insert - Black
June 24, 2019

Solid fit in the jacket

Feels robust and comfortable. Fits nicely into the jacket with no loss of comfort. Top buy.

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Alpinestars Nucleon KR-2I Back Insert - Black
June 11, 2019

Comfortable and Sturdy

Fitted it into an Alpinestars T-Missile Drystar jacket. Comfortable and feels very secure. Great bit of kit. Highly recommend.

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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

  • 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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