Free Shipping Over $39.99

Orders $39.99 or more ship free within the contiguous U.S.

Free Shipping Policy

No Restock Fees

Doesn't fit? Don't love it?

Return any unused item within 30 days for a full refund.

No-Hassle Returns

  1. Obtain an RA number
  2. Package your product
  3. Send it back to us!
Return Policy

Price Match Guarantee

Found it for less?

RevZilla will match any advertised price on new merchandise available through another authorized U.S. dealer.

Price Match Policy

Elite Service Rating

Our goal is to provide the best possible shopping experience to every enthusiast who visits RevZilla.

See what our customers are saying about us:

Customer Reviews

ZillaCash Rewards

The ZillaCash rewards program is very straightforward - if you have a RevZilla account, you may already be taking advantage of ZillaCash rewards. Review the following guidelines to see how easy it is to maximize your rewards and put your ZillaCash to work for you.

  • Earn and redeem ZillaCash credit automatically with each order - no fine print, no strings attached, and no hoops to jump through to cash in.
  • All you need is a RevZilla account to start earning - Simply log in each time you shop with RevZilla and we’ll take care of the rest, keeping more money in your pocket just for shopping with us.
  • Earn $5 for Each $100 You Spend on eligible products - up to a maximum of $30 ZillaCash per order for orders totaling $600 or more. Any ZillaCash you earn is automatically applied to the next purchase, so you can sit back, enjoy the ride and feel the savings blow through your hair.
Learn More About ZillaCash

Alpinestars Nucleon KR-2i Back Protector Insert

Item: P279619

The Alpinestars Nucleon KR-2i brings CE Level 2 protection and airflow to both men's and women's Alpinestars jackets. Read More

$59.95
Learn More

Product Details

Alpinestars Nucleon KR-2i Back Protector Insert

The Alpinestars Nucleon KR-2i Back Protector Insert fits all Alpinestars jackets and race suits and delivers CE Level 2 impact protection.

Features:

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

Shipping

Orders $39.99 and over qualify for our fast free shipping offer. Click Here for FREE Shipping Terms and Conditions.

Please see our International Orders page for orders shipping outside the US.

We show real-time availability on this product page when you select the size/color item you want.  Most items will ship the same business day an order is placed,however if an item requires additional processing time a message will be shown indicating such.

See our full Shipping Policy for further details.

Returns

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.

Product Description
The Alpinestars Nucleon KR-2i brings CE Level 2 protection and airflow to both men's and women's Alpinestars jackets. Read More
Part Numbers
Tap To View Part Numbers
Shipping & Returns
Tap To View Shipping & Returns Details

Reviews & Questions

4.8 / 5.0
102 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
86
10
6
0
0
Bang For The Buck
4.7 / 5
Protection & Durability
4.8 / 5
Features
4.5 / 5
Comfort
4.6 / 5
Style
4.6 / 5
Air Flow
4.6 / 5
Fit
Small
True
Large
Bang For The Buck
5 / 5
Protection & Durability
5 / 5
Features
5 / 5
Comfort
5 / 5
Style
5 / 5
Air Flow
5 / 5
save my life
Bought this product two months ago. I recently had a motorcycle accident going like 60mph in the canyons, it observer all the impact of me hitting the floor and save my back from breaking, I believed it save my life. I will surely buy this product again.
January 21, 2015
Ride:
2014 Yamaha YZF-R6
Bang For The Buck
5 / 5
Protection & Durability
5 / 5
Features
5 / 5
Comfort
5 / 5
Style
5 / 5
Air Flow
5 / 5
did the unthinkable and used it on a non alpinestars jacket!!
I wanted a higher level of back protection for my icon jacket i use for commuting to work and around town. I found this alpinestars nucleon and saw the review on youtube. Needless to say seeds were planted and i recieved it for Christmas! !! Thanks santacycleclaws!!. My family member ordered a size medium off the alpinestars chart and and upon putting it in my icon jacket it was about 2 inches short. Luckily my girlfriend is a master seamstress (thats a joke but shes good) she hemmed up the lower portion of the back protector pocket so that the back protector is in the correct place as illustrated on the back of the nucleon package and took out the extra slack. All is well. It forms to the body and is relatively light weight. It breaths well and does appear to have a good amount of protection. I cant speak for an actual crash but i did have my girlfriend kick me a couple times in the back and it felt like a gentle massage. Great product and thanks again revzilla . If you are going to put this in any icon or similar jacket i would recomend getting the large version although the medium worked ok with small alterations. by my measurement the large nucleon will be about 1 inch shy being 18 in in length by 10.5 in wide . The icon stryker style foam pad was 19 in in length and 10.5 in wide just for reference if anyone is thinking about doing this. The medium nucleon is 17 in long by 10 in wide . Some may think it's taboo to mix and match brands like this however i like my jacket and i like what alpinestars is doing here so i went with it im sure i wont be the only one who will be doin this.
December 27, 2014
Ride:
2005 Yamaha YZF-R1
Bang For The Buck
5 / 5
Protection & Durability
5 / 5
Features
3 / 5
Comfort
5 / 5
Style
5 / 5
Air Flow
4 / 5
Unfortunately Tested, Stellar Results
A week after receiving this back protector as a gift I high-sided and landed on my rear and back. The back protector did a stellar job of protecting me. My back suffered no injuries while my rear was a bit bruised and my pride even more. After trying on many back protectors, this one was the slimmest by far, necessary since I often commute with a backpack on. Obviously the thickness and ability of it to protect me were not an issue in my situation. It has good breathability but as with any protector you will trap some warmth on your back. The material is very interesting as you can bend it and it is flexible. During impact, it is firm and unyeilding. It fit perfectly inside my Alpinestars T GP-Plus R Air Jacket.
March 17, 2015
Ride:
2007 Honda CBR600RR
Bang For The Buck
5 / 5
Protection & Durability
5 / 5
Features
5 / 5
Comfort
5 / 5
Style
5 / 5
Air Flow
5 / 5
Its your back!
Who doesn't want to protect your back? Fixing up bikes can be fun, but don't neglect yourself. You deserve to walk away.
March 3, 2015
Ride:
2014 Yamaha YZF-R6
Bang For The Buck
4 / 5
Protection & Durability
5 / 5
Features
4 / 5
Comfort
5 / 5
Style
5 / 5
Fit
Small
True
Large
Air Flow
5 / 5
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
Bang For The Buck
5 / 5
Protection & Durability
5 / 5
Features
5 / 5
Comfort
5 / 5
Style
5 / 5
Air Flow
5 / 5
A cheaper back protector with a great protection rating
This wa one of the cheaper back protectors that has a good protection rating. Covers up more of my back than I would have thought which is a plus.
July 22, 2015
Ride:
2005 Kawasaki Ninja 500R
Bang For The Buck
5 / 5
Features
5 / 5
Comfort
5 / 5
Style
5 / 5
Air Flow
5 / 5
Awesome bang for buck item
Put this into my Alpinestars textile jacket (2013 model I believe) and it fit just perfectly. It replaced the soft/filmsy foam that was there and to be honest I can barely tell this back protector is there. It flexes and contours so nicely yet it definetely resists impact (had folks kick/punch and ran it into doorways).
March 9, 2015
Ride:
2012 Triumph Daytona 675
Bang For The Buck
5 / 5
Protection & Durability
5 / 5
Features
5 / 5
Comfort
5 / 5
Style
5 / 5
Air Flow
5 / 5
Not fully tested (thank god)
I have not gotten into any accidents so this review will only cover fit and comfort. Inserted into my gp plus and then my sp1 jacket, i can not feel the protector while riding. I basically forget its there. The jacket is perf'd so air goes thru well. one thing i did notice is that when i bend it, it stays in that shape, so while your back is bending, this conforms to your shape.

no issues with this product.

can not testify as to its protection sorry
November 4, 2014
Ride:
2007 Honda CBR600RR
Bang For The Buck
4 / 5
Protection & Durability
5 / 5
Features
5 / 5
Comfort
3 / 5
Style
5 / 5
Air Flow
5 / 5
Feels very safe, but rigid
I'm happy with this back pad - it fits nicely in my Alpinestars Stella jacket, the only drawback is how stiff the pad is. It doesn't really conform to my body at all. Overall it makes me feel safe though and I'm glad to have purchased it.
May 4, 2015
Ride:
2006 Suzuki GS500
Bang For The Buck
5 / 5
Protection & Durability
5 / 5
Features
5 / 5
Comfort
5 / 5
Style
5 / 5
Air Flow
5 / 5
Wow! Simpler design, more protection, and less expensive than previous models? Yes Please!
I have a bionic air insert in a leather jacket that I was planning to use in a new Adventure style jacket I purchased recently. However, the bionic air insert was too large. So, I shopped around for what was new on the market and found this. It turns out it's the same CE2 armor that's used in my Adventure jacket for the shoulder and elbow armor. It's extremely lightweight and conforms to your body so it's very comfortable and it breathes great too. I can't comment on how well it does to protect my back, and I hope I never have to find out, but it does seem to absorb impact very well with the few silly tests I tried with it. You can't go wrong with buying this to replace the foam that comes with most jackets. At this price, it's a no-brainer.
May 11, 2015
Ride:
2015 BMW F700GS
102 Customer Reviews
102 5/5
Read All Reviews
35 Questions & 59 Answers
Ask A Question