Bluegrass Seamless Lite D3O Back Protector review – excellent, unobtrusive rear protection

This lightweight protection vest from Bluegrass uses a fast-drying mesh material to support an impact-hardening back panel

Bluegrass Seamless Lite D3O Back Protector
(Image: © Mick Kirkman)

Bike Perfect Verdict

As one of the most cool, comfortable and body-hugging vests on the market, Bluegrass’ seamless vest is a top choice for wearing on every ride or racing enduro in hotter temperatures. The lightweight stretchy Dryarn material used also has excellent wicking capabilities.


  • +

    Super comfortable against skin

  • +

    Superbly breathable and moisture-wicking

  • +

    Chafe-free and well cut

  • +

    Back protection panel covers broad area

  • +

    Never flinches or rides up


  • -

    Not the cheapest

  • -

    D3O can be stiff when putting on if cold

Why trust BikePerfect Our cycling experts have decades of testing experience. We\'ll always share our unbiased opinions on bikes and gear. Find out more about how we test.

Like all the best MTB body armor, Bluegrass’ D3O back panel vest aims to fit like a second skin so riders are more inclined to wear protection on a higher percentage of rides. To achieve this, it uses a close-fitting, highly breathable, Dryarn material with cutaway panel using an even more open weave mesh (more like a string vest) in the pectoral and tummy zone.

Bluegrass Seamless Lite D3O

The panel is extremely light and has a superb body-tracing fit  (Image credit: Mick Kirkman)

Design and specifications

The Seamless Lite is long in the body so it resists riding up while riding dynamically and can also be tucked into shorts or riding trousers for extra stability. 

The main material uses a microfibre fabric which is soft next to the skin and the ‘Seamless’ part refers to how the vest is a pullover design, rather than using any potentially bulky or heavier zips to secure it.

Extremely-stretchy, this Dryarn material used is an Italian-made fabric that’s lighter than traditional materials and delivers a gentle elasticated compression fit. It traces and sticks to the body exceptionally well and the panels mentioned with a coarser mesh (more like a road cycling ‘string vest’) around the abs and under the collarbone, dump heat and moisture faster than any rival products I’ve tested.

The wide back panel has broad coverage right across the middle and below the shoulder blades (not just the spine), and also reaches right down the tail bone, and the overall fit is low profile and extremely unobtrusive. 

The vest also carries a useful stash pocket at the foot of the rear armor that can carry a few snacks or small tools.

Bluegrass Seamless Lite D3O

The vest has a useful stash pocket at the foot of the rear  (Image credit: Mick Kirkman)


The impact-hardening D3O polymer Bluegrass’ panel is made from has a shape that mirrors the body’s natural curves well, but can be a bit stiff once first put on in cold weather. It soon heats up and conforms to your body shape though and once fluid it sits on the body almost invisibly. There’s an extremely light, near invisible feel when riding and a superb body-tracing fit, which makes the Bluegrass Seamless Lite D30 vest stand out in a sea of similar products. 

Protection coverage is good with the well-ventilated D3O panel extending right across the width of the back to protect organs and upper ribs on the backside. This panel also lets air in nicely thanks to an open webbing design that breathes next to skin.

Most other vests with this much back coverage tend to get a bit flappy or peel away from the spine, but the flexible D3O armor here stays tight on the body and twists and conforms well to any movements. Overall, cooling is excellent and the wide spaces in the mesh fabric feed loads of fresh air onto the front body to regulate temperature and also help dry the vest quickly on sweaty days.

Even though the body material is very elastic and stretchy so it never gets uncomfortable, it balances the give with enough hold and stability to stay firmly in place and also retain its original shape after lots of use and washing.

Bluegrass Seamless Lite D30

There's no protection to the front of the vest (Image credit: Mick Kirkman)


Bluegrass’s Seamless Lite D3O vest is expensive, but the high price delivers a product so comfortable you’re inclined to wear it more often, rather than swerving it for reasons of comfort or temperature control.

The stretchy-yet-tight fit works great and being seamless also means no annoying lumps or creases in the construction. Being very light means no excess weight to carry around either, ensuring this vest feels more slimline and less bulky than rivals under riding kit. 

Bluegrass’ best asset though is the exceptionally good cooling and temperature management from the soft and snug Dryarn material that keeps the back panel super stable without ever feeling too tight against skin.

Bluegrass Seamless Lite D3O

The Dryarn material offers excellent breathability and moisture-wicking properties (Image credit: Mick Kirkman)

Tech specs: Bluegrass Seamless Lite D3O Back Protector

  • Price: $250 / £170 / €200
  • Weight: 474g (large)
  • Sizes: S/M, L/XL
  • Colors: Gray
  • Rival products: Dainese Trail Skins Air Vest, IXS Flow Protection vest
Mick Kirkman
Freelance writer

An ex-elite downhill racer, Mick's been mucking about and occasionally racing mountain bikes for over twenty years. Racing led to photo modelling and testing kit for magazines back in the day, and, nowadays, he's mostly riding enduro-style terrain on conventional and electric bikes. As curious as ever about products and tech, he's as likely to be on the other side of the lens or computer screen rating, reviewing and shooting all the latest gear. Mick's list of regular clients includes Bike Perfect, MBR, MBUK, and most of the leading UK MTB publications at one point or another.