Fly Racing Prizm Knee Guard
(discontinued)

Vital Rating:
Discontinued
Related:
Where To Buy
Free shipping on orders over $50 (continental U.S. only).
International shipping available. Some exclusions apply.
Free shipping on orders over $50 (continental U.S. only).
International shipping available. Some exclusions apply.
TESTED: Fly Prizm Knee Guard
Rating:
Vital Review

Fly Racing Prizm Knee Guards are the lone mountain bike knee pad option from the long-established Moto and now MTB brand. The $84.95 knee protectors are well-built and offer some pretty high-tech protection solutions.

Like most modern pads, the Prizms fall into this in-between region of protection. They're not quite full-on DH pads, but they're a bit bulky for a lot of uphilling. Fly worked with a European foam developer to create their soft Reaktiv Prizm Foam (RPF) which is used as the main protective element in the pad. The pad's design, foam usage and outer Kevlar construction means the Prizm is a CE Level 1 (EN1621 / 2012) approved knee protection system. One key feature of the RPF is that heat makes the foam more pliable. The foam will become more supple as it warms up, so body temperature along with strategically placed cuts in the foam ensure a secure, form-fitting experience.

Fly Prizm Highlights

  • RPF = Reaktiv Prizm Foam. Fly Racing has developed their own CE-approved protection. It is a high density memory foam that has been sliced with a prismatic pattern to allow the pad to mould to the shape of the user. The foam is also body temperature sensitive meaning it becomes more supple when you put the pad on increasing comfort when pedaling
  • Kevlar front panels - heavy duty front panels with high abrasion resistance to increase durability of the pad.
  • Side knee protection
  • Moisture wicking, antibacterial lycra pad liner
  • 'Floating' neoprene patella cup with silicon printing to centralize the pad and prevent it from slipping down
  • Strategically placed elastic banding with silicon printing to help prevent the pad from slipping down
  • Open back design prevents material bunching up at the back of the knee when pedaling and increases breathability
  • Asymmetric design to have left and right specific for improved fit and function
  • Extensive use of flatlock stitching for increased strength, durability and comfort
  • Innovative lacing system around the upper calf. Positioned above the widest point of the calf this helps prevent the pads from slipping down in use.
  • MSRP: $84.95 USD

Initial Impressions

I used the pads riding Whistler and on some local XC (trail) rides. Out of the box, the pads felt stout and durable. The protective foam was pliable, but a bit stiff initially. The pads are marked left/right and they slid on easily enough. I wore size M/L. Fly also sent me size XL which was both too long and too big in diameter for my legs. For what it's worth, I typically wear a "Large" in other pads.

As expected, the silicone grip strips on the thigh area gripped my legs well and the Prizms flexed nicely when bending my knees. The strapless design was secure and the draw-string on the calf area was nice touch, and I was stoked with the lack of elastic and/or velcro straps flapping around. I didn't need to cinch it up much, but skinny-legged riders may appreciate the option. Though I experienced no problems, I wondered about the surplus string dangling for riders who may need excessive cinching in the calf area.

I have short legs, so the pads covered a good bit of my upper shin. I liked that. I think riders with more average legs will feel the pads offer ample lower knee coverage, but not upper shin coverage like I experienced.

On The Trail

Some dusty, hot runs at Whistler and the pads stayed planted and unnoticeable...which is exactly what they should be. I would pull the pads up my thigh before each run, but it was a minimal adjustment and nothing like pads I've had in the past that would slip down considerably. The snug calf zone is what kept the protection in the right place. The knee cup would not drop down, out of position, even if the thigh cuff had slid down a bit. During impact, having the cup in the right place is all that matters. I never hit the dirt at Whistler, but I felt the pads were dialed for the bike park, staying in place and offering a feeling of security. They were not a distraction to my riding which is also crucial. Post-ride, I was never in a major hurry to get them off, which speaks to their comfort.

Back at home, I took the pads on a couple XC rides. Weather was dry and temps were in the mid-80's. The pads are a bit bulky for long uphills. I've never been a fan of riding in pads during climbs, however. Riders who use packs, attacking a long uphill to a long downhill ride will probably store them on the uphill and put them on before the descent. When descending, they felt great, just like my experience at Whistler. I was on a hardtail, so I was getting rattled considerably more than normal, but the pads were secure. I managed an OTB on one of the tech sections of trail at home, and the top of my knee hit the deck pretty good, but the pad was in place and did its job. A soft pad is never going to prevent that smack to the dirt and rock like a hard, plastic guard, but I was surprised at how well they absorbed the impact. Without the Prizm in this crash, I would have been bruised, sore and probably bloody.

Things That Could be Improved

If the majority of your riding includes longer, sustained climbs and you choose to carry the pads in your pack on the way up, having to remove shoes to put the Prizms on before the descent could be a downer.

Long Term Durability

While I have only ridden with these pads a handful of days total, I don't see why long-term durability would be an issue. There is no fraying or stitching out of place. I've used pads in the past that have shown such wear after a ride or two. While I personally prefer not having elastic and velcro straps for security, the only question I may have is how long the elasticity of the thigh cuff would stay tight. Having said that, as mentioned above, the security in the calf region is what keeps this pad in place, the thigh cuff comes in a distant second concern when it comes to retention.

What's The Bottom Line?

If you're looking for well-rounded knee protection that leans toward aggressive riding on the regular, the Fly Prizm is up to the challenge.

Visit flyracing.com for more information.


About The Reviewer

Shawn Spomer has been mountain biking since 1998 and has been involved in mountain bike media since 2001. He has been with Vital MTB as Content Director since 2009. While he may be more keyboard jockey than talented rider these days, his experience on the bike gives him the insight to investigate how a product will relate to the majority of consumers.

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Specifications

Product
Fly Racing Prizm Knee Guard
Riding Type
Dirt Jump / Slopestyle
Downhill
Freeride / Bike Park
Trail
Pad Type
Soft Shell
Material
  • Reaktiv Prizm Foam (RPF) - high density memory foam
  • Kevlar front panels - heavy duty with high abrasion resistance to increase durability
  • Moisture wicking, antibacterial lycra pad liner
  • 'Floating' neoprene patella cup with silicone printing to centralize the pad and prevent it from slipping down
  • Strategically placed elastic banding with silicone printing to help prevent the pad from slipping down
  • Open back design - no material bunching up at the back of the knee when pedaling, increasing both comfort and breathability
  • Asymmetric design to have left and right specific for improved fit and function
  • Lacing system around the upper calf, positioned above the widest point helps prevent the pads from slipping down
  • Knee/Shin Coverage
    Knee/Shin Pads
    Size
    S, M/L, XL
    Color
    Black
    Miscellaneous
    CE Level 1 certified to EN1621 / 2012 for knee protection
    Price
    $84.95
    More Info

    Working with a European protective foam developer, the FLY Racing design team was able to produce heat activated foam that molds to the knee through body heat to make a perfect comfortable fit. RPF is high-density memory foam that has been sliced with a prismatic pattern to allow the pad to mold to the shape of the user. Once the foam conforms to the leg the guard stays put and is comfortable all day. RPF foam is also body temperature sensitive, which means the knee guard becomes suppler as you ride for increased comfort while pedaling.

    For more info, visit ​www.flyracing.com.

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    Where To Buy
    Free shipping on orders over $50 (continental U.S. only).
    International shipping available. Some exclusions apply.
    Free shipping on orders over $50 (continental U.S. only).
    International shipping available. Some exclusions apply.
    Knee/Shin Pads

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