If you ride off-road, your knees are constantly challenged and at risk. I went for years with simple knee guards that offered only impact protection. I eventually paid for it with a torn ACL. While a proper knee brace won’t prevent all knee injuries, proper protective gear can make a huge difference. The new Alpinestars RK-7 Plasma knee braces provide EN 1621-1:2012 Level 1 knee protection, the same rating bestowed on Alpinestars’ excellent Bionic-10 Carbon knee braces. However, the RK-7 braces cost 47 percent less than the Bionic-10 braces, so you can protect your knees for $475 a pair.
Alpinestars’ explanation of what the RK-7 Plasma does is simple: “This brace provides optimal structural integrity, rigidity and comfort, and thus reduces the risk of sustaining injuries to the medial and lateral collateral ligament, the anterior and posterior cruciate ligament, and the lateral and medial meniscus.” The CE-approval backs this up. We can’t independently verify the claims, of course, but the certification is good enough for us. So, it’s all about wearing the brace while riding.
The RK-7 requires a little setup before putting it on for the first time. You have to decide how much movement of your knee it will allow. The braces’ ranges can be independently set from zero degrees of extension, which still prevents hyperextension, to a limit of 30 degrees short of hyperextension. Small plastic extension stops are inserted into two slots on each brace to set the range in five-degree increments.
Putting the extension stops in for the first time was a bit challenging for me, as I’m not particularly mechanically minded. For those who can assemble a transmission blindfolded, it will be a cakewalk. After you do it a couple of times to determine your preferred range of motion, it becomes easier.
The RK-7 braces also come with a set of hook-and-loop pads to fine-tune the fit at your knees. The pads will come in useful for those with slim knees.
I set up the four attachment points on the inside of each brace and never touch them again. Strapping the brace on is done solely with the four outer straps.
Putting the Alpinestars RK-7 braces on is easy. To start, they’re labeled “Left” and “Right”, which is a friendly reminder for the asymmetrical design. There are four straps with hook-and-loop closures that let you wear the braces as tight or as loose as you like. You’ll want the tightest feel that won’t cut off circulation, as you do not want brace rotation in a fall.
I tested the RK-7 with the extension stops that limit movement at 30 degrees short of hyperextension, as I have already torn one ACL. The 30-degree setting does interfere with walking, while the 0-degree inserts do not. During riding, I do occasionally run into the extension stops when standing, though I find that reassuring. It’s all a matter of how much protection you want to trade for increased movement.
With one small, easily remedied exception, the Alpinestars RK-7 knee braces are impressively comfortable. The soft material of the straps means you won’t notice the braces when you ride. However, the hook side of the strap tails irritated my skin. I solved that problem with Alpinestars Knee Brace Socks ($55/pair). If you prefer a two-piece solution so you can continue to wear your favorite socks, the Alpinestars Rk-S Knee Brace Sleeves ($35/pair) are for you. An advantage of the sleeves is that they fold over the top of the braces to help prevent the braces from moving while riding.
Six of the eight strapping points on the Alpinestars RK-7 knee braces are floating. In conjunction with the four-point hinge, my knee movement is natural and unhindered. The braces have a supportive feel, like good boots, which encourage me to ride harder because I know I have excellent protection. Speaking of the floating buckles, keep an eye on the top and bottom removable keyhole-mounted buckles, as they can escape when they’re in your bag—it has happened to me twice.
Putting this review together, I managed to test both the impact and hyperextension protections. I had an awkward low-speed dismount and inarguably felt the RK-7 Plasma brace hit the extension stops. I can’t tell you how glad I was to have the braces on.
A medium-speed over-the-bars excursion on a rocky downhill tested the impact protection of the Alpinestars RK-7 Plasma braces. The impact protection is Alpinestars’ new bio-based Plasma material. A recurring three-dimensional M-shaped pattern absorbs the impacts while maintaining the integrity of the armor. The armor is covered with a soft material for absolute comfort. Despite my brutal hit in the rocks, the patella shield took the full impact and left zero bruising. My knees were unscathed, and the braces were not displaced or damaged—I’m sold.
Also, when you buy riding pants, make sure they have room for knee braces. Some lower-priced pants lack the stretch needed to accommodate knee braces. I tested them with Alpinestars Racer pants and Answer Racing Akron pants and experienced no issues when putting the pants on or when riding.
The Alpinestars RK-7 Plasma knee braces strike a practical balance for riders seeking serious knee protection without the premium price. At $475 per pair, they deliver CE-certified protection against ligament, meniscus, and patellar injuries, with adjustable extension stops and bio-based Plasma impact armor. Setup takes patience, especially when inserting the stops. However, once dialed in, they fit securely and move naturally. Real-world crashes proved their worth, resulting in no knee damage or brace shift. If you’re done gambling with your knee health, the Alpinestars RK-7 braces offer proven defense that justifies the investment.
Photography by Kelly Callan
Alpinestars RK-7 Plasma Knee Braces Fast Facts
- Sizes: S – XL
- CE certification: EN 1621-1:2012 Level 1
- Color: Black/Red
Alpinestars RK-7 Plasma Knee Braces price: $475/pair MSRP
