Ion's K-Pact knee pads have been on the market for several years, but they recently underwent a slight revision in order to improve their breathability. The basic design remains the same, though, with a SAS-TEC viscoelastic pad that sits over the kneecap area, and two foam pads on each side of the knee for additional protection.
Velcro straps at the top and bottom of the pads are used to adjust the fit, and there's also a strip of silicone inside to help keep them from sliding down. The material around the back of the leg is what was changed for 2018 – Ion now use what they call “Super Perforator Neoprene.”
Ion K-Pact Details
• SAS-TEC viscoelastic main pad
• Closed cell foam side padding
• EN1621-1 certified
• Sizes: S, M, L, XL
• Colors: black / blue / Whipeout
• Weight: 462 grams (size medium)
• MSRP: $89.95 USD
In other words, it's neoprene with a bunch of holes in it to allow for better air flow while still providing some protection against abrasion in the event of a crash. Along with the Swiss-cheesed neoprene, a mesh panel at the back of the knee provides additional ventilation.
The K-Pact knee pads are available in black, blue, and printed pattern called Whipeout, in sizes S – XL. MSRP: $89.95 USD. Performance
The K-Pact knee pads run a little bit small, and if you're typically in between sizes you'll likely need to size up. Ion has roots in the kitesurfing world, and pulling the K-Pact pads on has a similar feel to donning a wetsuit. They're very snug at first, but after a few minutes they're not noticeable at all. That being said, if you're the type of rider that likes to slide your knee pads down while climbing, and then pull them up for the descent, these aren't the best option due to how snugly they fit; once they're in place they don't want to go anywhere.
The K-Pacts are a little bulkier than some of the more svelte trail-oriented options on the market, but that extra padding sure is nice to have when you smack the inside of your knee against the top tube, or find yourself taking an unplanned trip off the trail and into the woods. The overall comfort is excellent as well, and I didn't experience any irritating chafing or rubbing even after wearing them for seven hours straight while riding myself stupid in the bike park.
As far as breathability goes, I haven't had the chance to subject them to truly sweltering temperatures, but on warmer spring days they haven't given me any reason to complain. I've managed to avoid any massive encounters with the ground (knock on wood) while wearing these pads, but I have put in plenty of long rides where they were banged against bike frames and covered in mud, and despite all of that the stitching and seams are still holding strong,Pinkbike's Take