Versus: Zippered Knee Pads

Zippers are magic. Their witchcraft is totally beyond me. I once listened to an hour-long podcast about zippers, and I still can’t explain exactly how they work. Maybe that’s why it wasn’t until just a couple years ago that zippers started showing up on knee pads. Maybe we felt about zippered pads the same way we used to feel about hydraulic brakes or electronic shifting. “What happens if one of those things fails on you out in the field?” Well, you won’t have a knee pad. No big deal. And anyway, after seven months of testing these five knee pads, the only failure I experienced was an occasional need for zipper lube (it’s a thing) and one torn velcro strap. 

Velcro straps, since I brought it up, are not magic. They’re simple tools, well suited for simple objects. Like luggage or children’s shoes. They’re not great for strapping protective equipment to a highly mobile joint. That’s one reason why slide-on, fully enclosed pads are so nice. They spread their tension evenly across the whole joint. They don’t dig in or cause pressure points. More robust, full-sized slide-on pads still tend to need Velcro straps, but only for adjustment and some supplementary stability. They are more comfortable and stay put better than pads that rely on straps alone. But every time you slide them on, you have to take your shoes off, like you’re going through airport security but with slightly more dirt on the ground. 

Zippered knee pads, if done right, combine the best of both worlds. They offer an even tension across the joint that a strap just can’t, but they open all the way when you need to put them on or take them off. This feature is not important for everyone. If your rides are primarily on undulating technical singletrack, you may not be taking your pads off at the bottom of every hill. Or if you only wear pads at the bike park, you’re likely not doing enough pedaling to bother with ever removing them. But if your rides switch between long climbs and long descents, you might as well get comfortable. So, I gathered five zippered knee pads in an effort to unlock their mysteries. Here’s what I found out.

Ion K-Pact Zip Knee – $109,

Safe, stable, but sweaty.

Every brand has a different opinion on what should happen behind your knee, and the Ion K-Pact Zip takes an interesting approach. Instead of swapping to thin, nylon-like material in the interest of breathability, the K-Pact Zip uses a thick but heavily perforated neoprene throughout the entire pad with one exception at the very pit of the knee. This approach does several things. It adds a little extra protection where there would otherwise be little or none. It also provides more consistent tension instead of mixing various levels of stretch. And it adds durability. Where the Scott Grenade Evo Zip was starting to show some wear behind the calf, K-Pact Zip could handle a lot more trauma. It’s not the most breathable of the bunch, but that wasn’t its primary focus. 

The main pad over the knee cap was the most three-dimensional of the bunch. It centered itself automatically, and it stayed there. Which is fortunate, because the Velcro straps at the top and bottom of the pad were maybe a little too elastic to make much of a difference. And because those light-action straps wrap around forward from the outboard side of the knee, it’s important to pull them all the way across so they don’t catch passing brush and get snatched out of place, which happened to me occasionally until I learned to pay more attention to stretching those straps inward.

K-Pact Zip offers the higher, EN 1621-1, Level-2 protection, but as far as how robust they feel, they land somewhere in the middle of the pack. More full-coverage than the G-Forms and the IXS, but a little less than the Leatt and Scott. They were equally mid-pack in pedaling comfort, edged out by the Leatt and the minimalist IXS Flow Zip. The self-centering pads and the stout but flexible material surrounding them kept them in an optimal position, though they fell just short of that second-skin feel.

The only pads easier to take on and off were the Scott Grenades, and only because those pads  have only a thin strip of material to keep the zipper off your skin while G-Form, Leatt and Ion have a thicker, more substantial flap, the Ion having the most substantial. These pads truly makes the inside surface of the zipper disappear, which is worth a few extra seconds.

 

Scott Grenade Evo Zip – $100

Full coverage, easy access

The Grenade Evo Zips feel nice and substantial on the knee and in the hand. The smaller pads surrounding the main pad are tightly connected, but still manage to flex in a way that keeps them from fighting the natural motion of straightening and bending your leg. It feels like it truly offers full coverage, especially above the main pad, where a stem or handlebar can easily find a way through sparse padding. And the two side pads that wrap around the top of the tibia are actually enveloped in the same Kevlar-like material that covers the main pad. Although that main pad is not as concave as the Ion, the assembly of the Grenade’s overall structure does much of the work in keeping everything in place.

Evidenced by the slightly lower rating of EN1621-1 level 1, the primary pad covering the kneecap doesn’t feel particularly stiff or thick. But regardless, the Grenades made me feel more secure than any other pad in the test. It felt like there was no direction an impact could come from that I wouldn’t be ready for. It also helped that Scott uses brand-name D30 material as its primary protection. The malleable but extensive coverage made me feel like my knees were wrapped in a sort of forcefield, though that does mean that they were the second warmest pad in the mix just behind the Ions. But at least they were comfortable, and they do take steps to let as much heat out as possible.

Unlike the Ion, the material that makes up the Grenade’s overall structure changes sharply across the back, where, just below the band that wraps around the thigh, it turns into a wide panel of thin mesh. I was able to feel sweat evaporating back there, but the  large panel of thin, flexy material had me relying on the lower strap to keep it feeling secure. You may notice, though, that one of those lower straps is missing. It tore off about two months into using these. I know exactly where it happened, and it probably would have torn the strap off any of these pads.

Next to the less substantial IXS Flow Zips, the Grenades were the easiest pads to take on and off. The stretchy venting material across the back meant less fighting to get the zipper to line up once I’d started it. For anyone who needs a substantial pad and pictures themselves taking them on and off frequently, the Scots are the best option.

 

Leatt 3DF 5.0 Zip Knee – $100

For all-day shredding

On the other end of the ease-of-installation scale are the 3DF 5.0 Zip Knees from Leatt. I had a harder time putting them on because of one simple reason. The zipper starts at the bottom and goes to the top, not the other way around like Ion, Leatt, Scott and IXS. Doesn’t seem like it’d be a big deal, but I’ve found that the easiest way to put on a zippered pad is to do the zipping with the pad starting down around your ankle where there’s plenty of slack. Zip it up gently, and then slide it up into place. That way, you’re not pressing against your skin, fighting the increasing tension as you move the zipper upward. It doesn’t seem like much but, even down at the ankle, zipping up from the bottom up doesn’t leave a lot of breathing room for connecting the zipper, situating the protective flap behind it and making it to the top.

That said, this is literally the only flaw I found in the Leatt pads. While pedaling, they are the least distracting of all of the pads I tested other than the lightweight IXS Flow Zip. Leatt paid a lot of attention to how knee pads need to move. There was no significant wrinkling or bowing out, and no shifting as I stood up and sat down. And they’re designed to work with only one strap. The not-too-stretchy back panel meant the structure of the pad itself was able to do the work to keep it in place, while the upper strap was just there for a little extra tension if you needed it. And that upper strap does an elegant job of disappearing once it’s attached. It slides out of a reinforced port and stretches backwards to the rear of the pad. I never felt it back there, and, more importantly, it never caught on anything. 

These are the pads I was most likely to leave on my knees all day if the climbs were relatively short and the trails relatively gnarly. The DBX 5.0 Zips meet the slightly lower protection bar of EN1621-1 Level 1, but they feel like the perfect bike park pad. Slide them down to your ankles if you’re in a long line at the gondola, or zip them off if you’re in a longer line at Whistler’s Longhorn Saloon. 

 

G-Form E-Line – $110

Hard on the outside, cool on the inside

Now, we’re getting to the outliers, starting with the E-Line, G-Form’s first truly aggressive knee pad. Hard outer shell, Kevlar blend surrounding it, plus Velcro straps and a zipper. But nothing like the zippers in the rest of the bunch. Because G-Form wanted an open-back design, they limited the zipper to down on the calf end, and left the thigh end to be handled by a truly monstrous Velcro strap. You end up with something that does a far better job at both comfort and stability than most strap-only pads, but doesn’t offer the second-skin feeling that you can get with a good zippered pad. 

But they keep you cool. Not only is the heat that normally collects back there unable to collect in the first place, the open construction allows air to better reach the sides of the pad as well. And that’s actually part of what I didn’t like about the E-Lines. Instead of hugging my knee, the pad would wing out at the joint as I bent my leg. If I hadn’t grouped the E-Lines next to four full-zip pads that don’t do that, it wouldn’t stand out quite as much. But swapping regularly between these other options spoiled me a bit. To be fair, as the E-Line’s structure deforms while pedaling, the functional protective bits are still right where they belong, ready to take an impact. But if you let things like that get in your head while riding, these pads will get in your head. They lack the secure feeling that the rest of these pads offer. That feeling that your knees are fully enclosed. If you’re reading this because you’re after an easy-to-remove version of the full-coverage experience you get from slide-on pads, the E-Lines don’t offer it. But that doesn’t mean they don’t offer something valuable.

Without full-coverage construction, not only is there better ventilation, there’s less friction. It’s no surprise that the E-Lines trap and generate the least heat out of all of these pads, even the IXS Flow Zip. They’re also the only ones with a hard shell, a feature I wish were more common in general. Like all but one pad tested here, the E-Line pads offer EN1621-1 Level 1 protection, but that only measures direct force. The hard shell will allow these pads to deflect impacts better than softshell pads. And they have the advantage of their Velcro straps actually making a significant difference in fit, while the straps in the rest of the lineup only add a gentile bit of pressure. If you find pads getting a little shifty above the knee, the wide strap and generous traction pads on the E-Lines address that. But if you’re looking for a form-fitting, full-coverage pad and aren’t worried about ventilation, they don’t address it.

 

IXS Flow Zip – $115

Bikepackers, take note

These take an interesting approach to the zippered pad. Think of minimalist, knee-sock sort of structures like what we’ve seen from 7iDP or recent offerings from Pearl Izumi. But give them a deeper three-dimensional pad, a strap to fine-tune the tension and, of course, a zipper. That’s the IXS Flow Zip. At first, this approach didn’t make sense to me. The whole point of an easily removable pad is that you can, well, easily remove it. It’s ok to get something burly and overbuilt because you can just zip it off at the bottom of the trail. On the other hand, if you don’t need or want something burly and overbuilt, you can probably get something that’s cool, light, thin and flexible enough to just leave on for the whole ride. The Flow Zip is neither, but I think there’s something brilliant about it.

If it wasn’t clear already, these are beyond comparison to the above four pads. Those are more substantial and more protective than what IXS has done here. Although they do manage to offer EN1621-1 Level 1 protection, without any pads surrounding the main pad, they have somewhat limited coverage. But I immediately imagined a use for them. I’ve never used a pad better suited for lightweight, all-day (or multi-day) adventures. The kind of adventures where you’ll choose shrink-wrapped beef jerky instead of bagged beef jerky because it packs better. When those sorts of choices extend to protectives, they’re often the first to get cut. “I’m not out here to get gnarly, I just want to pedal.” Those are dangerous words. Makes me want to knock on wood just writing them. We let our guard down on those sorts of rides, and the Flow Zips are the perfect companion on a big day when you don’t want to overpack, don’t want to stop long to pad up, but don’t want to push your luck on the descents. They aren’t quite as refined as the thigh-high knee socks I mentioned above, but they are lighter and more flexible than anything else I’ve covered here. 

If I have any complaints on the Flow Zips is that they over-tech it a little with their straps. There’s one that appears to be there to keep the zipper from working its way loose, which I can’t imagine happening, and another to adjust tension, which the light, elastic construction makes somewhat unnecessary. Neither strap makes them any less comfortable, but they’re overkill.

On one of my go-to epic rides with a nine-mile undulating technical climb, I zipped on the Flow Zips at the bottom and eventually forgot they were there until I got to the four-mile fire road at the top and zipped them off until I got to the downhill. Normally, I’d have risked the first leg of that ride with nothing on my legs. But the Flow Zips split the difference between a bare-bones knee sock that just takes the edge off, and more robust pads that are too much for some rides. They’re a must-have in any survival kit.

Photos: Chris Wellhausen