Leatt 3DF Airflex Knee and Elbow Guards
Size Tested: S/M
Elbow Guard:
MSRP: $79
Stated Weight: 100 grams each
Features:
- Super slim 6mm CE impact certified
- Armourgel ultra slim impact absorbing gel
- MoistureCool wicking fabric
- CE certified for impact protection EN1621-1
Knee Guard:
MSRP: $99
Stated Weight: 105 grams each
Features:
- Super slim 6mm CE impact certified
- Armourgel ultra slim impact absorbing gel
- MoistureCool wicking fabric
- CE certified for impact protection EN1621-1
Locations Tested: Park City, UT; Moab, UT
Days Tested: 15
Even though mountain biking has a tendency to produce cut-up knees and elbows at a phenomenal rate, many mountain bikers don’t wear body armor. While it makes a ton of sense in theory (costing less than stitches and helping prevent abrasion during crashes), it has always been bulky and hot to pedal in. In the past, pretty much no one other than downhillers would wear armor.
But we are now starting to see more and more mountain bikers wearing light protection. The introduction of readily available non-Newtonian gels (materials that stiffen with rapid application of force) has allowed manufacturers to produce lightweight and flexible pads that stiffen on impact, providing a large amount of impact absorption from a minimal amount of padding.
G-Form was the first company to capture a significant part of the market with their Pro-X Knee and Elbow Pads, which then influenced consumers to seek out other lightweight, low profile pads that still offer substantial protection. When Leatt released their 3DF Airflex line of body guards, I was excited to see how their non-Newtonian, slim pad offerings performed.
Test Goals
I usually don’t wear pads while trail riding because I find them to be too hot and uncomfortable, and (thankfully) I don’t crash very often. The 3DF Airflex guards fit me so well and have such good ventilation that I was excited to see if I could wear them almost all the time while riding.
I was also excited to see that the 3DF Airflex pads received an EN1621-1 certification. EN1621-1 is a European standard for shoulder, elbow and forearm, hip, tail-bone, knee and lower leg pads for motorcycle use, and requires that a pad be able to attenuate specific impacts to a certain extent.
To geek out for a moment, pads tested to the EN1621-1 standard have a 5kg mass with a 40mm x 30mm impact surface dropped onto the pad from a sufficient height to provide 50J of energy at impact. The pad is mounted onto a 50mm radius spherical surface, and passes the test if the average force transmitted through the pad on nine tests is <35 kilonewtons (kN) and no test exceeds 50kN.
The Leatt pads are the first low profile pads that pass this test. What I am not certain of is whether that means other companies just haven’t sought out the certification, or if many have tried and failed.
The test means that in an ideal situation, the gel can do a great job of attenuating impacts, but I also was curious to see whether the 3DF Airflex guards could stay in place well enough to let the gel do its job during a crash.
Fit
The 3DF Airflex knee and elbow pads are sleek, with carefully contoured gel pads that fit the body well. On me, the knee pads fit perfectly, while the elbow pads had a decent fit. The knee and elbow pads are open on the back to allow airflow, and the pads are perforated to also help move air.
The sleeves on the knee and elbow pads are a lightweight wicking fabric. Leatt added a strip of silicone to the upper cuff of both the knee and elbow pads to keep them from slipping down. Silicone strips are also placed on un-anchored internal fabric to form knee and elbow cups that keep the pads tracking with one’s joints.
The smooth and low profiles of both the knee and elbow pads allow long shirt sleeves or long shorts to easily slide over the pads, and they don’t catch. Additionally, the pads’ long sleeves meant that I could wear shorter riding shorts or shirts without fear of exposing an awkward stripe of pale flesh.
Performance
The 3DF Airflex guards were light enough that I never noticed the extra weight while riding. The open back on the knee and the open inside on the elbow did a great job preventing sweat from building up. While I can’t say I felt any noticeable airflow through the perforations in the guards, they were cool enough to wear in situations where I would have shed most other pads. I’d say that they aren’t quite as warm as a knee or arm warmer, but are not that far off.
The 3DF Airflex knee guard fits well with different layers; I slipped the top of the sleeve under my spandex shorts as I would a knee warmer and never once had the pad slip down. Even when I crashed directly on my knee, the pad stayed in place.
When riding, I often forgot I was wearing the pads, and I only noticed them when it was above 65ºF and I wanted to start shedding layers that kept heat trapped. In warmer temps the gel made the pads feel a bit clammy, but it wasn’t terrible and I’ll continue to wear them as long as temperatures aren’t much higher than 70ºF.
The elbow pads fit reasonably well, but did not feel as good as the knee pads. The wrist opening felt too tight, while the bicep opening was appropriately sized, so I’m guessing that a larger size probably wouldn’t work for me.
Leatt has a detailed chart on their site indicating what measurements to account for when choosing your side, and I’d recommend referring to that. Also, the pad flexed quite a bit as I bent my elbow. It stayed in place, but that feeling caught my attention and felt a little odd.
In the hardest crash I took wearing the 3FD Airflex guards, I lost traction while riding around a banked corner at speed and fell directly onto my right knee and elbow. The pads did a great job of preventing abrasion and absorbing the impact, but I did catch a rock on the side of my leg, just below the knee, that was outside the padded area. The thin sleeve material offered almost no protection and actually tore a little. In that area, I was left with a bit of road rash and a bruise. It wasn’t too painful, but served as a reminder that these don’t cover quite as much area as bulkier, more traditional pads.
I really like the 3FD Airflex knee guards and have been really impressed with the fit. So far, the small tear hasn’t enlarged, and I expect that I’ll be able to get at least one or two more seasons out of them. While I plan to wear a bulkier set of pads if I am going to be riding anything challenging and rocky, I ended up wearing pads more often than I would have otherwise due to the 3FD Airflex’s light weight and comfort.
The elbow guards fit pretty well, but I’d love to see Leatt improve the articulation. I noticed the elbow pads while riding much more than I noticed the knee pads, and I occasionally found that I needed to adjust them. If you’re worried about falling on your elbows I’d still recommend them, but I don’t anticipate wearing them anywhere near as frequently as the knee pads.
Bottom Line
The Leatt 3DF Airflex knee and elbow guards are comfortable, offer great protection for their size, and stay in place well. I’d suggest them to anyone riding both up and down who doesn’t want to have to take their pads off on climbs.