SixSixOne have just released some seriously lightweight, flexible, breathable D3O elbow and knee pads for mountain biking. Thanks to the new D3O Ghost Pad, the 661 Recon D3O pads are, by a country mile, the most flexible knee pads we’ve tested yet. For mellow trail and XC riding, these compete strongly with some of the best on the market, but they aren’t without their limitations. I’ve been putting them to the test over the last month on my local loam and hard-pack XC trails; here are my thoughts.

Review: SixSixOne Recon D3O Knee Pads

First up, it would be wrong of me to compare these with a full-on enduro or DH knee pad. What 661 have produced here is a lightweight, flexible knee pad that can be slipped on for that extra peace of mind before heading out for a ride. It’s the terrain of that ride that needs to be considered. Why? While they are largely very comfortable and breathable and offer some protection from impacts, they aren’t going to be appropriate for every ride. We’ll get to that in a minute. First, here’s a quick overview. 

661 Recon D3O Knee Pads

• D3O Ghost Insert offers impact protection
• Silicone Grippers prevent slippage
• Padlock System provides connectivity with 661 EVO Short
• Lightweight
• Ultra-Flexible
• Machine Washable

Photo by Will Cheskin

The 661 Recon D3O pads are of a basic slip-on design. Above and below the D3O Ghost pad is a thin, elasticated material that hugs the thigh and calf comfortably. At each end there’s a silicone strip that grips your skin to prevent the pad moving up and down as you pedal. The fabric itself is super breathable, and there’s even a big hole at the back of the knee to provide extra ventialtion. 

Fit & Comfort

Photo by Will Cheskin

The SixSixOne Recon D3O pad sits very high up on the thigh; much higher than any knee pad we’ve worn previously. The top-gripper is meant to sit at the mid-thigh point – this is where you should measure your thigh circumference when picking a size. This is great in terms of preventing the pad from moving during an impact; there’s more surface area to grip at the mid-point of the thigh than lower down.

But, it does mean that the top silicone gripper will likely be competing for space with whatever chamois liner shorts you may be wearing. If you do find there’s overlap, I’d recommend you prioritise the fit of the pads over the chamois – it’s important that the silicone gripper interfaces with your skin so that it has a strong purchase.

At the top of the pad, outside edge, there’s a popper that allows you to connect the Recon D3O pad to SixSixOne’s EVO Short. This is their Padlock system, another design feature aimed at preventing the pads from slipping down the leg as you ride, or getting pushed down off the knee during an impact. It’s important to bear in mind that this will only work if your thigh is sufficiently long enough that there isn’t significant overlap between the EVO Short and the top of the knee pad. I’m a little on the shorter side (163cm) so the overlap for me was pretty large.

Photo by Will Cheskin

I’m happy to report that the 661 Recon D3O pads were largely very comfortable. I really liked that the pad itself extends quite low, covering a decent portion of the shin too. On rides lasting around 2 hours, I barely noticed their presence at all.

Photo by Will Cheskin

The flexibility of the D3O Ghost pad makes for entirely unhindered movement throughout the pedal stroke. It was only on longer, 3 hour + rides, especially on hot days, where I noticed some friction. The offending part of the pad was the seam at the ventilation hole; this started to rub a little at the inside of my knee.

What rides are the Recon D3O Knee Pads most appropriate for?

Riding a blue-graded flow trail at Glentress Trail Centre, Scotland. Photo by Will Cheskin.

This is key. You don’t want to rely on these for protection if you’re riding hard and pushing the limit on trails littered with chunky rocks or sharp gravel. That’s because the D3O Ghost insert isn’t homogeneously solid. It is composed of a flexible lattice of intercalated triangles with gaps in between. This is what gives the pad its incredible flexibility, but it does undeniably sacrifice some protection. 

That said, I’d be happy to recommend these knee pads for loamy trail rides, or rides where the surface is largely smooth hard-pack. Personally, I’ve chosen to wear these pads on warmer days throughout the summer, for chilled social rides on our local steep loamy trails. ...

Photo by Will Cheskin

The SixSixOne Recon D3O Knee Pads are available in sizes S-XL, covering thigh circumferences of 40-60cm. There is also a Recon D3O Elbow Pad available in sizes S-XL, covering bicep circumferences of 28-40cm.

The SixSixOne Recon D3O Knee Pads weighing 311g in Medium