Sometimes, the littlest things make the biggest difference. Hydration mix concentration is the difference between bonking and bloated. Traction can be affected by tire pressure differentials as low as 5 psi. With a bike fit, being off by millimeters is the difference between suffering on the long course and total comfort. After spending many, many miles with Oakley’s new Radarlock XL sunglasses, we’re convinced that we can add 7mm of lens as the difference between perfect clarity and neck cramps, too.

The Radarlock XL’s extra 7mm really doesn’t sound like much; but the difference in sight picture in the aero position simply cannot be overstated. We noted in our First Ride that if we ducked our head enough to touch the tail of an aero helmet to our shoulders that we could just barely see the frame as an orange haze at the top of our vision. Well, we’re happy to report that, on our most recent ride, we honestly didn’t notice it at all – we simply had a completely unobstructed view of the road out in front of us no matter how aggressive a head and neck position we chose. This was a gradual adaptation on our part. We had become accustomed to the position of the glasses, as well as fitting the slightly taller nosebridge. Thus the top of the frame went from a noticeable haze at the top of our vision to something we had to consciously look for when riding. Also, we did notice the venting on the top of the lens, so the frame certainly wasn’t far off. But of course there is only so much room between the forehead lip of an aero helmet. And that space is a very real hard limit to how much lens you can have in a pair of sunglasses and still strap on a helmet, and the Radarlock XL fills it nearly completely for us without having to go to an integrated-optics setup. For our money, we’ll take the Oakleys.

One of the big reasons we prefer non-integrated optics is that it affords you options in what you’re putting between your eyes and the road. The Radarlock XL has, as of this article, three models with a total of five lens options between them, all of which are vented and one of which is polarized. Our review model (Fire Iridium Polarized) has been discontinued in favor of the new Oakley OO Red Polarized lens, which promises better contrast and enhanced color reproduction.

We would also like to note that, to our best efforts to find another option, Oakley does appear to be the only company offering polarized lenses in triathlon/cycling-specific frames – something that should be commended, as it cuts down on eye strain when out on the course. We have enough issues on the bike without adding glare to the mix.

As noted by other outlets, Oakley only applies hydrophobic coating to the outside of the lens, which means that sweat can, and does, streak a little on the inside lens if out on a hot day. This isn’t such a big deal, as the rimless nature of the lens clears the sweat by gravity when given the chance. But if it bothers you, you can purchase Oakley’s hydrophobic coating kit for just $20. The solution is as simple as it gets to apply—clean the lens, use the pen to coat the lens surface, wait 30 seconds, and buff it off. No more sweat streaks on your lenses ever again. And if it comes back, the kit is supposedly good for “about 50 applications.” Not bad for $20.

In fact, the only thing we don’t like about the Radarlock XL is that the frames won’t accept standard Radar or Radarlock lenses; there’s no inter-compatibility between them at all. If you like the current Radar, but wish you had a taller lens for TTing, you’ve got to buy a whole new optic system just for that. Again, this isn’t such a big deal, as we already do that between road and TT/Tri, but it does add one more glasses case to our collection. The price tag isn’t exactly minor either – $220 for standard lenses and $300 for the polarized kit.

Still, the Radarlock XL is possibly one of the most complete solutions for the triathlon and cycling communities. It could easily supplant your entire collection of optics in favor of a single frame and a handful of lenses to deal with different conditions. Their visibility is also second to none, and the ability to interchange lenses is a huge benefit to those of us who have to get our training in when lighting may not be ideal.

So if you’re having trouble seeing over your sunglasses while in the aero position, or need a system that lets you change it up now and again, look no further than the Oakley Radarlock XL. We think you’ll be pleasantly surprised; we certainly were.