Mavic Plasma Road Cycling Helmet offers elite-level performance to any discerning cyclist. Optimal cooling, incredibly lightweight and aerodynamic. Optional visor is included. Sleek, well ventilated construction with 20 Clima Vents for optimal cooling. Alutex reinforced for optimal strength and ventilation. Weighing in at only 285 grams (medium).
Strengths: Great fit, comfort, ease of adjustment, solid construction, styling, visor included
Weaknesses: Expensive, heavy, marginal ventilation, sizing is inaccurate, adjustment loosens with a light bump, chinstrap loosens constantly, sloppy detailing
My helmet is identical to the one in the picture. My comments are relative to my other road helmet, a Bell Sweep.
Mavic concentrated on the fit and I would say they nailed it. The Plasma fits great and it's very comfortable, which is what convinced me to buy it. The padding is firmer than in other helmets I've owned and you may notice that at first, but I got used to it quickly.
The adjustment knob turns with a very light touch, which is both good and bad. While it's very easy to adjust, a slight bump will cause it to loosen. If you wear anything under the helmet that has a knot or adjuster on the back, it may bump the helmet adjuster and cause it to loosen. For some reason, the chinstrap loosens on every ride. These adjustment issues are potentially dangerous if you don't check them regularly (this is not a "set it and forget it" helmet).
The sizing runs very small. According to Mavic, I could wear either a size medium or large (22 1/2" head circumference), but the large is barely big enough. Try it before you buy it!
Unlike many helmets, the shell on the Plasma looks and feels substantial, reassuringly so. The rest of the construction is excellent, but some of the finishing touches were sloppy. Incorrectly-placed Velcro pieces caused an annoying bump in the top of the helmet and stuck out from behind the pads in some places. Repositioning them solved the problem. Two of the many stickers inside the helmet came loose, as did the one on the rear center ridge. Some of the exterior stickers weren't even installed on my helmet, but it's not as if I miss them.
One downside to the solid construction is that the Plasma is pretty hefty for a high-end helmet. My large weighs 385 grams without the visor, which is 20gr. more than the label in the helmet specifies and ~70 grams more than the Sweep.
The helmet is much quieter than the Sweep, but there is noticeably less airflow through it. Once the temps get beyond 75F or so, the ventilation is inadequate. This is a major disappointment and it means that the Plasma will be relegated to fall/winter/spring use only.
The MSRP ($180) is pretty ridiculous and dealers don't seem to discount them, but they're available on Ebay for $115-$120, which is at least semi-reasonable.
Overall, it seems that Mavic concentrated too much on the fit and seriously missed the mark on other important elements, particularly ventilation, weight and the function of the adjustments. Combined with the high price, there is no way I can recommend the Plasma, as there are better helmets available for less money. Taken in total, it's a disappointing package.