Our reviews of mountain bike helmets focus on the five criteria most bikers are looking for in a new helmet: comfort, ventilation, features, fit and weight. We don’t test protection because there are plenty of testing facilities and laboratories doing these very controlled tests. We do confirm that all helmets have met basic safety certifications and we test them in their practical use—everything but the crash.
A helmet is the one piece of equipment that cyclist should never scrimp on. It’s the protective layer between the skull and either the ground or trail objects and can be the dividing line between a severe or life-ending injury and enjoying many years of riding. After riding with five different mountain bike helmets, our tester ultimately selected the Specialized Ambush as the Best in Class due to its bang for the buck. At $180, it offers outstanding head coverage, a generous sun visor and superior ventilation, the best of all the helmets in the test. On the opposite end of the price spectrum were the MIPS-equipped Trabec Race and Bushwhacker which each cost $230. So how important is MIPS? As our tester did not test impact, it’s difficult to say. But with MIPS-equipped helmets on the market priced well under $100, the pro-MIPS, cost-conscious cyclist certainly has options.
A key feature of the Ambush that helped contribute to it score was the visor, which was the most impressive of all the helmets tested. It measures four inches in length from the longest point in the center and offers the most sun shading as well as the widest range of adjustability thanks to a channel of micro-notches in the visor’s center that allow for adjustments via a series of micro-clicks for best position. Most often, this range of adjustability is only seen on downhill helmets, which the Ambush is definitely not. The only point of contention our tester found with the Ambush was the unadjustable Tri-Fix web splitter. Although its factory setting fit our tester very well, that might not be the case for others. Below are detailed side-by-side comparisons specific to each of our testing criteria.
Scoring the highest in this category, with eight points, was the Troy Lee Designs A1 Reflex. Its plush and generous stock padding that covered every point of potential contact. After a six-hour road ride or a 15-mile mountain bike ride, our tester felt no pressure points or need to adjust. The side straps, which are composed of one thin strand of webbing, are spaced far enough apart at the helmet junction to not touch or chafe ears. Padding was also excellent in the Bushwhacker, which scored seven points. The two large and small perforated strips do a very good job of absorbing sweat, making this another comfortable helmet on long-distance rides. However it scored a point lower than the Troy Lee Designs A1 Reflex due to its thicker straps, which retained moisture.
With a score of six, the Trabec Race placed third. Soft padding at the front of the helmet that runs approximately three quarters toward the rear of the helmet made it comfortable for any length of ride. Although it did a decent job of absorbing moisture on mid-temperature days, it did come up short on warmer, high-exertion days. Side straps, once properly adjusted, laid flat on our tester’s face without making contact with ears. The chin strap, though composed of thicker webbing, sat comfortably under the chin but needed the occasional re-tightening.
The Specialized Ambush and the Smith Forefront’s comfortable and lightweight side and chin straps earned them each a score of five. The Ambush is composed of one thin strand of webbing that allows for only one piece of webbing under the chin instead of the usual two. The Tri-Fix web splitter spreads the two upper lengths of webbing into a wide U-shape (instead of a standard V-shape), which prevents the straps from touching the ears. The downside to the Tri-Fix web splitter, though, is its lack of adjustability. On the Forefront, the strap webbing is thin and lightweight and lies comfortably flat. However, our tester found that the side straps are placed too close together where they come out of the helmet and frequently touched her ears. Padding in both the Ambush and the Forefront consists of two thin and narrow strips that run front to back. On the Ambush, it is simply one large forehead piece and one separate piece at the top of the head. Though on the minimalist side, the padding for both helmets is perforated and does a decent job of preventing sweat from dripping onto the face.
With 20 air vents that did an outstanding job of air intake, the Specialized Ambush was the undisputable winner in this category with eight points. Six rear vents, generous in size, easily pushed out warm air for optimal comfort on our tester’s head. The Sweet Bushwhacker MIPS’ 17 air vents also did a good job of promoting air flow, earning it a score of six. However our tester found that on mountain bike rides in excess of 12 miles with temperatures ranging from the low 60s to mid-70s, ventilation came up short due to the MIPS liner. With 16 well-placed air vents, the Troy Lee Designs A1-Reflex scored five points. Although the air vents worked well, even when sitting idle or moving slowly up a climb, the generous and plush padding tended to hold more sweat than the other helmets in the test. Cyclists who live in geographical regions with humid summers will notice this limitation the most.
Scoring four points each were the Smith Forefront and the POC Trabec Race. Although the Forefront has 21 air vents, our tester found that it did not translate to optimal ventilation on high-exertion rides due to the honeycombed sheet of Koroyd tubes. The downside to this innovative safety feature is that it reduces ventilation and out tester found it most noticeable on 70 degree days on hilly mountain bike trails where greater exertion was required while riding slower speeds. However, ventilation worked better on road rides with increased speed that did not involve steep technical climbs. With 14 air vents, the Trabec Race offers greater surface space at the expense of ventilation. Our tester experienced the best ventilation on days with temperatures in the high-60s and on rides that did not require excessive steep hill climbs.
Each of the helmets had unique features that promoted safety such as technology and surface space. The top scoring helmets were the Specialized Ambush, Sweet Bushwacker, Smith Forefront and the POC Trabec Race, which tied at seven points each. The Ambush’s key to safety was an Aramid-reinforced skeleton for internal EPS support and Energy Optimized Multi-Density EPS construction to manage impact energy. It also has the most surface space of all the helmets, with a measurement of 17.5 inches in length and 15 inches in width The Forefront offers Koroyd technology for impact protection, which uses thousands of thermally-welded miniature tubes that absorbs impacts by elastically deforming. Coverage is also very good with surface space measuring 17 inches in length and 14 inches in width.
The Bushwacker and the Trabec Race represented the two MIPS-equipped helmets in the test. MIPS is a thin liner that protects against rotational forces by separating the shell from the liner to allow the liner to slide relative to the skull in an angular crash. Additional head protection for both helmets is a surface space 17 inches long and 14 inches wide on the Sweet Bushwacker, and 16 inches long, 4.4 inches wide on the Trabec Race. With a score of six points, the Troy Lee Designs A1 Reflex offers a polycarbonate shell in-molded with EPL liner and excellent head coverage at 17 inches long,14 inches wide, providing excellent head coverage.
The highest scorer here was the Troy Lee Designs A1 Reflex with eight points. Its single glove-friendly dial at the back of the helmet made adjustment fast, simple and doable while riding without losing balance. But the biggest reason for its high score is that once the side straps were properly adjusted, it had a snug and comfortable fit with the least amount of wobble on our tester’s head. With a score of seven was the Smith Forefront. Its Smith VaporFit dial-operated 360 degree adjustable fit system was also very easy and fast to adjust, and could be done one-handed while riding, although wearing gloves made this a little more challenging due to the dial’s smaller size. Like the Troy Lee Designs, it had a snug fit. But it did have a slight wobble, likely due to the thin padding. The most glove-friendly adjustment system was the Sweet Bushwhacker’s four-way Adjustable Turn-Dial Occigrip fit system, which earned six points. Adjustment is fast and can be done one-handed while riding. Our tester found that the thicker padding included with the helmet was needed for a secure fit.
With five points, the Specialized Ambush’s Mindset 360 degree fit system turned out to simple and fast to adjust and out of the box, the tester had only to tighten the chin strap and adjust the rear tension dial for a secure and customized fit. Unfortunately, the Tri-Fix web splitter’s factory setting is not adjustable. Although it fit our tester very well, this could be an issue for other cyclists. The Trabec Race, scoring four points, had the most challenging fit of all the helmets in the test. The size XS/S measures 51-54 cm and our tester’s head measured 54 cm, putting it at the maximum size for the helmet. But when our tester tried on the M/L (55-58 cm) model it was too large. The size XS/S felt as it was slightly suspended above the head but our tester was able to mitigate the suspension feeling by spreading the rear adjusters as far as possible and then holding them apart while putting on the helmet. The backband adjustment is a two-slider system that can be adjusted one-handed while riding, though not as simply as the dial method. But once fit was dialed in, the Trabec Racehad a very secure, snug fit with the second least amount of side-to-side wobble.
Looks were deceiving with the Specialized Ambush in the weight department. Despite its generous head coverage, it was the lightest helmet at 293 grams, earning it a score of nine. With a score of seven, the Smith Forefront was the second lightest helmet at 310 grams. Although it has generous head coverage and the Koroyd sheet safety feature, its thin strap webbing was likely the key to its svelte weight.
The heavy hitters were the Troy Lee Designs A1 Reflex, Sweet Bushwhacker MIPS and the POC Trabec Race MIPS, each scoring five points. At 331 grams, the Troy Lee Designs was the second heaviest helmet. With thick webbing, extensive surface space, a sturdy plastic retention strap and generous padding, it is not a helmet for the weight-conscious cyclist. The POC , with its generous head coverage, sturdy straps and MIPS liner weighed in at 327 grams. But the heaviest of them all was the Sweet, which tipped the scales at 365 grams. Though despite this weight, it felt surprisingly light on our tester’s head.
Our tester focused entirely on the helmet’s day-to-day ease of use, logistics and all the elements that contribute to comfort and fit, such as ventilation and weight. Features were also considered, such as the helmet’s capacity to protect the cyclist’s head upon impact. Our tester did not test a helmet’s impact protection. The helmets were tested while riding on asphalt, gravel, and singletrack in and around Minnesota on days with temperatures ranging from the low 40 to the mid-70s and on distances that ranged from 6 miles to 56 miles.