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Bell 4Forty MIPS Review

The affordable Bell 4Forty MIPS is a quality helmet and the winner of our Best Buy Award.
Best Buy Award
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Price:  $95 List | $71.21 at Competitive Cyclist
Compare prices at 2 resellers
Pros:  Reasonably priced, comfortable, innovative sweat management system, MIPS, adjustable visor
Cons:  Moderately heavy, ventilation could be better
Manufacturer:   Bell
By Jeremy Benson ⋅ Senior Review Editor  ⋅  Apr 10, 2019
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#7 of 11
  • Protection - 25% 8
  • Comfort - 20% 8
  • Ventilation - 20% 8
  • Features - 15% 7
  • Weight - 10% 7
  • Durability - 10% 9

Our Verdict

The 4Forty MIPS falls squarely in the middle of Bell's range of half-shell mountain bike helmets and is one most affordable models in this test. Despite the reasonable price, the 4Forty scored competitively across our scoring metrics and is the hands down winner of our Best Buy Award. This helmet offers excellent protection with Bell's Fusion in-mold polycarbonate shell bonded to the EPS foam liner, good coverage, and an integrated MIPS system. It has 15 vents and offers solid ventilation performance, plus it has an innovative sweat management system that helps prevent sweat from dripping on your lenses. The quality adjustable visor is goggle compatible and other adjustment points, like the straps and fit system, are well executed. This helmet easily outperforms many of its more expensive competitors.

Compare to Similar Products

Our Analysis and Test Results

Bell has been making cycling helmets for decades and the 4Forty MIPS is one of several half-shell mountain biking helmets in their lineup. We tested a similar version last year called the Hela Joy Ride which was a women's specific version of the 4Forty. Bell now longer offers it. Instead of making separate men's and women's models, Bell now just makes the unisex 4Forty in a large range of colors, including some that are on the feminine side.

We liked the Hela helmet when we tested it last year, and that trend continues with the 4Forty this year. This affordable model offers an excellent combination of comfort, protection, adjustability, and style that far exceed the asking price. You'd be hard pressed to find a better helmet at this price.

Performance Comparison

The 4Forty easily claimed our Best Buy Award.
The 4Forty easily claimed our Best Buy Award.


The 4Forty MIPS offers a pretty high degree of protection. It's a half-shell helmet with good coverage of the temporal and occipital lobes, and it has a relatively deep fit that wraps around the head nicely. Bell has employed their Fusion in-mold construction, which means the outer polycarbonate shell is bonded to the inner EPS foam liner. They claim this makes for a sturdier helmet, and we'd have to agree. This helmet feels solid with no noticeable gaps between the shell and liner. They've also included a MIPS liner in the 4Forty, which works like a slip-plane and is intended to help reduce the forces of oblique impacts in the event of a crash. The Float Fit retention system is integrated into the MIPS liner. When the fit adjuster is snug enough, it wraps around the head securely while the helmet floats around the liner.

While we are quite impressed with the protection the 4Forty offers, a couple of helmets in our review have even more coverage. Both the POC Tectal Race SPIN and the Specialized Ambush with ANGi have slightly deeper fits and coverage on the temporal and occipital lobes. The majority of the other competitors, like the Grio Montaro, Oakley DRT5, and Smith Session, have roughly the same coverage as the 4Forty.

The 4Forty has a relatively deep fit and good coverage all around the head.
The 4Forty has a relatively deep fit and good coverage all around the head.

We're a fan of MIPS, and it is widely considered to be the industry standard rotational impact protection system. We think that a MIPS liner is far better than none at all and a great protective feature for a helmet at this price point. There are several other rotational impact protection systems on the market, including POC's SPIN, Leatt's Turbine 360, and 6D's ODS, all of which claim to provide a slip-plane like MIPS while also absorbing impact directly.

The MIPS liner in the 4Forty is black and is connected to the fit adjustment system.
The MIPS liner in the 4Forty is black and is connected to the fit adjustment system.


The 4Forty scored well in our comfort rating metric. It's not the most comfortable helmet in the review, but it's no slouch either. The length, width, and depth of the helmet are good and should be compatible with a wide range of head shapes.

It has thin but well-placed padding across the brow to the temples and a little on the top of the head. The fit adjustment system also offers plenty of range to snug the fit around the head. The fit system can also be adjusted up or down on a small internal ladder to position the cradle in the perfect spot for your comfort. Testers did find the small dial on the fit adjustment to be a little less user-friendly than larger dials on other models, but it works. The strap system is relatively basic but offers plenty of adjustment, and the splitters by the ears do a great job of holding the straps flat, so they don't conflict with your ears. The helmet is relatively well ventilated, which helps to keep you from overheating on hot summer days.

The Float fit adjustment.
The strap splitter is nothing special but we found easy to use and relatively comfortable.

We generally loved the fit and comfort of the 4Forty, but it couldn't quite match that of our highest rated helmets. The Specialized Ambush with ANGi is one competitor that tops our comfort rating charts due to its incredibly light weight, great ventilation, 360-degree fit adjustment, and padding that makes it disappear on your head. The 4Forty scores equally for comfort with many of its more highly priced competitors, however, like the Smith Forefront 2 and the Oakley DRT5.


The ventilation of the 4Forty is surprisingly good. It can't quite match the highest scorers in this metric, but its performance is solid. It has 15 total vents as well as some internal air channels that allow air to pass from the front to an exhaust vent in the back. The vents are well placed, medium in size, and none of them are blocked or impeded by the MIPS liner inside. While it isn't the best in the test, testers found it to be adequate and effective in all but the hottest of conditions. If or when you do get sweaty, it has the sweat guide pad in the front of the helmet which effectively pulls sweat out away from the face.

One of our top-rated helmets for ventilation, the Specialized Ambush with ANGi has 20 total vents and well designed internal channels that move significantly more air around the head than the 4Forty. The Troy Lee A2 and Smith Session are also well-ventilated helmets, with larger forward facing vents that promote more air movement than the 4Forty.

The ventilation on the 4Forty works better then we expected it to.
The ventilation on the 4Forty works better then we expected it to.


The 4Forty comes equipped with a number of features that are intended to enhance its protection, comfort, and user experience. As mentioned above, it has a MIPS liner to provide rotational impact protection as well as Giro's Roc Loc Air fit adjustment system. The straps are also adjustable by the ears and below the chin to further dial in the fit to your preferences.

One of our tester's favorite features on the 4Forty is the Sweat Guide system. This unique sweat management system is a small tab of padding attached to the brow pad that extends forward at the center of the brow of the helmet. In our experience, the sweat channels through the brow pad and out to the pad extension where it drips in front of your glasses and is far less prone to landing on your sunglass lenses or running down your face. No other helmet in our test manages sweat quite as effectively as this, although the Oakley DRT5 deserves an honorable mention with their rubber sweat gutter system.

The sweat guide system sounds like a gimmick but it actually works really well.
The sweat guide system sounds like a gimmick but it actually works really well.

The helmet also has an adjustable visor that folds up high to accommodate goggles and can be positioned anywhere in its travel between the full up and down positions. This visor is quite similar to those found on other helmets like the Giro Montaro or the Smith Forefront 2, all of which are far more user-friendly than the non-adjustable visors on the Liv Coveta MIPS and the Troy Lee A2.


Our size large test model weighs in at 406 grams or 14.32 ounces. It's not exactly lightweight, but its also far from heavy. Considering the price, we feel that this weight is quite acceptable and not that far off of many of the other helmets in this review.

The Giro Montaro weighs almost the same as the 4Forty, just six grams less, while several other helmets in our selection are 20-30 grams lighter than both of those helmets. Our lightest weight competitors, like the Specialized Ambush with ANGi weighs just 350 grams and feels featherlight in comparison. On the other end of the weight spectrum, the 4Forty is significantly lighter than the Oakley DRT5, 70 grams lighter as a matter of fact. That difference in weight is noticeable both in your hand and on your head. The 6D ATB 1T Evo is our heavyweight champ, weighing a whopping 109 grams more than the 4Forty.

A 406-gram helmet won't satisfy the gram counters of the world  but it's just fine for most people  especially considering the price of this helmet.
A 406-gram helmet won't satisfy the gram counters of the world, but it's just fine for most people, especially considering the price of this helmet.


Bell's Fusion in-mold construction is one reason the 4Forty appears to be a very durable product. The outer polycarbonate shell is bonded to the inner EPS foam and wraps fully around the bottom edge of the helmet. There are no gaps between the shell and the liner, and the only EPS foam showing is on the inside of the vent holes, where it isn't very susceptible to damage. We never took any hard crashes while wearing the 4Forty, but we did treat it as if it were our own and tossed it into the back of the truck, the trunk of the car, and the bike gear bag quite often. It appears no worse for the wear. The visor is still straight and completely functional, the fit adjustment system is in perfect working order, and everything is as it should be. The only real evidence that we used the helmet at all is the salty sweat stains on the chin strap.

The 4Forty scores with the top rated models for durability. There are a number of other helmets in this review that share a similar wrap around the shell that protects the more fragile EPS foam around the bottom edge. Helmets that scored lower in this metric, like the Specialized Ambush have more exposed EPS foam that is susceptible to damage, or they just feel lighter and more fragile overall.

Best Applications

We feel the 4Forty is well suited to virtually any type of mountain biking. Trail, all-mountain, XC, or light duty enduro style riding are right up this helmet's alley. We wouldn't recommend it for riding lifts at the bike park, and gram counting riders might be more inclined to find something a little lighter, but for everyone else, and especially the rider on a budget, this is a great versatile helmet.

The 4Forty is a solid affordable option for all-around trail riding.
The 4Forty is a solid affordable option for all-around trail riding.


At a very reasonable retail price, the 4Forty is an excellent value and a shoo-in for our Best Buy Award. This helmet punches above its weight class and is as comfortable and feature-packed as most of its more expensive competition. We would absolutely recommend this helmet to the rider on a budget, and to any other rider for that matter.


Bell impressed us with their affordable 4Forty mountain bike helmet. It offers solid protection, a comfortable fit, and pretty good ventilation. Features like an adjustable visor, an effective sweat management system and comfortable straps add to its user-friendliness. If you're on a budget, and even if you're not, we think you'd be hard pressed to find a better helmet at this price.

We liked the 4Forty  especially considering the price. It's our Best Buy Award winner.
We liked the 4Forty, especially considering the price. It's our Best Buy Award winner.

Other Versions

The 4Forty comes in eight different colors including the Cliffhanger Matte-Gloss Greens colorway we tested, so you can be sure to match your bike or riding kit. The next model up is the Sixer ($150) which comes MIPS equipped with 26 vents and a similar look to the 4Forty.

Jeremy Benson