Trek Ballista Mips helmet

Trek's Ballista Mips is a lightweight aero road helmet that offers impressive cooling for such a small amount of venting. The retention system is easily adjustable, giving a great fit, and you get the bonus of Mips tech too. Like most aero helmets it's not cheap, but it is competitively priced against some of its main competitors.

For more options, check out our guide to the best aero helmets.

Aero gains, marginal gains... if you need them you're going to be looking for an aero helmet to go with your aero bike and your deep-section wheels. Unless you are a time-triallist or triathlete, though, where the aerodynamics are the most important factor over comfort and cooling, you are going to want something like the Ballista which offers a blend of them all.

> Buy now: Trek Ballista Mips for £229.99 from Trek

Trek says the Ballista is its fastest, most aerodynamic helmet. How fast? Well, without a wind tunnel that is pretty much impossible to say, and I am not going to sit here and talk about how I was so many seconds quicker over this section than when wearing a different helmet as there are just so many variables at play.

> Should you buy an aero road helmet? How much faster could you be?

When hunkered down in the drops as low as I could go, I did find the Ballista sat well, with the aero tail flat towards my back, and the front allowing good vision for looking forwards.

The dial system for adjustment uses just a small plastic section at the back, as opposed to a band running all the way around the sides of your head like on most top-end helmets. Here the helmet has a Boa wire (just like the Boa system on your shoes) to adjust the fit, and it does that with no pressure at all which makes for good comfort, as well as plenty of adjustment.

Attached to the main EPS section of the helmet you'll find the Mips Air system. It's a cradle lining the inside of the helmet and is a lightweight system that reduces the rotational forces that would otherwise be transmitted to the brain during impact from a crash.

> All you need to know about Mips

With the Air system, the technology has been built into the padding, and according to Mips it allows 10-15mm of movement in relation to the EPS section of the helmet. If you didn't know what you were looking for, you'd never see it as the whole setup is very discreet.

To keep things smooth, the Ballista has very few vents – just four in total – but their shape is designed to scoop in as much air as possible, and the helmet does draw a fair chunk of air through. You can feel it flowing over your head, and exiting via scoops out of the rear.

For the majority of the review period the weather was pleasant and early rides took place with the temperature around 20°C. The Ballista coped fine with hard riding in this sort of warmth, with that airflow passing through the vents. As the thermometer climbed up towards 30°C a few weeks later, though, I found the conditions too warm to wear it comfortably, especially when on a long drag or even a short, sharp climb. With minimal air blowing through at lower speeds, it did become quite stifling, the black finish probably not helping.

I'd say that up to about the mid-20s the aero advantage is worth the compromise on the heat, but above that I'd switch to a vented helmet to keep cooler. The Ballista isn't really a helmet I'd grab in the middle of a heatwave.

For an aero helmet the weight is impressive, though even the chunkiest of aero helmets tend not to be heavyweights. It comes in three sizes, with this medium (54-60cm) weighing in at 271g on our scales. The small fits 51-57cm head sizes, and the large 58-63cm.

The overall quality is to a high standard and it's good to see the outer liner wrapping itself around any exposed EPS to reduce accidental damage from drops and the like. The two front vents that sit either side are spaced to accept your sunglasses arms too.

Value

As for price, the Ballista has an rrp of £229.99 which isn't exactly a bargain, but then again, not many top-end helmets are. Against the competition it's actually quite competitive.

Specialized's S-Works Evade 3, which I tested last year, also uses Mips and the weight is virtually identical. It costs a fair chunk more, though, at £275, while the Kask Utopia Y that I tested last month sits somewhere in between the two at £245.

There are some cheaper options, though: the HJC Furion 2.0 that Ed tested last year is 'just' £180. It's quite a bit lighter, too, at 218g.

Conclusion

If you are after an aero helmet for road cycling then the Ballista Mips does a great job. It's a slimmed-down but similar sort of design to many time trial aero helmets, but with impressive airflow for the number of vents and without being hugely heavy. It's priced competitively too.

Verdict

Comfortable and surprisingly breezy aero helmet that is well priced against the opposition