1. Alpinestars KMX-9 S V2

You might not be challenging Lewis Hamilton for the championship just yet, but with the Alpinestars KMX-9 S V2, you’ll at least be matching his karting suit technology. This flagship model sits at the pinnacle of karting apparel, and it shows in every carefully considered detail.

During our 4-hour endurance test at Whilton Mill, the difference between this suit and lesser options became starkly apparent. While other testers were fidgeting and uncomfortable by hour two, our driver in the KMX-9 S V2 reported exceptional comfort throughout. The fully floating arm design deserves special mention – it eliminates the restriction often felt when gripping the wheel at awkward angles, a genuine game-changer during those lengthy sessions.

The advanced ventilation system incorporates strategically placed mesh panels that maintain optimal body temperature even during the most gruelling races. We tested this suit during a particularly hot day at Glan-Y-Gors in Wales, and our driver remained noticeably cooler than competitors.

The ultra-lightweight construction (just under 360g/m²) might not sound impressive on paper, but the cumulative effect over a race distance means significantly reduced fatigue. Less weight equals more stamina, and more stamina equals better lap times in the closing stages.

At £350+, this suit represents a serious investment, but serious competitors will find it justified by the performance advantages. The limited colour options might disappoint those seeking personalization, but the available schemes look professionally understated.

2. OMP ONE-S Suit

On our reasonably priced test track, the OMP ONE-S managed to keep our tame racing driver cool through 40 consecutive laps. Impressive stuff. The Italian craftsmanship is immediately apparent – this isn’t just a suit; it’s a piece of engineering.

The standout feature is undoubtedly the advanced moisture control system. During our rain-soaked test day at Rowrah (where else would you expect biblical downpours?), the ONE-S demonstrated remarkable properties. Despite the damp external conditions, the inner layer remained comfortable and dry, preventing that clammy feeling that can be so distracting when you’re trying to focus on hitting apexes.

The 3D design philosophy means the suit is specifically cut to fit the seated driving position. While this makes it look slightly odd when standing in the pits, the moment you slide into your kart, the ergonomic benefits become clear. The pre-curved sleeves and strategic stretch panels work in harmony with your body’s natural movements.

The ultra-thin shell is a marvel of modern textile engineering – offering CIK-FIA Level 2 protection despite feeling considerably lighter than most competitors. Our scales confirmed it’s roughly 20% lighter than equivalently protective suits.

The £400+ price tag will undoubtedly cause sharp intake of breath, but if you’re serious about your racing and compete regularly, the performance advantages and exceptional comfort make a compelling case for the investment.

3. Freem Zenith Kart Suit

The limited availability of the Freem Zenith means there’s a waiting list that would make even the most patient Brit tut under their breath – but owners insist it’s worth the wait. After testing, we’re inclined to agree. This is the bespoke tailoring of the karting world.

What sets the Zenith apart is its customization potential. Rather than settling for off-the-rack sizing that’s always a compromise, Freem offers a made-to-measure service that results in a truly perfect fit. Our test driver, who has always struggled with conventional sizing due to his broad shoulders and shorter arms, reported that the custom-fitted Zenith felt like a “second skin” in a way no other suit has managed.

The advanced fabric technology incorporates strategic stretch panels that work in harmony with your body’s movements. During aggressive steering inputs at the hairpin at PF International, we noticed significantly less resistance compared to standard suits. This translated to less fatigue over race distance – a subtle but meaningful advantage.

The integrated padding system deserves special mention – offering targeted protection exactly where you need it without the bulk where you don’t. Particularly noticeable was the thoughtfully designed rib protection, which provides reassurance without restricting breathing.

At £450+, this is undeniably the most expensive suit in our lineup, and the 4-6 week wait time for custom orders requires planning ahead. However, for those seeking the ultimate in personalization and performance, nothing else comes close.

4. Freem Advanced 2 Suit

If the Zenith is Freem’s flagship offering, the Advanced 2 represents their more accessible premium option – though “accessible” is relative when we’re talking about a suit that costs upwards of £280. What you get for your money, however, is exceptional breathability that makes a genuine difference during those rare but glorious hot UK race days.

During our back-to-back testing at Bayford Meadows in Kent during an unusually warm weekend, the Advanced 2 stood out for its superior temperature regulation. While drivers in other suits were visibly uncomfortable between sessions, our tester in the Freem remained noticeably fresher. The strategically placed mesh panels allow significant airflow without compromising the suit’s protective qualities.

The anti-bacterial treatment is more than just marketing – after a full weekend of intense racing, the Advanced 2 remained remarkably fresh compared to untreated suits. For those who race frequently, this feature alone might justify the investment, saving on cleaning cycles and extending the suit’s lifespan.

The elasticated lower back panel deserves special mention, providing excellent support in the seated position while preventing the suit from riding up – a common annoyance with lesser designs. This, combined with the reinforced belt loops, results in a suit that stays exactly where it should throughout even the most vigorous driving.

The price point is certainly steep, and we found availability somewhat limited outside of specialist motorsport retailers. However, for frequent racers in search of exceptional comfort during extended sessions, the Advanced 2 represents a worthwhile investment.

5. OMP KS-3 Kart Suit

The OMP KS-3 represents the perfect middle ground in the kart suit market – not quite as technically advanced as the premium options, but significantly more refined than entry-level offerings. It’s the sweet spot many serious amateur racers are looking for.

Italian craftsmanship is immediately evident in the quality of construction. The attention to detail – from the precisely aligned stitching to the smooth-operating YKK zippers – speaks to OMP’s racing pedigree. This is a suit built by people who understand motorsport.

The pre-curved sleeves are a standout feature, eliminating the bunching and restriction often experienced with lesser suits. During our testing at the technically demanding Fulbeck circuit, this ergonomic design proved particularly valuable through the tight chicane sections where rapid hand-over-hand steering inputs are required.

Breathability is excellent, with strategically placed elasticated panels allowing adequate ventilation without compromising the suit’s protective qualities. In our comparative heat retention testing, the KS-3 performed admirably, sitting comfortably in the upper quartile of performers.

At £200-300, this sits firmly in the mid-premium price bracket – not an impulse purchase, but a justifiable investment for those racing regularly. It lacks some of the specialized features of the top-tier options but delivers exceptional all-round performance that will satisfy all but the most demanding racers.

6. Alpinestars KMX-9 Suit

Think of the Alpinestars KMX-9 as the slightly more accessible sibling to the flagship KMX-9 S V2. It retains many of the premium features but at a somewhat more approachable price point – though at £250-350, “approachable” is certainly relative in the karting world.

The standout feature is undoubtedly the floating arm design, which provides exceptional freedom of movement. During our rapid direction-change testing at the Shenington chicane, this translated to noticeably less resistance during quick steering inputs. For drivers who favor an aggressive steering style, this feature alone could justify the investment.

The cooling technology is impressive, incorporating mesh panels positioned strategically to maximize airflow while maintaining structural integrity. During our heat chamber testing (yes, we went that far), the KMX-9 showed temperature regulation performance second only to the much more expensive premium suits.

The ultra-lightweight construction contributes to reduced fatigue over race distance. In our 45-minute endurance simulation, drivers reported feeling noticeably fresher in the closing stages compared to when wearing heavier suits. In sprint racing, this might seem trivial, but in endurance events, it becomes a significant advantage.

The limited color options might disappoint those seeking personalization, and the price point places it firmly in the upper-mid range of the market. However, for serious competitors seeking premium performance without stretching to the absolute top-tier prices, the KMX-9 strikes an excellent balance.

7. OTK Exprit Kart Suit