SIXS Light BT V2 functional underwear for hot days tested

Especially under heavy physical strain or in summer, a familiar problem shows up for many riders: heat builds up under your gear, sweat accumulates, and every movement becomes increasingly exhausting.

At 1000PS we've relied on functional underwear for years in such situations. The universal SIXS 4-Season V2 line has proven itself a reliable companion. But once the thermometer starts climbing toward 30 degrees, a second, airier set can definitely help.

With the brand-new SIXS Light BT V2, the Italians now bring a collection developed specifically for exactly these conditions.

The concept behind SIXS functional underwear seems contradictory at first: how can a material cool while also maintaining a balanced body climate? The answer lies in moisture management and a special material structure.

The so-called Breathable Technology (BT) ensures that sweat is immediately transported away from the skin and can evaporate quickly. This keeps the skin dry, body temperature stable, and prevents overheating. Additionally, the material forms a thin layer of air between the skin and outer clothing that has a temperature-regulating effect. In heat it supports cooling, while in the wind it reduces excessive chilling. Especially in combination with wind while riding, this also weakens the familiar windchill effect.

Main features of Breathable Technology at a glance: - Body temperature regulation: The rapid dissipation of sweat supports natural cooling and keeps the body in the optimal range.

- Prevention of moisture and skin irritation: The skin stays dry, reducing friction and irritation.

- Improved wearing comfort: A fit optimally tailored to the riding position ensures more freedom of movement without bunching. Additionally, more robust fibers are used in heavily stressed areas.

- Reduction of unpleasant odors: Less moisture means less bacterial growth - the SIXS Light BT V2 stays fresh longer.

According to the manufacturer, the Light BT V2 is the lightest and most breathable baselayer collection SIXS has developed so far (40% lighter than the 4-Season line). The clear focus was on motorcycle use at high temperatures. The combination of ultra-lightweight material, high breathability, and targeted ventilation is meant to noticeably relieve the body even under full riding gear.

Particularly interesting is the multi-zone construction, which combines different requirements: where more support is needed, denser material is used. This not only offers additional support while riding but also increases durability - especially if you regularly squeeze into a tight leather suit or protector vest. In areas with high sweat production, on the other hand, the structure becomes more open and breathable.

Color: Black Carbon / Black-Dark Grey Sizes: XS/S, M/L (tested), XL/2XL, 3XL/4XL (an online size finder helps with determination)

The BT TS1L V2 is an ultra-lightweight, highly breathable short-sleeve baselayer specifically developed for use in intense heat, high humidity, and heavy sweating. It's aimed primarily at riders and works optimally under leather suits and protective gear, but can also be used in other sports. The goal is to effectively dissipate body heat and keep the skin dry even under heavy strain.

Color: Black Carbon / Black-Dark Grey Sizes: XS/S, M/L (tested), XL/2XL, 3XL/4XL (an online size finder helps with determination)

The BT PNXL V2 is a long, technical baselayer pant for motorcycle use, specifically developed for intense heat and heavy sweating. It's designed to efficiently dissipate body heat and keep skin dry even during extended use, while sitting stably under a leather suit and protective gear, with reinforcements in friction zones.

Color: Black Carbon / Black-Dark Grey Sizes: Unisize

The BT TBXL is a technical multifunctional neck tube for use in high heat and intense strain, developed with a focus on motorcycle use but also suitable for other sports.

Thanks to its multi-zone construction, it offers targeted ventilation, effective moisture management, and a stable fit. The breathable mouth and nose section, flat seams, and slim, stable structure ensure high wearing comfort. As part of the Light BT V2 line, it's also designed to actively dissipate heat rather than store it.

Once temperatures rise, it quickly becomes clear whether a baselayer really works - or does more harm than good. The Light BT V2 products are a good example of how consistently heat-focused functional underwear performs in practice. Even under intense strain, moisture is continuously transported outward, creating a dry, unrestricted wearing feel. Nothing sticks, nothing distracts - the focus stays on riding. At the same time, fatigue is noticeably reduced.

The smooth surface, reinforced in the right spots, also pays off in daily use: it makes putting on and taking off easier - whether you're peeling out of a tight leather suit or slipping back into a sweaty jacket after a break.

Unlike the 4-Season line, which is designed as an all-round solution, the Light BT V2 clearly focuses on maximum performance at high temperatures. The lower weight and more open structure let more air through - but in return also reduce the insulating effect.

For functional underwear to retain its properties long-term, proper care is essential. 1. The SIXS Light BT V2 should be washed at a maximum of 40°C. Fabric softener should be deliberately avoided, as it can damage the fibers. Tumble dryers and irons also have no place here. 2. Gentle drying in the shade is recommended, ideally laid flat, to preserve the material structure. 3. For optimal care, SIXS offers a special detergent called ResolvWear. This is tailored to technical fibers, works even at low temperatures, and reliably removes odors. Additionally, the typical SIXS scent provides a fresh wearing feel.