Meet the New Silicone Bifins 2: The 5 Biggest Upgrades

A more adaptable and powerful training fin shaped by athlete experience and feedback from thousands of freedivers.

By Zowie Palliaer

The next generation of Silicone Bifins combines five key upgrades designed to improve fit, comfort, power, and performance in the water. Photo credit © @veragiampietro_ and @kostek_visuals.

Silicone Bifins 2 arrive with a clear brief: improve fit, power and comfort without losing the control that makes our fan-favorite silicone fins so useful for technique. Redesigned from strap to blade, the second generation gives freedivers a more adaptable fit and a firmer, more responsive kick.

The design combines feedback from thousands of freedivers worldwide with the experience of world champion freediver and Molchanovs Co-Founder & CEO, Alexey Molchanov. 

“With Silicone Bifins 2 the goal was simple. To make them better overall and to make them easy to use for training but also to make them more powerful, more comfortable and adjustable.”

The second generation builds on everything freedivers valued in the original, with five meaningful upgrades designed to improve fit, comfort, power, and efficiency. Let’s get into the five biggest changes in Silicone Bifins 2.

Built for freedivers at every level, Silicone Bifins 2 make every training session more comfortable, controlled, and efficient. Photo credit © @veragiampietro_ @content_traveler and @kostek_visuals.

An Adjustable Fit

The adjustable heel strap is the most visible change in Silicone Bifins 2. The original has a fixed fit; the new model uses repositionable pins and three strap positions. The central position matches the standard size, with two steps either side to shorten or lengthen it. 

That range lets freedivers tune the fit around their own feet. The strap can sit snugly without socks, make room for neoprene socks, or accommodate a foot that is narrower or wider than standard. It can also extend the useful size range: an EU 42-43 model, for example, may fit an EU 41 or EU 44 foot with the appropriate adjustment.

The back of the strap is shaped to sit comfortably over the Achilles tendon. For pool sessions, open-water training and courses, that flexibility is a practical upgrade freedivers will notice before they enter the water.

A More Powerful Blade

The blade is longer and wider than the first generation, increasing the surface area available to move water. Its updated geometry is also firmer, creating a more stable and powerful kick with better propulsion in both the pool and open water.

Power was not added simply by making the fin stiffer. The blade remains soft enough for technique-focused training, while the revised geometry gives each kick a clearer response. The performance potential of the concept was already clear in 2021, when Alexey Molchanov dived to 100 meters in the first-generation CORE Silicone Bifins.

Silicone Bifins 2 remain useful across a wide range of experience, from learning an efficient kick to refining one for deeper or longer dives.

Rails That Shape Every Kick

Eight rails, four on the front and four on the back, distribute stiffness across the blade and control how it bends. On Silicone Bifins 2, the reinforcement runs all the way to the tip and becomes more pronounced near the foot pocket and toes. That creates a more rigid, reactive base while allowing the rest of the blade to flex through the kick.

The curvature profile draws directly from the geometry of the PRO Line carbon bifins. It’s a deliberate bridge between technique training and performance equipment: the rails encourage efficient movement and prepare the diver for the response of a higher-performance blade.

“The way we designed our rails is inspired by our PRO model, the one we used to set the world records.”

A Foot Pocket Built for Technique

Dedicated right and left foot pockets support the natural shape of each foot. The interior is true to size, offering a relaxed and comfortable fit. Soft silicone reduces pressure points, while the arch support helps hold the foot in an efficient position.

The open-heel design supports the correct ankle-to-foot angle and allows a full range of motion through the kick. Together, the foot pocket, arch support and heel opening encourage the pointed-toe position needed for efficient finning and make the eventual transition to performance bifins feel more natural.

A New Silicone Formula

The second generation uses a new high-tensile silicone that is hypoallergenic, UV-resistant and designed for use in both pools and the sea. It remains stable in temperatures down to -30 C (-22 F), giving freedivers a durable fin for a wide range of training conditions.

The updated formula is stronger and more rigid, so the blade and foot pocket can be made slightly thinner without losing response. That reduced thickness improves comfort and allows a small reduction in overall weight, even with a larger blade and more substantial rails.

“We changed the silicone formula. It’s now more durable, more rigid and because of that we were able to reduce the thickness.”

Silicone Bifins 2 are designed to stay useful as a freediver's technique develops. Beginners get a comfortable fin that makes good mechanics easier to learn. Experienced freedivers get a dependable tool for technique work, pool volume and open-water sessions without giving up a responsive kick.

That breadth extends the appeal of the original, which became Molchanovs' best-selling product. The adjustable strap solves fit problems the first generation could not, while the blade, rails, foot pocket and silicone formula work together to make each kick more stable, efficient and controlled.

Available in Black, Blue, White and Coral, Silicone Bifins 2 are ready for the sessions where technique is built and the dives where technique is tested. Purchase the new Silicone Bifins 2 at now.