The Tour de France has always been a whirlwind of new releases, which to some extent serve to drown each other out. The opening prologue TT was full of strange helmets, and the first few stages were no different.

Riders from Ineos Grenadiers, Bahrain Victorious, Trek Segafredo, and B&B Hotels-KTM have new head protection on their heads. Some have just been released, others are still unofficial. Here is what we know so far.

The as yet unreleased Kask helmet was spotted on the heads of Geraint Thomas, Filippo Ganna, and others. The shape appears to be a mix of the Italian brand's current Protone and Wasabi models.

Taking many design cues from Protone, a new version of this model was recently unveiled, albeit with minor changes from the original. Whatever this is, it has a larger vent than both the Utopia and Wasabi models, so no one knows for the moment whether this will be the new model or a replacement.

The helmet has 12 vents in roughly the same arrangement as the Proton, with the same fore/aft setup, and appears to have left the top of the head smooth for better airflow when the head is angled low in the aero position. In general, the model seems to be an all-rounder model, not one that can handle either the muggy alpine air of mid-summer or the high-speed airflow of a flat stage.

The front vents on either side of the main appear to be partially filled with matte plastic. Is this an insert or simply a design note to tie in with the horseradish, which features a matte shell and more angular details?

The cradle appears to be Kask standard, and the WG11 sticker appears to mirror that of the Protone and other models in that the helmet at least passes additional rotational impact testing, although there is no rotating internal cradle like the MIPS.

Many bike brands have subsidiaries that produce components and clothing. Bontrager provides this function for Trek, and it is noteworthy in itself that the new helmet is branded under the latter rather than the former. It is simply possible that the helmets are "unbranded" with the exception of the team's title sponsor, but in any case, Trek-Segafredo riders are wearing the new head protection.

Taking Bontrager helmets as a starting point, the top-end models for both road and MTB feature WaveCel technology, an in-house technology designed to improve helmet safety and protect against rotational impacts. This new helmet does not include this obvious feature, which may further indicate that it is not a Bontrager model.

It does, however, feature six prominent main panels running almost the entire length of the head, bisected and connected across the top of the head by what appears to be a carbon fiber T-shaped structure.

Little more is known about the helmet, but at least visually, the clean lines and sharp angles make it very attractive.

"How many vents are enough?" 23 would be enough, or so Rudy Project thinks with the new EGOS helmet. It's an all-around road helmet, but it's definitely more about ventilation than aerodynamics.

"Designed to cut through the air and slide in," says the press release, meaning that it is aerodynamically optimized while at the same time being breathable enough to be comfortable in most situations.

The 23 vents are complemented by dual-density shell protection, which also contributes to weight savings, and magnetic fidlock buckles for easy one-handed attachment and removal. To further enhance ventilation, the forehead pad, which is usually a single band on many helmets, is grooved in this case to allow air to be drawn in from under the helmet's brow as well.

The Rudy Project EGOS weighs 250 grams in size M, making it one of the top-of-the-line road bike helmets, but at €209.90, we would expect nothing less.

"The lightest aerodynamic MIPS helmet" is a bold claim, but it is lighter than all the helmets on our best helmets list except the Abus Airbreaker, so even without a definition of "aerodynamic," it is well worth It appears to be worth it.

The Bolle Avio MIPS weighs in at 234g and is light as a feather thanks to the MIPS Air pads. It has more vents than is customary for a fully aerodynamic helmet, which shows how lightweight it is.

Five main vents cover the cooling, with the central one extending nearly to the rear of the helmet. Four thin vents located on the rear diffuser are intended to allow hot air to escape again through the venturi effect.

Available in three colors, including the B&B Hotels-KTM livery, for £235.00, but currently only in size M.