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Castelli  |  SKU: 4526531-010  |  Barcode:

Castelli Estremo Thermal underhelmet - Black

Regular price €45,00
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Castelli Estremo Thermal underhelmet: Protection and Warmth for Winter Cycling

The Castelli Estremo Thermal underhelmet is the ideal solution for those who practice winter cycling and seek uncompromising protection. Made with Polartec® AirCore™ on the front panels, it provides an effective barrier against the wind while maintaining a compact profile under the helmet. The Warmer fabric placed on the back promotes breathability and moisture evacuation, preventing the buildup of humidity. This balance between thermal insulation and moisture management makes it particularly suitable for extended training sessions in cold conditions, where body temperature regulation is essential for comfort and performance.

Thermal Technology and Optimized Ventilation

The Polartec® AirCore™ technology ensures wind protection without adding significant bulk, an essential feature for those wearing the underhelmet beneath a helmet shell. The thickness has been calibrated to provide maximum warmth while maintaining compatibility with any road or mountain bike helmet model. The double-layer structure, with Warmer on the back, creates a thermal management system that allows sweat to evaporate quickly, reducing the risk of sudden cooling during descents or breaks. This configuration is particularly advantageous for those who alternate moments of high effort with phases of active recovery.

Full Coverage and Lasting Comfort

The underhelmet fully covers the ears, protecting the areas most sensitive to cold during winter rides. The full ear coverage significantly reduces body heat loss, a critical element in road cycling where high speeds amplify the wind chill effect. The ergonomic design ensures a close fit without creating pressure points, delivering comfort even during long training sessions. Universal compatibility with standard helmets makes it a versatile choice for any cyclist looking to face the cold season with reliable protection.

Technical Features

  • Front material: Polartec® AirCore™.
  • Rear material: Warmer fabric for breathability.
  • Coverage: Full ear coverage.
  • Thickness: Optimized for helmet compatibility.
  • Protection: Effective wind barrier.
  • Moisture management: Rapid vapor evacuation.
  • Compatibility: Universal with road and MTB helmets.
  • Thermal insulation: Maximum warmth in winter conditions.
  • Weight: Minimal bulk under the helmet.
  • Color: Black.

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Shipping and delivery times

Orders are usually shipped within 24-72 hours (1-3 days) from payment receipt. Some items may have longer shipping times (5-7 days). The specific shipping times are indicated on each product page.

FREE SHIPPING (bikes excluded) from

€ 79.00 Italy
€ 129.00 Europe, Principality of Monaco, and San Marino
€ 249.00 Australia, Canada, Japan, Switzerland, Norway

Shipping costs start from

€ 6.50 STANDARD SHIPPING in Italy with express courier

Shipping times and costs may vary depending on the delivery country, chosen service, and weight.

Shipping with InPost service

€ 5.00 Italy
€ 12.00 France, Benelux, Spain, Portugal, Poland

Bicycle shipping

Shipping costs for all bicycles are fixed as follows.

€ 39.00 Italy
€ 49.00 Europe
€ 69.00 Rest of the world

Non-EU shipping

Local VAT and any customs duties for shipments of goods to customers outside the European Union (non-EU) will be charged to the recipient and requested by the courier at the time of delivery. If the delivery is not made due to refusal to pay the customs duties (local VAT and any applicable tariffs) requested by the importing country, all costs incurred by us for the return of the goods will be deducted from the refund.

In-store pickup

All online-ordered items can be picked up at the All4cycling store in the province of Varese, Via Gianfranco Miglio 2, 21045 Gazzada Schianno (VA).

For further details, we invite you to review the terms and conditions and the privacy policy.

Returns and refunds

  • You can request a return within 60 days of delivery.
  • Start your request from the Returns and Order Cancellations page by entering your order number.
  • Within the first 14 days, you may try the product as necessary to check its features and fit.
  • From day 15 to day 60, the product must be unused, intact and complete with original packaging, labels and accessories.
  • Use beyond what is necessary may result in a reduction of the refund based on the loss in value of the product.
  • The refund is issued, after the returned item has been checked, using the same payment method used for the order.
  • If you paid by cash on delivery, please provide a valid IBAN in the return request notes.
  • Direct exchanges for size, colour or model are not available: return the item and place a new order.
  • For incorrect, damaged or defective products, please contact Customer Service before making the return.

FOR A SAFE RETURN

  • Use suitable packaging to protect the product during transport.
  • Place the product's original packaging inside an outer shipping package.
  • Do not apply adhesive tape, shipping labels or writing directly to the original packaging.
  • Return all accessories, manuals, components and any complimentary items received.
  • Do not remove tags, labels or seals unless necessary to inspect the product.
  • When trying on clothing that you may return, avoid perfume, deodorant or any use that may leave odours or marks.
  • Use a trackable shipping service and keep the shipping receipt until the return has been completed.

For full conditions, exclusions and return procedures, please see our Returns and Refunds Policy.

RETURN SHIPPING COSTS

Italy FREE return at Poste Italiane post offices and collection points, following the instructions provided
Germany & Austria Fixed cost €6.90 with DHL, deducted from the refund
Spain & France Fixed cost €9.90 with DHL, deducted from the refund
Switzerland & Liechtenstein Fixed cost €12.00 with Swiss Post, deducted from the refund
Other Countries Variable cost depending on the carrier selected, fully payable by the customer

The costs shown apply to returns made due to a change of mind. If the product is incorrect, damaged or not as described due to a cause attributable to All4cycling, the necessary return shipping costs will not be charged to the customer.