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REPLACEMENT ROTOR RINGS ONLY. INCLUDES NEW INSTALLATION HARDWARE. DOES NOT INCLUDE ALUMINUM HATS. Thunderhill is an authorized dealer for Girodisc products. As one of the largest stocking dealers in the country, we ship most Girodisc products the same or next business day to ensure we meet your delivery deadline. These Girodisc replacement rotor rings are direct replacements for the iron discs on your Girodisc two-piece rotors, and no modifications are necessary. New cap screws and washers are included with these replacement rotors. We do not recommend re-using the old hardware. The replacement rotor rings and hat mount together through a floating mount system which utilizes 8-10 high strength alloy steel drive pins manufactured by Girodisc in the USA to their own specifications and are cadmium plated for corrosion resistance. The alloy drive pins transfer the load from the brake action while maintaining the axial and radial float between the disc rotor and hat. The pins are secured by grade 12 cap screws with hardened washers and mounted with anti-noise spring washers to allow for heat expansion while eliminating the rattle and noise associated with floating rotors. The two-piece Girodisc design allows for rotor ring-only replacement to minimize replacement costs and deliver outstanding performance and cooling. Sold/priced per pair.

REPLACEMENT ROTOR RINGS ONLY. INCLUDES NEW INSTALLATION HARDWARE. DOES NOT INCLUDE ALUMINUM HATS. Thunderhill is an authorized dealer for Girodisc products. As one of the largest stocking dealers in the country, we ship most Girodisc products the same or next business day to ensure we meet your delivery deadline. These Girodisc replacement rotor rings are direct replacements for the iron discs on your Girodisc two-piece rotors, and no modifications are necessary. New cap screws and washers are included with these replacement rotors. We do not recommend re-using the old hardware. The replacement rotor rings and hat mount together through a floating mount system which utilizes 8-10 high strength alloy steel drive pins manufactured by Girodisc in the USA to their own specifications and are cadmium plated for corrosion resistance. The alloy drive pins transfer the load from the brake action while maintaining the axial and radial float between the disc rotor and hat. The pins are secured by grade 12 cap screws with hardened washers and mounted with anti-noise spring washers to allow for heat expansion while eliminating the rattle and noise associated with floating rotors. The two-piece Girodisc design allows for rotor ring-only replacement to minimize replacement costs and deliver outstanding performance and cooling. Sold/priced per pair.

REPLACEMENT ROTOR RINGS ONLY. INCLUDES NEW INSTALLATION HARDWARE. DOES NOT INCLUDE ALUMINUM HATS. Thunderhill is an authorized dealer for Girodisc products. As one of the largest stocking dealers in the country, we ship most Girodisc products the same or next business day to ensure we meet your delivery deadline. These Girodisc replacement rotor rings are direct replacements for the iron discs on your Girodisc two-piece rotors, and no modifications are necessary. New cap screws and washers are included with these replacement rotors. We do not recommend re-using the old hardware. The replacement rotor rings and hat mount together through a floating mount system which utilizes 8-10 high strength alloy steel drive pins manufactured by Girodisc in the USA to their own specifications and are cadmium plated for corrosion resistance. The alloy drive pins transfer the load from the brake action while maintaining the axial and radial float between the disc rotor and hat. The pins are secured by grade 12 cap screws with hardened washers and mounted with anti-noise spring washers to allow for heat expansion while eliminating the rattle and noise associated with floating rotors. The two-piece Girodisc design allows for rotor ring-only replacement to minimize replacement costs and deliver outstanding performance and cooling. Sold/priced per pair.

REPLACEMENT ROTOR RINGS ONLY. INCLUDES NEW INSTALLATION HARDWARE. DOES NOT INCLUDE ALUMINUM HATS. Thunderhill is an authorized dealer for Girodisc products. As one of the largest stocking dealers in the country, we ship most Girodisc products the same or next business day to ensure we meet your delivery deadline. These 380mm Girodisc replacement rotor rings are direct replacements for the iron discs on your Girodisc two-piece rotors, and no modifications are necessary. New cap screws and washers are included with these replacement rotors. We do not recommend re-using the old hardware. These rings will not work with factory center hats. They are designed to work with Girodisc hats only. The replacement rotor rings and hat mount together through a floating mount system which utilizes 8-10 high strength alloy steel drive pins manufactured by Girodisc in the USA to their own specifications and are cadmium plated for corrosion resistance. The alloy drive pins transfer the load from the brake action while maintaining the axial and radial float between the disc rotor and hat. The pins are secured by grade 12 cap screws with hardened washers and mounted with anti-noise spring washers to allow for heat expansion while eliminating the rattle and noise associated with floating rotors. The two-piece Girodisc design allows for rotor ring-only replacement to minimize replacement costs and deliver outstanding performance and cooling. Sold/priced per pair.

REPLACEMENT ROTOR RINGS ONLY. INCLUDES NEW INSTALLATION HARDWARE. DOES NOT INCLUDE ALUMINUM HATS. Thunderhill is an authorized dealer for Girodisc products. As one of the largest stocking dealers in the country, we ship most Girodisc products the same or next business day to ensure we meet your delivery deadline. These 390mm Girodisc replacement rotor rings are direct replacements for the iron discs on your Girodisc two-piece rotors, and no modifications are necessary. New cap screws and washers are included with these replacement rotors. We do not recommend re-using the old hardware. These rings will not work with factory center hats. They are designed to work with Girodisc hats only. The replacement rotor rings and hat mount together through a floating mount system which utilizes 8-10 high strength alloy steel drive pins manufactured by Girodisc in the USA to their own specifications and are cadmium plated for corrosion resistance. The alloy drive pins transfer the load from the brake action while maintaining the axial and radial float between the disc rotor and hat. The pins are secured by grade 12 cap screws with hardened washers and mounted with anti-noise spring washers to allow for heat expansion while eliminating the rattle and noise associated with floating rotors. The two-piece Girodisc design allows for rotor ring-only replacement to minimize replacement costs and deliver outstanding performance and cooling. Sold/priced per pair.

REPLACEMENT ROTOR RINGS ONLY. INCLUDES NEW INSTALLATION HARDWARE. DOES NOT INCLUDE ALUMINUM HATS. Thunderhill is an authorized dealer for Girodisc products. As one of the largest stocking dealers in the country, we ship most Girodisc products the same or next business day to ensure we meet your delivery deadline. These Girodisc replacement rotor rings for the Nissan R35 GT-R are Girodisc's updated variant. If you're not sure these are correct for your Girodisc rotors, please contact us. They the are direct replacements for the iron discs on your Girodisc two-piece rotors, and no modifications are necessary. New cap screws and washers are included with these replacement rotors. We do not recommend re-using the old hardware. These rings will not work with factory center hats. They are designed to work with Girodisc hats only. The replacement rotor rings and hat mount together through a floating mount system which utilizes 8-10 high strength alloy steel drive pins manufactured by Girodisc in the USA to their own specifications and are cadmium plated for corrosion resistance. The alloy drive pins transfer the load from the brake action while maintaining the axial and radial float between the disc rotor and hat. The pins are secured by grade 12 cap screws with hardened washers and mounted with anti-noise spring washers to allow for heat expansion while eliminating the rattle and noise associated with floating rotors. The two-piece Girodisc design allows for rotor ring-only replacement to minimize replacement costs and deliver outstanding performance and cooling. Sold/priced per pair.

Girodisc D1-186 Replacement Rotor Rings (Discs) Girodisc replacement rotor rings are direct replacements for the iron discs on your Girodisc A1-186 two-piece rotors, with no modifications necessary. New cap screws and washers are included with these replacement rotors. We do not recommend re-using the old hardware. (This kit is contains two cast-iron discs and associated hardware. No aluminum center hat.) The replacement rotor rings and hat mount together through a floating mount system which utilizes 8-10 high strength alloy steel drive pins manufactured by Girodisc in the USA and are cadmium plated for corrosion resistance. The alloy drive pins transfer the load from braking while maintaining the axial and radial float between the disc rotor and hat. The pins are secured by grade 12 cap screws with hardened washers and mounted with anti-noise spring washers to allow for heat expansion while eliminating the rattle and noise associated with floating rotors. Rotor ring-only replacement helps to minimize costs and deliver outstanding performance. Sold/priced per pair.

Girodisc D2-186 Replacement Rotor Rings (Discs) Girodisc replacement rotor rings are direct replacements for the iron discs on your Girodisc A2-186 two-piece rear rotors, with no modifications necessary. New cap screws and washers are included with these replacement rotors. We do not recommend re-using the old hardware. (This kit is contains two cast-iron discs and associated hardware. No aluminum center hat.) The replacement rotor rings and hat mount together through a floating mount system which utilizes 8-10 high strength alloy steel drive pins manufactured by Girodisc in the USA and are cadmium plated for corrosion resistance. The alloy drive pins transfer the load from braking while maintaining the axial and radial float between the disc rotor and hat. The pins are secured by grade 12 cap screws with hardened washers and mounted with anti-noise spring washers to allow for heat expansion while eliminating the rattle and noise associated with floating rotors. Rotor ring-only replacement helps to minimize costs and deliver outstanding performance. Sold/priced per pair.

Girodisc Rotor Rings (No Hats) Need new rings for your Girodisc 350mm two-piece rotors? We've got them. Rings come complete with new hardware and full instructions for assembly to your existing Girodisc hats. Price is for a pair of rings and hardware kits. Additional hardware kits are available separately.

FITS: Lamborghini Huracan Super Trofeo ONLY REPLACEMENT ROTOR DISCS ONLY, DOES NOT INCLUDE ALUMINUM HAT. Thunderhill is an Authorized dealer for GiroDisc products and we are one of the largest stocking dealers in the country. We ship most products same or next business day to ensure we meet your delivery deadline. The GiroDisc replacement rotor system is a direct rotor disc replacement for the OEM 2-piece hat and rotor and no modifications are necessary. The rotor and hat mount together through a floating mount system which utilizes 8-10 high strength alloy steel drive pins manufactured by GiroDisc in the USA to our own specifications and are cadmium plated for corrosion resistance. The alloy drive pins transfer the load from the brake action while maintaining the axial and radial float between the disc rotor and hat. The pins are secured by grade 12 cap screws with hardened washers and mounted with anti-noise spring washers to allow for heat expansion while eliminating the rattle and noise associated with floating rotors. The 2-piece GiroDisc design allows for rotor only replacement to minimize replacement costs and deliver outstanding performance and cooling. Sold/Priced per pair.

HJC H10 Carbon Fiber SA2020 Auto Racing Helmet The HJC H10 Carbon Fiber SA2020 helmet is ideal for use in all types of auto racing. From the dusty ovals of Tennessee to the starting line at Pomona, its comfortable fire-resistant, moisture-wicking Comfort-Carbon interior and Advanced Ventilation System keep you cool and comfortable. The HJC H10 Carbon is an affordable alternative to more expensive carbon fiber helmets without sacrificing fit, feel or safety. HJC H10 Carbon Fiber SA2020 Auto Racing Helmet Details: Snell SA2020 approved Weight (Large): 3.2 lbs (1.45 kg) Carbon fiber composite weave shell is extremely light weight Superior fit and comfort using advanced CAD technology ACS (Advanced Channeling System) provides front-to-back airflow flushing heat and humidity up and out Optional shields available: Amber, Dark Smoke, Dark Blue, Black Chrome Optional clear spoiler is available Polycarbonate anti-fog shield with tear-off posts Pre-installed M6 terminals for head and neck restraints Improved front ventilation Double D-ring retention system Additional shields for the HJC H10 Carbon Fiber helmet are available here. HJC H10 Carbon Fiber Sizing Chart: SIZE CENTIMETERS HAT SIZE INCHES XS 54-55 6 3/4 – 6 7/8 21 1/4 – 21 5/8 S5 56-57 7 – 7 1/8 M 58-59 7 1/4 – 7 3/8 22 7/8 – 23 1/4 L 60-61 7 1/2 – 7 5/8 23 5/8 – 24 XL 62-63 7 3/4 – 7 7/8 24 3/8 – 24 3/4 XXL 64-65 8 – 8 1/8 25 1/4 – 25 5/8

Bell RS7-K Karting Pro Helmet FIA8878-2024/K2025 The Bell RS7-K brings HP7-derived design, crisp aerodynamics, and kart-specific safety into a lightweight, track-proven package. With FIA 8878-2024 and Snell K2025 approvals, a clear DSAF visor system, and efficient cooling, it’s built for performance-focused karters who want reliable protection and all-day comfort. FIA 8878-2024 protection with HP7-inspired performance Features - FIA 8878-2024 and Snell K2025 certified for competitive karting - Lightweight composite shell based on Bell’s HP7 profile for stability and airflow - Double Screen Anti-Fog (DSAF) visor with sealing gasket for clear vision - Multi-channel ventilation across chin, crown, and rear exhausts for cooling - Kart-specific, non-fireproof interior with removable cheek pads - Compatible with RS7 accessories like top/chin vents, spoilers, and tear-offs Bell RS7-K Helmet Sizing Chart Bell RS7-K Karting Helmet FAQs: What certifications does the RS7-K carry?The RS7-K is approved to FIA 8878-2024 and Snell K2025 standards for kart racing. Is the interior fireproof?No. The RS7-K is the karting version and uses a non-fireproof liner focused on comfort and durability. How do I choose my size?Measure above the eyebrows and around the widest part of your head. Typical ranges: S (57–58 cm), M (58–59 cm), L (60–61 cm), XL (61–62 cm). If you’re between sizes, consider the tighter fit for racing. Can I use this for car racing?It’s designed for karting. For cars, check your rulebook; most car series require SA/FIA car-racing homologations. Does it accept tear-offs and spoilers?Yes. The RS7 family supports visor tear-offs and optional aero pieces like top/chin vents and spoilers. Ready for fast laps and long sessions, the Bell RS7-K blends proven safety, excellent visibility, and cooling you can feel—so you can focus on driving. Where can I buy authentic Bell kart racing helmets?Right here at Thunder Hill . As an authorized dealer, we carry the full range of Bell kart helmets with fast shipping, expert support, and availability at trackside events across the country. For racers who demand the best in safety and performance, Bell kart racing helmets are the ultimate choice. Explore our extensive collection to find the perfect helmet for your racing needs. Bell Kart Racing Helmets: Bell Racing Helmets are renowned for their exceptional quality and safety features. With a wide range of models to choose from, you can find the perfect Bell Kart Racing Helmet to suit your racing needs. Bell Kart Racing Helmet: Each Bell Racing Helmet is a product of meticulous craftsmanship and cutting-edge technology. When you wear a Bell Racing Helmet, you're choosing a helmet that prioritizes your safety and performance on the track. Bell Race Helmets: Bell Race Helmets come in various styles and designs to cater to different types of motorsports. Whether you're into karting, open-wheel racing, or stock car racing, Bell has race helmets tailored for your specific discipline. Bell Race Helmet: Your Bell Race Helmet is more than just protective gear; it's a crucial part of your racing gear. The aerodynamic design of a Bell Race Helmet helps reduce wind resistance, giving you a competitive edge. Bell Helmet: A Bell Helmet is a symbol of trust in motorsports. Professional racers and amateurs alike rely on the comfort, safety, and durability that Bell Helmets provide during intense racing conditions. Bell Helmets: Bell Helmets have a rich history of innovation and excellence. The extensive range of Bell Helmets ensures that there's a model suitable for every racer, whether you're a seasoned pro or just starting in the sport. Bell Carbon Fiber Helmet: Bell Fiber Helmets combine the lightweight properties of carbon fiber with advanced safety features. These helmets are a top choice for racers seeking the ultimate in protection without sacrificing comfort. Kart Racing Helmet: A Kart Racing helmet is a fundamental piece of safety gear for any racer. Bell's race car helmets are engineered to meet the rigorous demands of motorsports, ensuring you stay safe on the track. Racing Helmet: Your racing helmet is your shield against potential accidents. Bell Racing Helmets are designed to offer superior impact protection while maintaining optimal visibility and ventilation. Racing Helmets: Racing helmets are a racer's most vital piece of equipment. Bell Racing Helmets, with their reputation for quality and safety, are the go-to choice for many professionals and enthusiasts in the racing community. Bell Racing: Bell Racing is synonymous with excellence in the motorsports industry. Their commitment to research, development, and testing has solidified their position as a leader in racing helmet technology. Kart Racing Helmet: When it comes to Kart racing, your helmet is your first line of defense. Bell Kart Racing Helmets are engineered to withstand the rigors of high-speed racing, ensuring your head is protected. Kart Racing Helmets: Kart racing helmets from Bell are designed to provide optimal head protection while maintaining lightweight and aerodynamic qualities, allowing you to perform at your best.

Bell Racing MAG-10 Pro Helmet FIA8859-2024 / SA2025 The Bell MAG-10 is a professional-grade open-face helmet designed for drivers who want maximum comfort, communication flexibility, and uncompromising safety. With dual certification to FIA8859-2024 and Snell SA2025, this helmet delivers advanced protection along with premium fit and ventilation for long stints behind the wheel. Pro-level comfort and performance in an open-face design Dual certification The MAG-10 meets both FIA8859-2024 and Snell SA2025 standards, ensuring it is approved for international competition and long-term use in sanctioned racing series. Lightweight composite shell Engineered with a strong yet lightweight composite shell, this helmet provides superior impact protection while minimizing weight to reduce fatigue in endurance driving. Integrated visor and sun protection The MAG-10 features a dark-tinted adjustable visor to protect against glare and improve visibility in bright conditions, making it ideal for open-cockpit racing and track use. Communication-ready interior Designed with professional drivers in mind, the helmet’s interior is compatible with radio communication systems, making it a perfect choice for endurance and rally teams. BELL RACING MAG-10 PRO SA2025 HELMET SIZE CHART BELL RACING MAG-10 PRO SA2025 HELMET FAQs: What certifications does the MAG-10 carry? The MAG-10 is dual certified to FIA8859-2024 and Snell SA2025 standards, making it legal for most international and domestic racing series. Is this helmet communication-ready? Yes, the MAG-10 is designed with integration points for radio and intercom systems, making it a favorite for endurance and rally applications. Does the MAG-10 provide sun protection? Yes, it comes with an adjustable tinted visor to reduce glare and maintain clear vision in bright conditions. Who is the MAG-10 designed for? This helmet is perfect for professional and amateur racers in open-cockpit series, rally, endurance, and track-day events where communication and comfort are critical. The Bell MAG-10 combines professional-level safety with the comfort and versatility of an open-face design, making it the ultimate helmet for serious racers who demand performance and reliability.

Alpinestars GP Race v2 Boot Cuff Driver Suit The GP Race v2 Suit is a multi-layer suit developed for all-round drivers racing in advanced competitions. Compliant with FIA Standard 8856-2018, the GP Race v2 Suit has an athletic regular fit and has a three-layer construction; one layer of aramidic twill and two layers of aramidic base knit. This assembly offers an increase of 5% in breathability performance, while still maintaining a light weight at 400g/m2. The suit also incorporates knitted stretch panels for maximum comfort on the armholes, lower back and crotch areas, with a larger and longer back panel to really aid driver flexibility and range of movement, while the internal flat seam, fully floating arm and extended shoulders provide even greater levels of driver comfort. Alpinestars GP Race v2 Boot Cuff Driver Suit Protection Certified to the new FIA 8856-2018 homologation standard. Alpinestars fully floating arm construction with stretchable knit fabric ensures minimal material resistance while driving. Sold with laundry bag for convenience and effective material fiber protection. Alpinestars GP Race v2 Boot Cuff Driver Suit Construction Multi-layer lightweight suit incorporating knitted stretchable panels for maximum comfort and excellent breathability. Aramidic knitted stretchable panels on back, waist and crotch for enhanced comfort and ease of movement. Ergonomic collar with soft knitted lining for extended coverage and maximum comfort. 100% Aramidic outer shell fabric for exceptional heat and flame-resistant proprieties. Adjustable collar and belted waist ensure a precise fit. Anatomical arm, leg and torso patterned paneling for an optimum fit in the driving position. Alpinestars exclusive shoulder epaulette construction provides an effective feature for the extraction of the driver in the event of a crash. Alpinestars GP Race v2 Boot Cuff Driver Suit Key Features Ribbed, stretchable wrist and foot cuffs for optimum comfort. Premium YKK double slidered zipper personalized for a versatile and customizable fit. Thigh pockets for convenient, peace-of-mind storage. Regular fit design. Weighs 400 g/m2. Alpinestars GP Race v2 Boot Cuff Driver Suit Size Chart

Alpinestars GP Race v2 Driver Suit The GP Race v2 Suit is a multi-layer Driver Suit developed for all-round drivers racing in advanced competitions. Compliant with the new FIA Standard 8856-2018, the GP Race v2 Suit has an athletic regular fit and has a three-layer construction; one layer of aramidic twill and two layers of aramidic base knit. This assembly offers an increase of 5% in breathability performance, while still maintaining a light weight at 400 g/m2. The suit also incorporates knitted stretch panels for maximum comfort on the armholes, lower back and crotch areas, with a larger and longer back panel to really aid driver flexibility and range of movement, while the internal flat seam, fully floating arm and extended shoulders provide even greater levels of driver comfort. Alpinestars GP Race v2 Driver Suit Protection Certified to the new FIA 8856-2018 homologation standard. Alpinestars fully floating arm construction with stretchable knit fabric ensures minimal material resistance while driving. Includes laundry bag for convenience and effective suit fiber protection. Alpinestars GP Race v2 Driver Suit Construction Multi-layer lightweight suit incorporating knitted stretchable panels for maximum comfort and excellent breathability. Aramidic knitted stretchable panels on back, waist and crotch for enhanced comfort and ease of movement. Ergonomic collar with soft knitted lining for extended coverage and maximum comfort. 100% Aramidic outer shell fabric for exceptional heat and flame-resistant proprieties. Adjustable collar and belted waist ensure a precise fit. Anatomical arm, leg and torso patterned paneling for an optimum fit in the driving position. Alpinestars exclusive shoulder epaulette construction provides for the extraction of the driver in the event of a crash. Alpinestars GP Race v2 Driver Suit Key Features Ribbed, stretchable wrist and foot cuffs for optimum comfort. Premium YKK double slidered zipper for a versatile and customizable fit. Thigh pockets for convenient, peace-of-mind storage. Regular fit design. Weighs 400 g/m2.   Alpinestars GP Race v2 Driver Suit Size Chart

Bell Racing Helmets GTX.3 SA2020 Composite With its refined, aerodynamic design and lightweight carbon composite shell, the Bell Racing Helmets GTX.3 Composite SA2020 helmet provides the best performance and pro features for open wheel, open compartment, karting, formula and dirt track racers. This Bell GTX.3 Composite SA2020 has an integrated shield and dual screen anti-fog (DSAF) visor with rear-facing vents which are ideal for these forms of racing, allowing for air exchange and unobstructed vision without worrying about dust and dirt. Bell Racing GTX.3 Auto Racing Helmet Features Snell SA2020 and FIA 8859-2015 homologation Includes clear SE03 3mm DSAF shield (SV SE03/05 pivot system) with DSAF anti-fog insert Sleek aero styling with integrated wing Front chin bar Gurney ("duckbill") improves high-speed aerodynamic performance Venturi airflow system lets fresh air in, hollow synthetic rubber gasket seal keeps dirt, water and dust out High-strength, lightweight carbon-composite construction using new high-pressure molding system Multi-piece, multi-density high-impact custom bead absorbing liner for low- and high-velocity impact protection Ultra-plush grey Comfort-Max FR® interior fabric wicks away moisture Install integrated drinking tube and radio microphone systems with the integrated face piece channels Multi-density foam interior and contoured cheek pads offer a professional fit Standard-sized eye port M6 terminal hardware and hex wrench for Head and Neck Restraint devices Additional visor shields for the Bell Racing GTX.3 available here.