Shimano Ultegra R8170 C60 Carbon CL Front Disc WheelThe Ultegra R8170 C60 Carbon CL Disc Wheel from Shimano features a 60mm-deep full-carbon rim that's ideal for high-speed and flatter race events. Suited to time trial and triathlon races, this wheel is tubeless ready for fast rolling speeds, low rolling inertia and exceptional grip in all conditions. And it's compatible with Shimano 11 and 12-Speed gear systems and it features a centre lock rotor mount for use with disc brakes.Designed for the highest speed environments and modern tyre widths, the Ultegra C60 front wheel shares its all-carbon rim profile with Dura-Ace but employs a hub that is compatible with both 11 and 12-speed cassettes.For situations where aerodynamics is the priority, the new Ultegra R8170 C60 front wheel features an all-carbon, 21 mm internal, tubeless compatible rim and a super-fast cup and cone bearing hub that is compatible with both 11 and 12-speed cassettes.Centre-Lock Disc Rotor MountThe Centre Lock system makes an easy rotor installation possible with a spline mount and a lock ring. The lock ring mounting system reduces the total working hours by shortening the amount of time of both installation and de-installation. In addition, the secure fixing by the spline mount enhances precision and rigidity while improving braking efficiency.D2 Aerodynamic Rim ProfileAerodynamic performance is affected by wind direction. To create the D2 rim, Shimano engineers considered both frontal and crosswinds, aiming to achieve optimal performance in real-world riding conditions. Extensive prototype testing, in the wind tunnel and on the road, proved that a wide rim shape with a deep tyre bed performs best across a wide range of conditions. At yaw angles ranging from 0 to 15 degrees, the Shimano D2 rim profile reduces air drag better than others aero shape rims. This rim design also boosts lateral wheel stiffness and offers improved vertical compliance for increased control, comfort and durability on the road.Shimano E-Thru Axle SystemThe tool-less type thru-axle skewer system optimizes rigidity and weight balance and enables easy operation with a reliable internal cam mechanism. The 15 mm thru-axle system is 15% stiffer torsionally and 25% stiffer in transverse shear than a traditional 9 mm quick release front axle system. High rigidity is secured while keeping the optimum weight balance. The E-Thru axle hub system minimizes the distortion of suspension while maintaining lightweight for riding around sharp corners at high speed.Features: Series: Ultegra R8100 Series Rim: Carbon Tubeless Ready Type: Clincher 60mm height full Carbon rim Internal Rim Width: 21mm Shared rim profile with R9200 Dura-Ace wheels Improved aerodynamics Axle: 12mm E-THRU Disc Rotor Mount: Centre Lock Weight: 738gA 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Wheels & Tyres from Chain Reaction Cycles, the World's Largest Online Bike Store.
Ready to take on any road cycling challenge, this model is packed with some of the finest Shimano technologies available to bring you an unrivalled riding experience. Precisely customise its feel thanks to its reach adjust technology which allows you to adjust it to suit your hand size, riding style and individual rider preferences. Furthermore, its Servo Wave Action technology delivers fast braking efficiency between your pads and rotor, so you can enjoy more rapid braking power and control. Taking its lightweight and sleek design up a notch, Shimano has also installed an anti-slip lever which gives you superior grip and control in any weather conditions. Smooth and reliable, this is a perfect example for taking your rough road cycling further than ever before across mixed terrain conditions. Technologies: Servo Wave Action: When you pull a Servo Wave brake lever, initial pad travel is fast, so little lever movement is needed to bring the pads into contact with the rotor. The power multiplication factor then increases rapidly at the pad-to-rim contact so more of the lever stroke is used to apply greater braking power with improved control. Reach Adjust: Its brake lever is equipped with a reach adjust mechanism. The distance from handlebar grip to lever can be adjusted to suit any hand size, type of riding and individual rider preferences.
Shimano's Ultegra FC-R8100 crank maintains the same quick, precise front shifting and efficient power transfer that Shimano riders have grown accustomed to, but with even more crank arm length options. Spanning 160 to 175 mm in length, Ultegra cranks now cater to smaller riders, triathletes, and cyclists curious about shorter crank arms. An integral part of Shimano's new 12-Speed road lineup, the FC-R8100 crank builds upon Shimano's legendary front shifting and transmission efficiency. With new refinements for seamless 12-Speed shifting, the Ultegra crank is now offered in lengths from 160 to 175 mm, bringing performance and improved fit for smaller riders, triathletes, and riders with specific biomechanical requirements. Hollowglide Chainring Technology Hollow technology on the outer chainring. The Hollowglide construction ensures high rigidity while its hollow structure cuts down on weight yet maintains strength. This provides better power transfer and quicker and more precise front shifting performance. Hollowtech II Forged Crank Arms A lightweight crankset not only reduces the bike’s weight but decreases rotating mass to aid in acceleration. The challenge is to reduce the weight of the crank without reducing its strength and rigidity. Shimano's advanced forging technology has solved the problem through the HOLLOWTECH crank. Just like high-quality frame tubing, a hollow crank arm can provide amazing strength and rigidity at very lightweight. Optimised Balance of Stiffness, Strength and Weight The concept of Hollowtech II technology is focused on producing a superior crankset that will maximize a rider’s power transfer. The rigidity of the crankset ensures pedalling efficiency while its low weight, a key element of the crankset, aids in cycling longer distances over which the rider needs to pedal more. Naturally, Shimano strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank. The addition of Hollowtech II technology integrates the bottom bracket axle with the right crankarm for more stiffness and weight savings to achieve a high-dimensional balance. Its outboard bottom bracket bearing system provides better weight distribution and more pedalling stability, allowing for more efficient power transfer.
Among the greatest performing Dual Control Levers on the market, Ultegra R8150 Di2 offers 12-speed shifting with refined ergonomics and is exceptionally lightweight. Ultegra R8150 Di2 Dual Control Levers are the ultimate in reliable performance thanks to a Di2 electronic wired gear connection and lightweight rim brakes. Refined ergonomics and advanced materials show the racing pedigree of these levers. Shimano E-Tube E-Tube is Shimano's “service” that uses websites or apps to maximize the enjoyment of riding a bicycle by connecting the riders, the bicycles and Shimano. Shimano's genuine application E-Tube Project for Mobile allows you to customize your bike, update firmware, and maintain it by connecting it wirelessly to your bike. You can also get more detailed bike maintenance by connecting to your bike by wire with E-Tube Project via the Windows V4 application. Shimano DCL Dual Control Lever DCL stands for Dual Control Lever. It has brake and shifting functions in the system and enables easy operation. Ergonomic innovation is as critical to higher standard performance as the added gearing. The shift internals borrows the robustness from Shimano's MTB technology and is so smooth and effortless that one finger shifts front and rear are possible. Indeed, shifting is the ultimate act of Shimano Total Integration and simply has to be experienced to be understood. SLR-EV Caliper Compatible SLR-EV is Shimano's SLR braking technology with a dual symmetric pivot brake caliper. The short-arm brake design employs two bearings and a roller to realize greater efficiency in the pivot area and deliver superior modulation and power for braking. Together with the BC-9000 brake cable, the latest calipers deliver 36% more braking power than Shimano's previous brake model.
Despite its smaller, lighter design, the Dura-Ace FD-R9250 brings the fastest front shifting on the market. The fastest just got faster thanks to the Dura-Ace FD-R9250. Tipping the scales under 100 grams, the new design shifts 45% quicker than Shimano's FD-R9150, already the fastest on the market. And the frontal area of the FD-R9250 is also reduced to decrease aerodynamic drag. Shimano Di2 Electronic Drivetrain Performance Thanks to its lightning-fast, accurate, and reliable shifting performance, Di2 puts riders in complete control and ensures a seamless interface between the cyclist and bike like never before. Creating and continually improving the world's best shifting is a complicated undertaking requiring constant technological advancements. From hardware to software, Shimano Di2 technology is on the cutting edge, striving to deliver the best rider experience possible now and in the future. Shimano E-Tube Compatible E-Tube is Shimano's “service” that uses websites or apps to maximize the enjoyment of riding a bicycle by connecting the riders, the bicycles and Shimano. Shimano's genuine application E-Tube Project for Mobile allows you to customize your bike, update firmware, and maintain it by connecting it wirelessly to your bike. You can also get more detailed bike maintenance by connecting to your bike by wire with E-Tube Project via the Windows V4 application. HYPERGLIDE+ Optimised HYPERGLIDE+ dedicated chain technology delivers greater chain retention, improved shifting efficiency, and smoother transmission over rough terrain. Improved chain retention encourages more aggressive all-terrain riding and relieves chain-issue anxiety. Smoother drivetrain transmission and enhanced shifting performance sharpens riders’ concentration and improves acceleration. Better chain engagement cuts abrasion, reduces maintenance, and lengthens the lifespan of the chain.
Pro-Lite Revo GX Gravel WheelsetThe Revo GX provides the reliability, rolling performance, responsiveness and low weight required for successful gravel racing. Combining the strengths and durability of a MTB wheelset and the rolling prowess of the unique road Revo wheels, this design rolls with race-winning authority over any terrain. Spinning on high-quality Japanese EZO bearings and featuring a tubeless-ready, extra-wide rim, it's prepared for any challenge off-road riding can present.Features: Material: Rim: 6061 Alloy; Hub/Freehub: Alloy; Spokes: Sandvik Stainless Steel; Nipples: Brass Rim Width: 23mm Spoke Type: 2.0 straight, rounded Spoke Lacing: 3-Cross Bearings: Japanese EZO Freehub: Shimano 10, 11 Speed Hub Spacing: Front: 100mm; Rear: 135/142mm Weight: 1.8 kgBuy Pro-Lite Wheels & Tyres from Chain Reaction Cycles, the World's Largest Online Bike Store.
Mavic E-Deemax S 35 Disc MTB WheelsetReady for hitting the trails, this electric mountain bike (E-MTB) wheelset is equipped with two asymmetrical maxtal aluminium rims which offer an excellent balance of strength and durability on the most demanding of terrain conditions. Mavic has also kitted out this model with a Black Shield treatment that protects the rims against impacts and scratches, so they look as awesome as they perform on your ride. Another highlight is its disc brake compatibility, which means that you'll benefit from powerful and consistent braking performance as you conquer your way from trail to trail. Built specifically for electric mountain bike riding, it comes trail-ready with some unique technologies to help you ride smoother and have more fun on the trail.E-MTB Wheelset with Pinch Flat ProtectionMavic's patented Pinch Flat Protection (PFP) technology features rims with a wider contact surface at the top of the sidewall, which significantly reduces the risk of tyre cuts and punctures. The wider 35mm rims allow you to run lower tyre pressure for better traction, and the rims pair perfectly with trail tyres ranging from 2.6 to 3.2 inches. In addition, Mavic's patented Fore technology features a fully sealed upper rim bridge that eliminates the need for rim tape, making it the easiest system for mounting and changing tubeless tyres.ISM Machining and ID360 Double Ratchet SystemISM machining removes material from the rims in strategic areas to minimise weight without compromising strength. Mavic uses 28 straight-pull spokes (same spoke length throughout) for a strong connection between the rim and hub, which has an ultra-reliable Instant Drive 360 (ID360) double ratchet system for quick engagement and acceleration. Set up for disc brakes with Centre Lock rotor compatibility, the Mavic E-Deemax S 35 Disc MTB Wheelset is available for Shimano Micro Spline freewheel bodies and comes with UST tubeless valves, spare spokes and accessories.Features: Rim Material: Asymmetrical S6000 Maxtal Aluminium with SUP welding technology Rim Finish: Black Shield treatment (protects your rim against impacts and scratches) Use: E-MTB Axle: Front: 15x110 Boost; Rear: 12x148 Boost ETRTO: 584x35TC Internal Rim Width: 35mm Tubeless Ready: Yes, UST Tubeless and tubetype, Fore tapeless tubeless technology Freehub: Shimano Micro Spline Rear Axle: 12x148mm Boost thru-axle Front Axle: 15x110mm Boost, convertible to 20x110mm Boost thru-axle with adaptors (available separately) Brake Type: Disc brake Brake Rotor Compatibility: Centre Lock Hub Technology: QRM Auto bearing preload technology, Instant Drive 360 freewheel technology Hub Width: Boost only (Front: 110mm; Rear: 148mm) Spoke Material: Steel Spoke Lacing: Front and rear crossed 3, contactless Spoke Count: Front: 28; Rear: 28 Spoke Shape: Straight-pull, flat, double-butted Nipples Material: Fore Integrated Aluminium ASTM Category 5: Gravity riding focused on the descent Recommended Tyre Sizes: 65mm to 81mm (2.5" to 3.2") Mavic Rider Weight: Mavic recommends that the total weight supported by the wheels doesn't exceed 150kg (bike included) Included: Fore adjustment wrench, 2x replacement spokes with each wheel, Multifunction adjustment wrench (delivered with rear wheel) and UST valve and accessories Single or Pair: Pair Weight: Pair: 2030g (Front: 940g; Rear: 1090g)Technologies: ISM Light Rim Technology: An exclusive Mavic patented concept, ISM involves the machining of the lower bridge of the rim between each spoke hole to create a light and rigid rim without reducing the durability of the rim. UST Tubeless Technology: Universal Standard for Tubeless. Ready to ride tubeless system. The UST concept improves traction, control and comfort whilst reducing inertia and flats. Black Shield Treatment: MTB rim treatment. 2x superior lifetime against rock impacts and scratches. SUP Welding Technology: Soudé Usiné Process. After bending, the rim joint is arc welded. The welded seam is then milled for a smooth finish. Pinch Flat Protection: 20% less risk of puncture with PFP. An E-bike-specific innovation to significantly reduce the risk of tyre cuts and punctures. QRM Auto Bearing Preload Technology: Cartridge bearings are double sealed with C3 internal clearance. Their preload is automatically adjusted to guarantee a perfect spin with no play in the long run. Instant Drive 360 Freewheel Technology: The Instant Drive 360 freewheel system is super light and fast to engage with only 9°. A large contactless rubber seal provides low friction, while a wide array of end caps makes it super versatile.Manufacturer's Part Number: LP1629100 Black 27.5" Micro SplineBuy Mavic Wheels & Tyres from Chain Reaction Cycles, the World's Largest Online Bike Store.
Mavic Crossmax XL Centre Lock MTB WheelsetProviding speed, confidence and control on rugged terrain, this mountain bike (MTB) wheelset features a durable aluminium maxtal rim construction that's ideal for handling all the challenges that the trails have to offer. Mavic has also kitted out each rim with a special Black Shield treatment, which protects against impacts and scratches when the terrain gets tough. In addition, its 30mm wide profile is specifically optimised for running lower tyre pressures, so you can benefit from a smoother ride with superior traction and control. Coming complete with the brand's most user-friendly tubeless system as well as Centre-Lock disc brake compatibility, this wheelset is a great upgrade for riders who want increased protection against flats and dependable braking performance, wherever their next adventure takes them.Tapeless, Tubeless Fore TechnologyThis MTB wheelset's rims are made with Mavic's patented Fore technology, which features a fully sealed upper bridge that eliminates the need for rim tape. That saves 30 grams per wheel and does away with the hassle of using tape to set up tubeless tyres. The rim also has a 30mm internal width, perfect for optimising the performance of any modern trail tyre. It's engineered with a super-strong triangular shape and designed specifically to absorb impacts from the trail. Mavic's Black Shield technology gives them a distinctive finish that protects against scratches and abrasions.Stiffer and Lighter MTB WheelsetMavic uses 24 straight-pull spokes in this trail-ready wheelset to further dial in the sweet spot between lateral stiffness and vertical compliance. The Infinity hubs also feature a stiffer and lighter construction that's enhanced by the ultra-reliable ID360 double ratchet system for fast engagement. This version is set up for Centre-Lock disc mounts and is compatible with Micro Spline. Finally, the Mavic Crossmax XL Disc MTB Wheelset is available in either 27.5” or 29” and ships with UST tubeless valves, spare spokes and accessories.Features: Rim Material: S6000 Aluminum Maxtal, Asymmetrical rim design Finish: Black Shield treatment (protects against impacts and scratches) Spoke Material: Steel Use: MTB Internal Rim Width: 30mm ETRTO: 27.5": 584x30TC; 29": 622x30TC Tubeless Ready: Yes, Fore tapeless tubeless technology Tyre Compatibility: UST Tubeless and Tube type Brake Type: Disc brake, Centre-lock Recommended Tyre Sizes: 60mm to 76mm (2.35" to 3.0") Front Axle: 15x110 Boost thru-axle Rear Axle: 12x148 Boost thru-axle Freewheel: Micro Spline Hub Technologies: Infinity Hubs, Instant Drive 360 freewheel technology Spoke Count: Front and Rear: 24 Spoke Lacing: Front and Rear: Crossed 2, contactless Spoke Shape: Straight pull, flat, double-butted Spoke Nipples: Fore integrated Aluminium ASTM Category 4: Enduro and trail-riding Included: Fore adjustment wrench, 2x replacement spokes with each wheel, multi-function adjustment wrench (delivered with rear wheel), UST valve and accessories Max Rider Weight: 120kg (including bike) Weight: Pair: 27.5": 1830g (Front: 850g; Rear: 980g); 29": 1930g (Front: 900g; Rear: 1030g)Manufacturer's Part Numbers:LP1627100 Black 27.5" Micro Spline (Crossmax XL 27,5 DCL Pr Bst MS*)LP1624100 Black 29" Micro Spline (Crossmax XL 29 DCL Pr Bst MS*)Buy Mavic Wheels & Tyres from Chain Reaction Cycles, the World's Largest Online Bike Store.
Fulcrum Racing 5 Disc Road WheelsetThis wheelset is equipped with a hard-wearing aluminium rim construction, which offers an excellent combination of strength, durability and performance as you clock up the miles on the road. Fulcrum has also kitted out this model with an asymmetric rim design that's engineered to improve rim tension, balancing the forces from your disc brakes and sprocket cassette. Another highlight is its 24 rounded straight-pull stainless steel spokes, which ensure smooth and stable rolling performance as you go the extra distance. Coming complete with sealed cartridge bearings and many of the brand's finest technologies including 2-Way Fit, this is a great choice of upgrade for low rolling resistance, increased grip and greater protection thanks to its tubeless compatible design.Endurance Road Bike WheelsetThe Racing 5 DB wheels are the perfect choice for endurance bikes. The lower aerodynamic resistance and decreased stiffness, achieved with the lower 24mm U-shaped profile, makes them the ideal technical choice for long rides without having to worry about climbing, rain or wind, with a consequent saving in energy and increased comfort.2 Way Fit Ready TechnologyIn this case to the aluminium rim has seen an increase in the inner channel width, up to 20mm from the previous model's 17mm, and the addition of the innovative 2 Way Fit system, to comfortably fit 25-28 mm tyres, both clinchers and tubeless (tubeless tape installed and valves included).Laser-Etched GraphicsThe aesthetics have undergone the same intervention as the Racing 4 DB model, with the updated laser-etched graphics, ensuring the long life of their striking design.Features: Rim Material: Aluminium Use: Road Axle Compatibility: Front: 12x100mm; Rear: 12x142mm Inner Rim Width: 20mm Outer Rim Width: 25mm Rim Width: 24mm Profile Height: Low Tubeless Ready: Yes Tyre Size: 700c Tyre Type: 2-Way Fit Ready (Clincher/Tubeless Ready) Brake Compatibility: Disc brake, AFS Spokes Material: Stainless Steel Spokes Profile Technology: Rounded, straight pull Front Wheel Spokes: 24 (Left: 16; Right: 8) Rear Wheel Spokes: 24 (Left: 8; Right: 16) Nipples Material: Aluminium Hubs: Aluminium, Aluminium flanges Bearings: Sealed cartridge bearings, adjustable Freehub Compatibility: Multiple options available to select Finish: Lasered + Stickers Max System Weight Limit: 120kg Single or Pair: Pair Weight: 1660gTechnologies: Anti-Rotation System: This new system raises the concept of spoking to a new level of performance for road bike and triathlon wheels ( and MTB too). The Fulcrum engineers have redesigned the spokes and the hub housings to create a solid and unmoveable whole. The result is that the spokes will never lose their initial tension, thus keeping the wheel perfectly reactive and centred. The spokes will remain in the position that has been studied in the wind tunnel tests to ensure the best aerodynamic penetration possible. Fulcrum Identification Card (F.I.C.) 100% Handmade Quality: Right from its inception Fulcrum has been marked by a feature that continues to this day: that is to design, prototype and industrialise all the wheels characterised by the red “F”. Indeed these take shape inside of the R&D, the leading-edge department that represents the beating heart of the Italian company. Every single component of the wheel, the materials chosen and the technologies applied are the tangible result of the effort that Fulcrum makes every day to give you maximum performance and reliability. AFS Axle System: The Axial Fixing System is the solution developed by Fulcrum to fix the disc brake to the hub. The constraint granted by the butt area of the release mechanism, greater than in familiar standard ones, makes it possible to obtain greater structural rigidity and therefore more precise and powerful braking. Asymmetric Rim: The asymmetry is designed to improve rim tension, balancing the forces from brakes and sprocket cassette. 2-Way Fit Ready: This procedure transforms Racing 5 DB wheels (designed to be used with a clincher tyre and inner tube) into tubeless ready wheels (i.e. with a Tubeless Easy tyre, no inner tube and compulsory use of a sealant liquid). Use of tubeless and tubeless ready tyres is forbidden on 2-way Fit Ready rims without official Fulcrum 2-way Fit Ready adhesive tape. This model comes with tubeless type installed and valves included. Manufacturer's Part Numbers: FULCWF3970AP8A110 Black 700c FULCWF3970AP1A110 Black 700c FULCWF3970AP5A110 Black 700cBuy Fulcrum Wheels & Tyres from Chain Reaction Cycles, the World's Largest Online Bike Store.
High performance Ultegra Wireless hydraulic Servo Wave disc brake Di2 STI's give you control, modulation and power with minimal effort in all riding conditions Wireless connectivity to the front and rear derailleurs for effortless trouble free gear shifts With Di2 technology shifting is easy and precise - just a light touch, as soft as a mouse click, is sufficient for the front or rear derailleur to instantaneously select the correct gear Full and semi synchronized shifting programable, Synchro shift compatible meaning a single shifter can control both front and rear shifting which can be fully custom tuned to your riding preferences. Semi synchronized shifting means when a front shift is made the rear mech will automatically correct to the appropriate ratio Simply pressing tactile buttons allows effortless and comfortable shifting even when your hands are cold Drop bar STI with shift buttons located in a near identical place to the positions you'd assume shifting using a mechanical Shimano STI Hydraulic brake lever with Servo Wave provides excellent stopping power with less effort especially from the hood position Hydraulic reservoir tank provides pad to rotor clearance auto-adjust maintaining braking performance during pad wear Finely tuneable reach adjusters for the levers enable custom fitment for all hands Levers use CR1632 batteries which last for approximately 1.5-2 years
The HollowTech II 12-speed Ultegra chainset offers an ideal balance of light weight and stiffness, making it the perfect choice for both enthusiast and competitive riders HollowGlide hollow outer chainring gives vast improvements in rigidity by virtually removing outer chainring flex and hugely improves shift performance, even under high load The chainring teeth have been developed to work in conjunction with 12-speed HG chains for increased contact to provide greater efficiency and improved power transfer Industry leading HollowTech II cold forged 4 arm hollow cranks have been evolved for maximum rigidity while reducing weight Wide gear pitch spacing increases clearance between chain and leading teeth to provide compatibility to frames with O.L.D. 135 / 142 mm A wide range of chainring options and crank arm lengths are available to meet the needs of all riders and racing disciplines HollowTech II integrated bottom bracket uses a wider bearing placement and larger axle diameter for increased stiffness and efficiency HollowTech II integrated bottom bracket seal design has minimal bearing interface ensuring smooth rolling and increased durability(sold separately)
The HollowTech II 12-speed Ultegra chainset offers an ideal balance of light weight and stiffness, making it the perfect choice for both enthusiast and competitive riders HollowGlide hollow outer chainring gives vast improvements in rigidity by virtually removing outer chainring flex and hugely improves shift performance, even under high load The chainring teeth have been developed to work in conjunction with 12-speed HG chains for increased contact to provide greater efficiency and improved power transfer Industry leading HollowTech II cold forged 4 arm hollow cranks have been evolved for maximum rigidity while reducing weight Wide gear pitch spacing increases clearance between chain and leading teeth to provide compatibility to frames with O.L.D. 135 / 142 mm A wide range of chainring options and crank arm lengths are available to meet the needs of all riders and racing disciplines HollowTech II integrated bottom bracket uses a wider bearing placement and larger axle diameter for increased stiffness and efficiency HollowTech II integrated bottom bracket seal design has minimal bearing interface ensuring smooth rolling and increased durability(sold separately)