Wheels

Zipp's 303 S Tubeless Disc Brake wheelset provides today's cyclists the versatility they demand with the speed they crave. Expanding greatly on its heritage of conquering the Spring Classics, this 303 wheelset maintains its ideal-for-every-terrain 45mm rim depth but adds a significantly wider internal width to provide greater performance and ride quality in almost every measurable way. This wheelset is tubeless for disc-brake bikes, allowing the ability to run wide tires at lower pressures for race-ready speed on or off the pavement. The 303 S is among our lightest wheelsets, optimized for top aero performance with a 28mm tire but capable of handling gravel tires up to 50mm wide. - Wide rims optimize tire profile to allow lower tire pressure, especially with tubeless. The result is a larger contact patch for increased grip and confident cornering, descending, and handling in wet conditions. - Lower tire pressures and larger volume provides a compliant ride with fewer vibrations. - Significant watt savings when running larger tires at lower pressure. - Wide, hookless rims create a seamless transition to the tire, reducing drag. - Fastest with 28mm, but fits wide gravel tires as well - New Zipp graphics and cosmetic identity that scream speed

New Sheriff hubs are the ultimate in track racing hubs. They minimize weight with larger cutouts in the flanges, lightened axles, shorter bolts, and slimmer end caps than previous versions. The result is a hubset that weighs a mere 432g, 198g for the front, and 234g for the rear. This makes it one of the lightest track hubsets in the world, a figure even more impressive when you consider that All-City didn't eliminate the usefulness of a fixed / fixed or fixed / free option as most racing hubs do. They feature the finest Japanese manufactured 6902 bearings which roll incredibly fast and smooth while retaining excellent seals for all weather, all-day everyday durability. Front hub specs: - Weight: 198g - Torque Spec: 33nm (25ft lbs.) - Non-Drive Side Center to Flange: 34mm - Drive Side Center to Flange: 34mm - Non-Drive Side Flange Diameter: 62mm - Drive Side Flange Diameter: 62mm Rear hub specs: - Weight: 234g - Torque Spec: 33nm (25ft.lbs.) - Non-Drive Side Center to Flange: 29mm - Drive Side Center to Flange: 29mm - Non-Drive Side Flange Diameter: 62mm - Drive Side Flange Diameter: 62mm

No words needed. Just google "EX 471 Leogang World Cup". Let your muscles play on the uphills and switch to attack mode for the downhills. This is exactly what the DT Swiss Enduro rims are made for. Each rim is a piece of high precision engineering and, thanks to the extremely resistant alloy, the EX 471 can cope with the most demanding trails.

Zipp's 3ZERO MOTO carbon 27.5 and 29 enduro/trail wheelset is inspired by moto to provide riders with the control and durability required for pure trail speed. Already this wheelset and its MOTO Technology are proven with multiple victories in the Enduro World Series with our pioneering partnership with Lapierre Zipp Collective. While other wheel brands limit their focus to traditional box-section rim designs, Zipp engineers-uninhibited by legacy technology-took a different approach. They looked to motorsports as a model. Zipp's Moto Technology's single-wall rim is the optimal approach for an enduro/trail wheelset. The resulting rim provides something we call "ankle compliance." Imagine a runner rounding a sharp turn, the ankle naturally flexing to maintain grip as the runner leans. The 3ZERO rim can locally flex to stay parallel to the ground during cornering, increasing traction like a human ankle adjusts while running. This ability to twist locally allows it to deflect during single bead impacts without the rider getting bounced offline. 3ZERO MOTO helps you take the most direct route, saving seconds when and where they count most. At the center of the 3ZERO MOTO is the ZM2 hubset. This German-engineered hubset features 12 pawls and 132 points of engagement for a quicker response. The hub's improved seal design means better durability on rough terrain. Quarq's TireWiz is an add-on option for 3ZERO to dial in your pressure for an even more compliant ride. Zipp's Speed Line graphics give you the choice of five colors for a wheel with high-performance aesthetics. - Higher impact resistance - Reduced chance of pinch flatting - More traction in rough corners - Smoother ride in rocky terrain - Ability to run lower tire pressure - Reduced rider fatigue - Frustration-free tire installation - Rim is designed for compliance, creating the feel of extra suspension - German-engineered hubset features 12 pawls and 132 points of engagement for quicker response and also has improved durability - Lifetime Warranty

Shimano XT M756 front hub. - Double contact sealing - Super polished bearing races for low friction rolling - Light alloy QR lever and nut - 6-bolt ISO disc mounting surface

Performance Upgrade Made Easy The C38 brings carbon fiber high performance to the real world. It's a versatile all-rounder equally at home crushing gravel washboards and summiting alpine passes. Optimized for use with modern wide tires, providing the right amount of sidewall support to facilitate surefooted handling in all conditions, the C38 wheelset is a great handling, lively climbing, robust all-road performer that also aerodynamically outperforms many deeper, aero-specific rims that cost twice as much. Carbon wheels are a true performance upgrade to any bike, but too often the price tag puts them out of reach. The Rapide C38 shatters that barrier and brings a class-leading Roval carbon rim and DT Swiss reliability together to provide riders with the best performance carbon wheel per dollar.

Upgrade or refresh your Bontrager wheels. Genuine replacement parts Whether you're looking to upgrade to the newest and freshest drivetrain or simply hoping to refresh your trusty wheelset, Trek Genuine Replacement Parts have you covered. - Replacement freehub body - Compatible with SSR and Select wheels - Includes 11mm Allen key adapter for installation

Stan's No Tubes' Presta Removable Valve Core is a replacement valve core for Stan's No Tubes Presta valve stems and Presta valve equipped rim strips.

Product specs: - Size:24", 26" - Width:39mm - Bead width: 39mm - Inner bead width: 30mm - Section height: 27.5mm - Weight (26"): 760g - Sleeved or welded - Hole count: 32, 36

A tubeless-ready disc brake road wheel that mates a carbon fairing and slippery aero profile to a classic aluminum rim. The feel of free speed What do you get when you combine state-of-the-art aerodynamics with the benefits of tubeless-ready? Say hello to Aeolus Comp 5 TLR Disc road wheel. This wheel features a classic aluminum rim and seamlessly attached 50mm carbon fairing for a proven aero profile that's been wind tunnel tested to be incredibly fast. Aeolus Comp 5 TLR Disc is the high-value option for the aero-conscious rider looking to ride fast and stop on a dime. - Rim construction combines lightweight aluminum rim with a bonded carbon fiber fairing - Tubeless Ready (TLR) rims allow for quick transition to a tubeless system - No rider weight restrictions

These rim valves are crucial in upgrading your Tubeless Ready (TLR) Bontrager wheels to the next level of dependability and performance. Key features: - To be used exclusively with Bontrager Tubeless Ready (TLR) wheels - Required for Bontrager's Tubeless Ready (TLR) system setup - Removable valve core for easy sealant fill - Silver MTB valve is compatible with all Bontrager Mountain wheels except: Line XXX, Kovee XXX, and Line Pro 40 - Alloy Road Tubeless Rim Valve is compatible with all Bontrager alloy TLR road wheels

Zipp's 353 NSW Tubeless Disc-brake wheel is the pinnacle of our pursuit of versatility and speed. This wheel fuses Zipp's two most advanced approaches, Sawtooth rim profile and TSE, for an all-encompassing approach to performance. With its undulating 45mm-deep rim shape, the 353 NSW provides speed on every terrain with best-in-class aerodynamic efficiency and crosswind stability. The 353 NSW is Zipp's lightest tubeless wheel yet, making it a fast-puncher ready to fight its way into the breakaway. Zipp's use of hookless (straight side) rims in the 353 NSW is integral to achieving our mission of Making You Faster. With hookless, the transition between the tire and the rim is more seamless and aero. Zipp's hookless rims have more efficient resin distribution, which means lighter wheels. They also are highly durable. Zipp's 353 NSW's Sawtooth rim shape with Hyperfoils optimizes aerodynamic efficiency and crosswind stability. The Sawtooth design also allows the rim to be structurally strong but light. That will help you snap out of corners and maintain that speed no matter the terrain, especially in the steep, punchy stuff. The 353 NSW utilizes Zipp's Total System Efficiency, or TSE, approach to wheel design: overcoming specific barriers to speed: wind resistance, gravity, rolling resistance, and vibration losses. The wheel's 25mm internal width is ideal for running wider tubeless tires at reduced air pressure for a more efficient ride. At the center of the 353 NSW is the Cognition V2 Hubset, re-engineered with an updated Axial Clutch V2 mechanism for quicker engagement and lower friction, as well as improved durability. - Versatile endurance wheel for the modern road bike with tubeless and hookless rim profile - Our lightest tubeless wheel yet, making it a fast-puncher ready to fight - Optimized tire bed for easy tire installation - TSE for greater efficiency and reduced rolling resistance - Sawtooth rim with Hyperfoil nodes and HexFin ABLC dimple pattern for top aero and crosswind-stable performance with an undulating rim depth - Cognition V2 hubset rolls efficiently whether you are pedaling or coasting. Its Axial ClutchV2 technology reduces drag and lowers friction - Ships with 12mm end caps - Center Lock rotor interface. Lockring is included - Zipp graphics applied using Zipp's ImPress direct-print technology - Lifetime warranty

Booster thru-axle hub spacer kits are designed to give your non-Boost front and rear thru-axle hubs the boost they need to fit any Boost-compatible frame or fork.

If you want a lightweight XC wheel that's ready to race, look no further than Kovee Pro 30. It features a lightweight design and 29mm internal width for better traction and cornering performance so you can ride faster and with more confidence. Plus, the Rapid Drive 108 hub provides near instantaneous engagement so you get out exactly what you put in. - OCLV Pro carbon offers an optimized blend of weight, strength, and durability - Rapid Drive 108 hub instantly transfers effort into forward momentum - Tubeless-ready (TLR) rims allow for quick upgrades to tubeless - Boost 110/148 wider hub flanges enhance bracing angle for stiffer wheel - Ultra-durable OCLV Carbon rim with 29mm internal, 36mm external width, 28 hole front/rear - 6 bolt disc, Shimano 10/11 speed, SRAM XD driver available separately - Includes TLR rim strip installed, TLR valve, valve core removal tool - No rider weight limit

The Muc-Off Tubeless Rim tape is made from their proprietary performance material with a pressure-sensitive adhesive to provide just the right amount stretch whilst maintaining durability and strength needed to create a lasting airtight seal. Semi-transparent material makes locating the valve hole easy.

Tannus Armour Tubeless inserts are the result of years of top level multi-cell foam manufacturing mixed with extensive professional riding experience. At the heart of Tannus is the patented Aither Technology; a multi-cell foam compound that forms the structure of the Armour. The inserts are designed to displace small impacts while offering a spring-like rebound for a smooth yet playful ride. - 3% Faster than standard tubeless - Flexible sidewall stabilizing "Wings" for smoother ride quality, with 50% more vibration damping - 20mm of rim protection - Not a sealant sponge – keeps sealant where it belongs - Easy Installation (5 Minutes, No tools required) - 150g - About as much as a standard tube (a little lighter)

Upgrade or refresh your Bontrager wheels. Genuine replacement parts Whether you're looking to upgrade to the newest and freshest drivetrain or simply hoping to refresh your trusty wheelset, Trek Genuine Replacement Parts have you covered. - Replacement freehub body - Compatible with Bontrager Entry-level hubs

Zipp Speed Weaponry Freehub Bodies - Material: Aluminum

Origin-8's Pro Pulsion Rim Strips are made from a super-durable, environmentally friendly PVC material.

After a long climb, the perfect trail lies ahead of your tires: flowy, dusty, varied, endless. Nothing holds you back from entering the All-Mountain thrills with the M 1900 Spline wheels. A rim developed with optimal balance of durability and weight offers efficient climbing characteristics as well as dent resistance on single trails. With experienced wheel building by hand, this wheel is a reliable partner to collect freewheeling moments in the mountains. - Intended use = XC and All-Mountain/Trail - Tubeless ready, 30mm wide and light rim - Straight-pull hubs/spokes built with a 3-cross pattern - Includes Tubeless Valve and Tape, 6-bolt adapter with lockring

The pinnacle of aluminum road wheels. The ceramic OXIC surface coating brings brake performance to rim brakes like it has never be seen before. The rims are wide, asymmetric, and lightweight, making for an outstanding stiffness to weight ratio. If set up tubeless, supreme comfort and grip are added to the athletic character. - OXiC rim surface technology for improved braking performance and wear - Tubeless Ready rim compatible with standard clincher tires - 240 hub with 36t SL ratchet system and ProLock Squorx ProHead spokes built with two-cross lacing - Factory installed tubeless-ready tape - Includes titanium RWS skewer, tubeless valve, 10-speed spacer and Swissstop BXP blue brake pads

Get back on the bike with a genuine replacement wheel. When it's time to tune up your ride, Electra replacement wheels have you covered. PRODUCT DETAILS - Original replacement wheels for Electra bikes - Does not include skewer, reflector, rim strip, valve, or owner's manual - Tire and tube available separately - Wheels shipped as photographed

Ultra-light, bolt-on thru-axles, with a low-profile 6mm head for use on Whisky forks and others. They are also available in some common rear frame sizes. See manufacturer's specifications for fitment questions. - Thread Length: 12mm

Take to the open road with the lightest, most durable, best-handling alloy wheel Roval has ever made - the Alpinist SLX. This is the pinnacle of alloy - a wheel so good it earned the Alpinist name. There’s no room for excess weight whether you’re chasing summits or looking for ride quality. For the climbers, the wheels are stiff enough for high-powered efforts and feature confident handling. The newly engineered shot peen treatment increases fatigue life and with proven DT Swiss 350 hubs and Sapim spokes, the overall weight has been reduced by 30 grams. Because every gram counts. LIGHTWEIGHT X RIDE QUALITY: As the first-ever alloy product to earn the Alpinist name, the Roval Alpinist SLX wheels weigh in at 1,485 grams* thanks to premium alloy and a thoughtful build. Confirming what we’ve all felt: lightweight wheels feel better to ride. *1,485 grams production sample weight. Final weights may vary slightly. TUBELESS COMPATIBLE: There’s no room for excess weight whether you’re chasing summits or looking for ride quality. A Shallow rim depth amplified by tubeless compatibility means you’ll get sublime ride quality with the added efficiency, comfort, and flat protection of tubeless tires. RELIABLE PERFORMANCE: Featuring confident handling for high-powered efforts, the newly engineered shot peen treatment increases fatigue life, while the proven DT Swiss 350 hubs and Sapim spokes enhance overall durability and performance. - Rim: Alpinist Alloy, 6061 Alloy Shot-Pened, 700c, Disc Brake, Tubeless Compatible - Rim Details: 24mm Depth, 23.5mm External Width, 20mm Internal Width - Hub: DT Swiss 350 Straighpull Center Lock, Star Ratchet 36t internals (10 degs), 100x12mm & 142x12mm, Shim. RD. 11SP HG freehub (Convertible freehub) - Bearing Type: DT Swiss Sealed Steel Cartridge Bearings - Spokes: Sapim D-Light Straightpull, Front: Radial/Two-cross (2:1) 21 count, DS: 296mm, NDS: 292mm, Rear: Two-cross (1:1) 24 count, DS: 291mm NDS: 295mm - Nipple: Sapim Secure Lock Double Square Alloy Blk, 2.0 x 18mm, 16cNm - Max Pressure: 130psi - Weight: Wheelset 1,485g, Front 694g, Rear 791g (excluding 15g, tubeless rim tape, and tubeless valve) - Assembly Method: Hand-built - Extras: Roval Tubeless Rim Tape and Tubeless Valve, Spare Spoke & Nipple Kit, Lifetime Warranty, System Weight Limit: 275lbs / 125kg

From the purist gravel racer to the mixed-surface fanatic, Terra CLX II provides a level of weight savings and material confidence that’s unheard of in the all-road or gravel space. This tier of weight-savings translates to rocket-like acceleration off the starting line, nimble performance in the hills, and unleashed efficiency on those loaded-down long-haul excursions. Weighing in at just 1250 grams, the Roval Terra CLX II are the lightest wheels in their class, rivaling pure climbing wheels in terms of weight and out-performing in raw toughness. We were able to get even lighter than before (50 grams lighter) by utilizing Low Flange Disc (LFD) hubs, borrowed from the Alpinist CLX II wheels. What’s being carried forward from the previous generation, is the rim. With its multiple Unbound victories, we we kept what was already class leading, and extended our lead. Because Terra CLX II is a hooked rim, you’re able to ride almost any tire and pressure. Thanks to the 25mm internal width, they work seamlessly with 28-47c tires (up to 80 PSI), giving you options to customize your setup for what’s ahead. Using Roval LFD hubs, still spinning on DT Swiss 180 hub internals, Terra CLX II continues to provide flawless ride quality. The CINC ceramic bearings inside do some serious heavy lifting when it comes to the efficiency of these wheels. Even with laundry list of demands that need to be met for the serious gravel racer, to the all-road explorer—the Roval Terra CLX II checks every box with authority. - Rim: Terra CLX Carbon Clincher, 700c, Disc Brake, Tubeless Compatible - Rim Details: 32mm Depth, 30mm External Width, 25mm Internal Width - ERD 577mm - Hub: Roval Light Hub (LF13/LF14R) Center Lock, DT Swiss 180 Ratchet EXP 36t internals (10 degs), 100x12mm & 142x12mm, Shim. RD. 11SP HG freehub - Bearing Type: DT Swiss SINC Ceramic Bearings - Spokes: DT Swiss Aerolite T-head, Front: Radial/One-cross (2:1) 21 count, DS: 278mm, NDS: 290mm, Rear: One-cross/Two-cross (2:1), DS: 290mm NDS: 288mm - Nipple: DT Swiss Hex Prolock Al 2.0x14mm - Tire Size: 28mm - 47mm - Max Pressure: 28c-32c: 80psi, 33c – 36c: 65psi, 37c- 47c: 60psi - Weight: Wheelset 1,250g, Front 570g, Rear 680g (excludes 15g, tubeless rim tape and tubeless valve) - Assembly Method: Hand built at every step, from rim layup to the last nipple turn. - Extras: Roval Rim Tape, Spare Spoke & Nipple Kit, System Weight Limit: 275lbs/125kg

We designed Teravail tubeless tape for no-hassle installation. Its slight stretch allows the tape to easily conform to your rims. The translucent material shows you exactly where the tape makes contact. It's tacky enough to prevent shifting but easy to pull up if needed, and it won't leave residue on your rims. - Teravail Tubeless Tape comes in a variety of widths to fit almost any rim. - Teravail Tubeless Tape is available in a variety of widths and roll lengths. - Ten-meter length is enough for a single layer on approximately four wheels

The Traverse Alloy rim geometry is optimized for strength, crafted with our most durable alloy, and laced to DT 350 hubs with stout Sapim spokes and Sapim alloy nipples. What does it all add up to? A wheelset that hits harder, holds up longer, and inspires you to go bigger and farther than any other trail wheel out there. ENGINEERED RIM The engineered rim shape emphasizes the durability and strength of alloy; creating our most durable alloy wheel we have ever made. 6013 ALLOY New 6013 alloy material finished with shot peening for impact strength and fatigue strength. OFFSET ADVANTAGE Engineered rim offset enables balanced spoke tension for improved fatigue life to keep you rolling. RIDE QUALITY Ride quality and impact targets derived from our factory enduro team riders. INTERNAL RIM 30mm internal rim width optimizes tire shape for the best traction. ENGINEERED SHAPE Engineered bead shape ensures the bead bends inward for air pressure /tire retention under impact, so you can always finish your ride. WEIGHT 1900g (with valve and tape). SPOKE COUNT F/R 28H Front and Rear HUB DT 350 Star Ratchet HUB ENGAGEMENT 36 Teeth / 10 Degrees INTERNALLY CANTED Internally canted bead shape ensures the bead bends inward for air pressure /tire retention under impact. INTENDED USE Trail, Park, Enduro WEIGHT (29) 1,904g (with valve and tape) WHEEL SIZES 29 (F/R) 27.5 (R) FOR LIFE Lifetime warranty on Roval Wheels when registered within the first 90 days of purchase. 2 YEAR If you damage your Roval product while riding within the first two years of ownership and it's not covered under warranty, we'll still replace or repair. USA Only and wheels must be registered. STRUCTURAL WEIGHT LIMIT (Rider & Cargo) - 125kg / 275lbs

The Traverse Alloy rim geometry is optimized for strength, crafted with our most durable alloy, and laced to DT 350 hubs with stout Sapim spokes and Sapim alloy nipples. What does it all add up to? A wheelset that hits harder, holds up longer, and inspires you to go bigger and farther than any other trail wheel out there. ENGINEERED RIM The engineered rim shape emphasizes the durability and strength of alloy; creating our most durable alloy wheel we have ever made. 6013 ALLOY New 6013 alloy material finished with shot peening for impact strength and fatigue strength. OFFSET ADVANTAGE Engineered rim offset enables balanced spoke tension for improved fatigue life to keep you rolling. RIDE QUALITY Ride quality and impact targets derived from our factory enduro team riders. INTERNAL RIM 30mm internal rim width optimizes tire shape for the best traction. ENGINEERED SHAPE Engineered bead shape ensures the bead bends inward for air pressure /tire retention under impact, so you can always finish your ride. WEIGHT 1900g (with valve and tape). SPOKE COUNT F/R 28H Front and Rear HUB DT 350 Star Ratchet HUB ENGAGEMENT 36 Teeth / 10 Degrees INTERNALLY CANTED Internally canted bead shape ensures the bead bends inward for air pressure /tire retention under impact. INTENDED USE Trail, Park, Enduro WEIGHT (29) 1,904g (with valve and tape) WHEEL SIZES 29 (F/R) 27.5 (R) FOR LIFE Lifetime warranty on Roval Wheels when registered within the first 90 days of purchase. 2 YEAR If you damage your Roval product while riding within the first two years of ownership and it's not covered under warranty, we'll still replace or repair. USA Only and wheels must be registered. STRUCTURAL WEIGHT LIMIT (Rider & Cargo) - 125kg / 275lbs

SMOOTHER IS FASTER Trail riders who prize nimble handling will be blown away by Traverse SL II's category-leading control, strength-to-weight ratio, and pinch-flat resistance. LIGHTER At 1,645 grams, this is our lightest trail wheelset ever. STRONGER Front and Rear Specific Rims with carbon layups optimized for strength and weight boast 15% greater front wheel strength and 25% more rear wheel strength than the previous Traverse SL. CONTROL-BOOSTING VERTICAL COMPLIANCE 21% more vertically compliant than the previous Traverse SL (delivered through Shallow Rim Shape and front/rear specific layup) enables enhanced terrain hugging and bump-force absorbing control. TRACTION MONSTER Carefully engineered rim shape intentionally flexes for improved support and traction to boost confidence and control. TOUGH LIFE, LONG LIFE Engineered rim offset enables balanced spoke tension for improved fatigue life. Lifetime warranty on Roval Wheels when registered within the first 90 days of purchase. SAYONARA PINCH FLATS Optimized "Flat Top" bead profile requires 85% more force to pinch flat compared to a standard round bead, virtually eliminating "snake bites." AIR TIME Thank our genius engineer Chuck Teixeira for inventing the "Roval ThreadBed Valve"; a valve that threads directly into the rim eliminating compression nuts, air loss from rim flex, and makes tire set-up easier, and reduces sealant clogs. INTENDED USE Trail WEIGHT (29) 1,645g 240 EXP (with valve and tape) WHEEL SIZES: 29 2 Year "It Happens" No Fault Crash Replacement - If you damage your Roval product while riding within the first two years of ownership and it's not covered under warranty, we'll still replace or repair. USA Only and wheels must be registered. STRUCTURAL WEIGHT LIMIT (Rider & Cargo) - 125kg / 275lbs

Dependable Independence – Reliability, versatility, and simplicity are united in a hub. The 350 hub is a dependable road mate for every adventure, whether on asphalt or gravel roads. A lightweight axle in combination with a milled hub body ensures a low weight while the proven Ratchet System with 36 teeth guarantees reliable power transmission. The plug-in construction allows maintenance of the freehub system without special tools and conversion to different standards - for maximum versatility. PRODUCT DETAILS: - A DEPENDABLE HUB The freehub Ratchet System makes the 350 the dependable partner for any ride - NO TOOL CONCEPT Plug-in hub construction allows for quick and tool-free maintenance - NEW ENDCAPS The new shape of the end caps facilitates disassembly and thus speeds up handling requiring disassembly - VARIETY The 350 hub is available for all common axle standards and for the various drivetrain systems. TECHNOLOGY: We believe in the art of engineering and strive for sophistication in the product development process. Our guiding idea is to constantly push barriers with our in-house developed technologies. LEGENDARY RELIABILITY: The patented freewheel system, which features high-precision star ratchets, guarantees top performance and reliability. The simultaneous engagement of the ratchet teeth makes the Ratchet System extremely reliable since the loads are distributed equally across a large contact surface.