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Plastic panels and covers are widely used on modern underbones e.g. Modenas Kriss 2.
MCX Raptor, an underbone from the Philippines.
Honda Winner, an underbone with 150 cc engine displacement.

An underbone is a type of motorcycle that uses structural tube framing with an overlay of plastic or non-structural body panels and contrasts with monocoque or unibody designs where pressed steel serves both as the vehicle's structure and bodywork. Outside Asia, the term underbone is commonly misunderstood to refer to any lightweight motorcycle that uses the construction type, known colloquially as step-throughs, mopeds[citation needed] or scooters (see Scooter (motorcycle)).

An underbone motorcycle may share its fuel tank position and tube framing, along with fitted bodywork and splash guards with a scooter while the wheel dimensions, engine layouts, and power transmission are similar with conventional motorcycles.

Unlike conventional motorcycles, underbones are mostly popular in Asia and Greece. In Indonesia, the fourth most populous country in the world, and the largest country in Southeast Asia, almost half the population have a motorcycle, most of which are underbones and scooters. (120 million in 2018, compared to 16 million cars[1]).

Design

[edit]

The appearance and frame of an underbone are quite different from that of a standard motorcycle, but the powertrain is functionally almost identical. The underbone engine is positioned between the rider's feet but the rear wheel is driven by a regular motorcycle secondary chain drive. Styling considerations only mean that the chain-driven nature of the machine tends to be concealed under sheet-metal covers to a greater extent than that of motorcycles.

Plastic panels and covers are widely used on modern underbones, such as a Suzuki FX125
A Suzuki FX125 with covers removed
An early underbone design: the Honda Super Cub, the most produced motor vehicle ever.

In only one significant respect does the underbone differ from the conventional motorcycle - there is no frame member or fuel tank between the seat base and the headstock. Generally, the fuel tank is located under the seat. The underbone arrangement improves the ease of mounting and dismounting and contributes to the cross-gender appeal of the layout as an around-town shopping and commuter vehicle. The engine displacement of a typical underbone motorcycle is generally between 50 cc and up to about 150 cc, though much larger ones are available. Currently, production underbone model with the largest engine displacement is the SYM VF3i, which is powered by a fuel-injected 183 cc SOHC 4-valve water-cooled engine.[2]

Historically, underbones popularized semi-automatic transmissions and indicator systems. In other respects, the technical sophistication of underbones tended to lag those of larger motorcycles, but nowadays they are increasingly equipped with similar electronic ignition, fuel injection, etc.

Underbones do not have large footrests on the sides (compared to scooters/mopeds), this makes it easier, safer and more comfortable to ride on rough roads or off-road. As the rider can more easily stand up or put both feet on the ground while riding, to shift centre of gravity, smooth out rough roads with knees in half-standing, maintain stability and control. Similar to techniques commonly used in dirt biking or mountain biking.

Underbones may have spoked or alloy wheels that are spindle mounted and usually sized to fit small conventional motorcycle frames. These provide much better road-holding and braking than scooters, though it does make punctures more difficult to repair

Underbones generally features a three- to six-speed sequential gearbox, either with an automatic clutch, usually a centrifugal clutch, or a conventional manual hand clutch. Depending on whether the motorcycle has a manual hand clutch or an automatic centrifugal clutch, determines whether the motorcycle transmission is a semi-automatic (automatic clutch) or a manual transmission. It is then coupled to a sprocket and chain drive to transmit power to the rear wheel. There are some exceptions to this, such as the Yamaha Lexam. Although the similar design of an underbone motorcycle, it has a CVT transmission and therefore has no gears for the rider to select, similar to scooters.

Origins

[edit]
The Heinkel Perle was introduced in 1954, four years before the Honda Super Cub

The underbone concept can be seen in some of the European mopeds of the early 1950s, including the NSU Quickly and the Heinkel Perle.[citation needed] The spine-framed, plastic-faired Honda Super Cub is the most produced motor vehicle of all time.[3][4] Production of the Super Cub began in 1958, surpassing 60 million units in April 2008, and continuing to be made in several countries around the world as of 2012.[5][6][7][8]

Other names and derivations

[edit]

In Malaysia and Singapore this vehicle is commonly known as Kapcai or Kapchai, a slang word derived from Cantonese, being a combination of the word "Cub" from the word Honda Cub and "仔" in Chinese. In Cantonese, "仔" (pronounced "jai", or in pinyin "zai") means "little" (or its derivatives, e.g. "small", "mini", etc.)[citation needed]. Therefore,"kapchai" literally means a "Little Cub". With Honda being a very popular brand in Malaysia, all underbone motorbikes have come to be called "kapchai". In Indonesia, it is called "motor bebek"[9] (literally means "duck bike"). In Greece is known as Papi or Papaki, a slang that also means duck.

A variation on the underbone concept known as the "maxi-scooter"[10] or "touring scooter"[11] is popular in the West. These are much larger than the underbones known to the Asian market and vary in size from the early Honda Helix with 250 cc[12] to the 850 cc Gilera GP800.[13] Many current versions are between 400 cc and 650 cc, including the Honda Silver Wing with 582 cc,[14] the Suzuki Burgman with 400 cc[15] or 638 cc,[16] the Yamaha Majesty 400 with 395 cc,[17] and the Yamaha T-Max 500 with 499 cc.[18]

Underbones of conventional size are popular in Western Europe and marketed alongside conventional scooters. They are sometimes referred to as scooters,[19] despite the design difference between underbones and conventional scooters.

In Southeast Asia Some manual underbone bikes are designed by cover body without side wings, full-length front shock, and sport bike look headlamp. It look more sporty and better performance than the cub underbones. For example, Suzuki Raider R150, Honda Nova series, Suzuki Akira/Stinger, Yamaha MX Speed, Cagiva Stella, and many more. In Indonesia, this type of bike are called "ayago" (ayam jago means rooster)

Storage

[edit]
Yamaha Nouvo's helmet storage compartment.

Underbone motorcycles often come with storage, and this may vary between markets. In Southeast Asia, there is commonly a steel basket provided as there is none under the seat, as this is the placement of the fuel tank. Some underbones have a lockable storage compartment under the seat. Some have a hook in the area between the rider's knees for a shopping bag. Another storage capacity may be provided in a top box, detachable in some cases.

Manufacturers

[edit]

The market for underbone motorcycles is dominated by Japanese manufacturers, though many of them are built in factories elsewhere, including China and Taiwan. In other cases, manufacturers have violated copyright and illegally copied the models of Japanese manufacturers. The Honda Cub, Honda Wave series, and Yamaha Lagenda series are amongst the most copied.

MZ Motorrad currently produces underbone models in Malaysia by their main shareholder, Hong Leong Group which is also the sole distributor of Yamaha motorcycle in Malaysia and Singapore. Mforce Bikes Holdings Sdn Bhd also producing an underbone motorcycle under Benelli Motorcycle.

The major underbone manufacturers are as follows:

Culture

[edit]
Underbones parked in Hanoi

Underbones are very popular in Southeast Asia and Greece. There is a demand for aftermarket and tuner parts. Many enthusiasts modify their underbones either for a show (such as installing small sound systems, neon lights and custom paint jobs) or for performance (like increasing the engine power and fine-tuning the suspension). Riding gear may not even extend to wearing shoes and long pants for safety. Illegal underbone drag racing has become popular in countries such as the Philippines, Malaysia, Thailand, Indonesia and Greece, and poses safety issues for the commuting public as well as the riders themselves, as underbones offer little protection in the event of crashes. The most popular underbone for these purposes is the Honda XRM, Suzuki Raider 150 and the Honda Wave, although similar models from Kawasaki and Yamaha are also frequently used.

In Singapore and Malaysia, it is not uncommon to see old bicycles customized with parts found on an underbone motorcycle, a growing trend popular with the youth.

Racing

[edit]

Underbone motorcycle racing are one of the most popular motorcycle racing class in the Southeastern Asia region, which uses a modified version of road-legal, production-based underbone motorcycle available for purchase in public, mostly manufactured by Yamaha, Honda, and Suzuki. Underbone racing popularity is mostly influenced by their wide variety of racing classes, race track limitations, and fairly cheaper cost of parts and development compared to sport motorcycle classes. Underbone racing class may be further categorized into the engine cycle, engine displacement, engine layout, fuel delivery systems, allowable modifications and restrictions, time brackets (in drag racing), and the rider's skill level. These categories are then regulated by the country's motorcycle racing governing body, from which national racing series may be organized. One of the most popular categories is the 150cc four-stroke fuel-injected class and may have engine power output ranging from 24 to 32 horsepower and can reach up to 180 km/h. Most of the motorcycle competing in this class are Yamaha T-150, Honda RS150R, and Suzuki Raider 150.

Malaysian Cub Prix

Notable underbone road racing series in Southeast Asia countries are Malaysian Cub Prix and Indonesian Oneprix and MotoPrix Series. The highest level for underbone road racing class is held by Asia Road Racing Championship under UB150 class, from which only production underbone motorcycle with a maximum of 150cc engine displacement may compete in this class, hence the name. Only Yamaha and Honda motorcycles compete in this class with teams from various Asian countries.

Underbone racing series in lower divisions in each country may also be organized to encourage new teams and riders to develop and prepare for the national racing series. In Malaysia, the underbone racing series was created in partnership with the government of Malaysia's Ministry of Youth and Culture in 2012 to encourage youth to race in a controlled track environment rather than on the streets.[20] It was designed to have a lower cost of entry than existing underbone series, such as the Malaysian Cub Prix.

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Underbone

View on Grokipedia
from Grokipedia
An underbone is a type of featuring a design with the engine mounted beneath the primary tubular frame component, allowing for easy mounting and a low center of gravity. This configuration distinguishes it from traditional backbone frames, where the engine hangs from the frame, and positions it as an affordable, maneuverable option for urban environments. Originating in the post-World War II era, the underbone design gained prominence through models like the , introduced in 1958, which popularized the format with its simple, reliable and . Honda's adoption of the underbone frame facilitated local production in starting in the 1960s, with assembly beginning in (1967), Malaysia (1969), and (1971), supporting regional and mobility needs. With over 100 million units of the series produced globally by 2017, the bikes earned the local nickname "bebek" (duck) in Indonesia for their agile, waddling ride. Underbones are renowned for their , often exceeding 70 kilometers per liter, rugged durability, and versatility, making them ideal for congested city streets and rural paths in countries like , , and the . Key features include exposed mechanical components for easy , small-displacement engines (typically 50-125cc), and practical additions like rear carriers for . In addition to , they support a vibrant culture of customization and racing across . Modern iterations, such as Honda's Wave and Future series, incorporate and ABS for enhanced performance while retaining the classic design.

Design and Characteristics

Structural Features

Underbones feature a chassis constructed from structural tube framing, often using or tubes to form the main load-bearing structure, which supports the , suspension, and other components. This framing is overlaid with non-structural body panels made of or , providing aesthetic covering without contributing to the vehicle's rigidity, in contrast to designs where the body panels integrate into the frame for strength. The engine is positioned low and slung between the rider's legs, facilitating a step-through frame that eliminates a central backbone running beneath the seat, allowing easy mounting similar to a scooter while maintaining motorcycle-like handling. This placement contributes to the overall compact profile and low center of gravity. Typical underbones employ 17-inch wheels for both front and rear, promoting stability and responsive road handling suitable for urban environments. The drivetrain components, including the chain drive, are often exposed or semi-exposed to prioritize simplicity in maintenance and manufacturing cost-effectiveness. The frame design typically results in a measuring 1,200-1,300 mm, such as the 1,245 mm found on models like the C125, which supports lightweight construction with dry weights ranging from 80-100 kg. This configuration enhances maneuverability and contributes to the category's emphasis on accessibility, with low seat heights aiding riders of varying sizes. Suspension typically consists of a telescopic front fork and twin rear shocks for basic urban handling, while braking uses mechanical drum systems on both wheels or hydraulic disc on the front for modern variants.

Ergonomics and Performance

Underbone motorcycles feature a low seat height, typically ranging from 750 to 800 mm, which facilitates easy mounting and dismounting, making them particularly accessible for shorter riders or those wearing skirts and thereby supporting greater inclusivity in urban settings. This design, enabled by the , contributes to a stable and confidence-building experience for riders navigating congested environments. The upright riding position, with handlebars positioned at chest level, promotes relaxed posture and enhances maneuverability in traffic, allowing riders to maintain visibility and control during frequent stops and starts. In terms of performance, underbones are equipped with single-cylinder, air-cooled, 4-stroke , commonly displacing 110 to 125 cc, which deliver approximately 8 to 12 horsepower for efficient daily . These pair with a 4- or 5-speed , often featuring rotary or sequential shifting mechanisms, alongside semi-automatic variants that simplify operation for beginners. Many models incorporate a system, which engages automatically based on engine speed, eliminating the need for a manual lever and enabling smoother starts without stalling. Operational capabilities emphasize city-friendly traits, with top speeds of 80 to 100 km/h and profiles optimized for quick bursts in stop-and-go rather than sustained cruising. This balance ensures responsive handling in dense urban areas while maintaining reliability for short to medium-distance travel.

History

Origins in Japan

In the aftermath of , grappled with fuel shortages, economic reconstruction, and rising urban populations, necessitating inexpensive and practical transportation options for daily commuting. , founder of Honda Motor Co., addressed this by designing the Super Cub as an affordable, user-friendly tailored to the rebuilding economy, evolving from earlier clip-on engines like the 1952 Cub F to create a standalone vehicle for mass accessibility. The C100 premiered at the 1958 Tokyo Motor Show, introducing the foundational underbone design that would define the category. Key innovations included a lightweight pressed-steel underbone frame for structural simplicity and low weight, a 49 cc air-cooled four-stroke OHV engine delivering reliable power equivalent to larger 125 cc two-strokes, and a step-through with full leg shields inspired by bicycles and scooters for easy mounting and weather protection. These features prioritized practicality, with an automatic and three-speed transmission enabling operation by novices, including women and the elderly. Initial production surged, exceeding 's target of 30,000 units per month to reach 60,000 by late 1958, with over 1,000 units sold on the debut day alone, reflecting immediate demand. The Cub series ultimately achieved over 117 million units sold worldwide as of , establishing the underbone archetype through its enduring emphasis on economy, including claimed fuel efficiency of approximately 60 km per liter under typical conditions.

Expansion in Southeast Asia

The expansion of underbones in Southeast Asia gained momentum in the 1960s through Honda's export and licensing strategies for its Super Cub technology, which facilitated local assembly and production across the region. In Thailand, Honda established Asian Honda in 1964 as a regional hub, beginning local production of Super Cubs in 1965 to meet growing demand. By the early 1970s, similar initiatives took hold in Indonesia via a partnership with the Astra Group in the 1960s, leading to knock-down assembly and the formation of PT Honda Motor in 1971 for full local manufacturing. Super Cub assembly began in the Philippines in 1967 through a licensing agreement with Delta Motor Corporation, with a joint-venture company set up in 1973 and Honda Philippines Inc. established in 1995, marking further localization of Super Cub production. These efforts tied back briefly to the original Japanese design, adapting the efficient, lightweight frame for tropical climates and emerging markets. Underbones rapidly became dominant in key Southeast Asian markets due to their alignment with local needs, particularly in , the , and . In , underbones like those derived from the Super Cub held a substantial through the late , though scooters later gained ground; as of 2020, underbone models accounted for about 48% of two-wheeler sales, though this share has declined to around 32% by 2024 amid growing scooter popularity. The saw underbones emerge as ubiquitous for urban commuting, comprising the largest segment of sales well into the 2020s owing to their versatility in dense traffic. In , the , an underbone variant, has remained a bestseller, dominating the market with its simple mechanics and reliability for daily use. Several factors propelled this growth, including affordable pricing typically ranging from $600 to $2,000 USD, making them accessible to middle- and low-income households, and their nimble design suited to congested city roads with low centers of for easy maneuvering. policies further encouraged by favoring small-displacement engines under 150cc through lower taxes and duties, promoting fuel-efficient in resource-constrained economies. The 1970s oil crises amplified demand, as underbones' high —often exceeding 50 km per liter—offered a cost-effective alternative to amid soaring prices, boosting sales across the region. By the , annual production in countries had surged, with alone outputting over 50,000 units early on and regional totals climbing into the millions as local facilities expanded. In the , underbones evolved from basic utilitarian models, such as the CD50, toward more styled commuters with enhanced aesthetics and features like improved suspension, catering to younger riders while retaining core affordability and efficiency. This shift supported sustained popularity, with regional production exceeding several million units annually by the decade's end, solidifying underbones' role in 's transportation landscape. Into the 2020s, underbone production in continues to exceed 10 million units annually as of 2024, with modern models incorporating and early electric prototypes to meet evolving environmental regulations.

Terminology and Variants

Common Names

The term "underbone" originated as a descriptive label for the motorcycle's frame design, featuring a low-slung main tube positioned beneath the rider's and legs, enabling easy step-through access unlike traditional high diamond frames. This highlights the structural innovation that positions the and frame components "under the bone" (referring to the central element), facilitating accessibility for riders in skirts or carrying loads. In , where underbones dominate urban mobility, regional names often draw from local languages, , or cultural associations. The widespread term "cub" derives directly from Honda's iconic Super Cub model, introduced in , which established the and led to "cub" becoming a generic descriptor for similar lightweight, step-through motorcycles across the region. In and , "bebek" (meaning "") is a common colloquialism, applied as a nod to the perceived sturdiness of these bikes, akin to the resilient nature of ducks in local , rather than any auditory resemblance. Philippine riders frequently use "underbone", reflecting the influence and the bike's low-frame utility. In , variants are sometimes termed "semi-moto," emphasizing their semi-automatic transmissions that blend handling with scooter-like ease. In Western contexts, underbones are occasionally misclassified under broader "step-thru" terminology, originally associated with scooters but adapted to describe the shared low-entry frame. The evolution of these terms traces from perceptions of underbones as "moped-like" hybrids to a formalized "underbone" category by the 1990s, as manufacturers like standardized the design in global export models and industry classifications.

Model Variations

Underbone motorcycles have evolved through various model lines that adapt the core frame design for different user needs, ranging from everyday commuting to more dynamic riding styles. Basic commuter variants emphasize simplicity and durability, exemplified by the , which features a 110 cc engine and was introduced in in the mid-1990s to meet the demands of urban and rural transport in . This model prioritizes reliability through robust construction and low-maintenance components, making it a staple for daily use in traffic-congested areas. Sporty derivations build on the underbone by incorporating aesthetic and functional enhancements to appeal to younger riders. The Yamaha Sniper, with its 150 cc displacement, emerged in the and includes aerodynamic fairings that improve visual appeal and reduce drag, targeting youth demographics seeking a more aggressive look without sacrificing the platform's inherent lightness. These models often feature tuned suspensions and styling cues that differentiate them from utilitarian predecessors, reflecting regional preferences where names like "Exciter" or "Sniper" vary by market but denote similar sport-oriented underbones. Hybrid models introduce crossover elements to the underbone formula, blending on-road efficiency with light off-road capability. The Raider series, available in 125-150 cc configurations, gained popularity in the for its rugged adaptations, such as higher ground clearance and versatile semi-block tire options that enable navigation over unpaved paths while retaining the frame's step-through accessibility. This design evolution allows riders to transition seamlessly between city streets and rural trails, broadening the underbone's utility in diverse terrains. In markets like , adaptations of the underbone frame appear in licensed productions, such as Kawasaki's collaboration with Bajaj on 100 cc models like the , tailored for dense urban environments with compact dimensions and easy maneuverability. By the mid-2020s, derivations have extended to electrified prototypes, including Honda's Cub e concept that hybridizes the Super Cub lineage with electric assistance, featuring a 400W Bosch motor and approximately 40 km range for enhanced efficiency in short-haul commuting as of November 2025. Overall, these variations demonstrate a progression from pure utility-focused designs to specialized versions equipped with upgrades like larger wheels for better stability or disc brakes for improved , catering to evolving rider preferences across global regions.

Manufacturers

Global Brands

Honda remains the dominant global manufacturer of underbones, primarily through its iconic Super Cub series, which has achieved cumulative production exceeding 110 million units since its debut in 1958. The Super Cub's emphasizes exceptional , simple maintenance, and reliability, making it suitable for diverse global markets from urban commuting in to rural applications worldwide. Honda's export strategy has positioned the Super Cub as a staple in over 160 countries, with ongoing production adaptations ensuring its relevance in both developed and emerging economies. Yamaha contributes significantly to the underbone segment with models such as the Crypton and , which prioritize affordability, modern styling, and efficient performance tailored to Asian markets. The Crypton, a 110cc underbone, features a lightweight steel tube frame and practical for daily use, while the lineup, including variants like the Vega Force 115, offers enhanced fuel efficiency and urban maneuverability. These models have gained popularity in countries like and the for their balance of cost-effectiveness and aesthetic appeal, supporting Yamaha's strategy to capture mid-tier market segments. Suzuki's underbone offerings, notably the Raider and Smash lines introduced in the , are renowned for their sporty characteristics and adoption of (FI) technology for improved power delivery and emissions control. The Raider series, such as the R150 Fi, delivers high-performance in the hyper underbone category with a 150cc , appealing to riders seeking speed and agility in compact form. Meanwhile, the Smash Fi models provide versatile leisure options with eco-friendly FI systems, emphasizing solid build quality and under-seat storage for practical commuting. Kawasaki plays a smaller but notable role in the underbone market, leveraging Ninja-inspired designs for mini commuters and forming partnerships to produce 100-125cc models suited for entry-level riders. Examples include the Barako series in select Asian markets, which incorporate durable framing and efficient engines derived from Kawasaki's sportbike heritage, alongside collaborative efforts with local assemblers for customized commuters. These initiatives allow Kawasaki to maintain a niche presence in high-volume underbone regions without dominating the segment. By 2025, commands over 70% market share in key Southeast Asian markets like , the largest underbone hub.

Local Producers

In , , a between Motor Co. and established in the , leads local production of underbone motorcycles, including the Honda Supra (a variant of the Wave series) tailored for the domestic market through knock-down assembly and full at plants in Sunter, Kelapa Gading, and . In the , local assembly operations focus on underbones from Japanese brands, with Philippines producing models like the Smash Fi entirely in-country, including engine assembly, to meet demand for reliable daily transport. Yamaha Motor Philippines handles assembly and distribution of underbones such as the series, emphasizing semi-automatic transmissions for ease of use in congested cities. Corporation manufactures underbones like the Fury 125 at its plant, producing around 18,000 units monthly to support local sales of compact, fuel-efficient bikes. Malaysia features , a government-backed manufacturer formed in 1995 as part of national industrialization efforts following the Proton automotive project, which produces the Kriss series of underbone motorcycles since 1996, incorporating technology transfers for 110cc four-stroke engines suited to local preferences. United Motor Corporation serves as Yamaha's licensee, facilitating assembly and distribution of underbone models like the Y15ZR, which blend sporty design with practicality for Malaysian riders. In , Vietnam, a key local producer, achieved annual output approaching 2.3 million units in 2025, with underbones like the Wave and Winner dominating production and customized for tropical conditions through enhanced corrosion-resistant coatings on frames to combat and . These regional firms reduce costs via local sourcing of components such as and plastics, enabling underbone prices to stay below $1,500 USD while supporting high-volume domestic markets.

Cultural Impact

Transportation Role

Underbones serve as a primary mode of urban commuting in densely populated Asian cities such as , , and , where their compact design allows riders to navigate congested streets efficiently. These motorcycles typically accommodate one or two passengers along with additional cargo, making them ideal for daily errands, family transport, and small-scale commercial activities like market runs or informal delivery services across . For instance, in , underbones are commonly used by riders for tasks, enabling quick trips through heavy traffic to fulfill orders from platforms like GoFood. Their key advantages include superior maneuverability in traffic jams, ease of in limited urban spaces, and for riders, including women, due to the low seat height and that simplifies mounting and dismounting without requiring a full leg swing. This design lowers barriers for riders compared to traditional diamond-frame motorcycles, promoting greater participation in daily mobility among women in regions like the and . Beginners benefit from the straightforward controls and stability at low speeds, contributing to their widespread adoption for short-distance travel. Underbones play a vital socioeconomic role by providing affordable mobility for low-income populations, enabling access to , , and markets in areas with inadequate . In the , approximately 48% of households owned a or as of 2022, underscoring their importance for economic participation among working-class families. In , underbones facilitate the "xe om" system, where drivers use models like the Wave to offer on-demand rides, supporting informal economies and livelihoods for millions in urban centers. This utility is further enhanced by their , which keeps operating costs low for extended daily use.

Racing Scene

Underbone racing has gained significant popularity in the , particularly through events that showcase modified bikes in organized competitions. These events, such as the Motul Nationwide Championships featuring Super Underbone Open SP classes, have been held regularly since the early , attracting enthusiasts who modify 150 cc engines for enhanced performance. In , underbone racing, often referred to as "bebek" racing, emphasizes circuit events and modification contests that blend aesthetics with speed enhancements. Contests like the Modif Contest include categories for bebek sport racing style, where participants showcase customized designs and performance upgrades in competitive formats. Common modifications in underbone racing include engine tuning techniques such as boring out cylinders for increased displacement, exhaust system upgrades for better airflow, and the addition of lightweight components to reduce overall weight and improve acceleration. These alterations are often performed by enthusiast communities, including groups like the 150cc Fusion Underbone Kings of the , which organize rides and share tuning knowledge among members. A notable example is the annual drag racing events in the , such as the No Prep Motorbike Drag Race series, which draw thousands of spectators and participants to venues like those in and , highlighting high-stakes underbone competitions. Underbone racing embodies a form of youth rebellion and DIY culture in the , originating from informal street races in the 1990s that evolved into sanctioned events as organized gained traction to curb illegal activities.

Utility Features

Storage and Practicality

Underbone motorcycles are designed with practical storage solutions to support everyday . A key feature is the under-seat storage compartment, which typically provides 10-20 liters of space for items like helmets, documents, or small groceries; this has been a standard inclusion since 1980s models, exemplified by the Yamaha BOX'N's innovative under-seat box introduced in 1985. Additional utility comes from rear racks designed for light cargo such as groceries or small loads (typically up to 10 kg), side panels suitable for securing bags, and telescopic front forks that ensure stability under load. Practical adaptations further enhance usability, including lockable glove boxes for secure small-item storage and a fuel tank positioned under the seat to maintain a low center of gravity for better balance when carrying goods. In regions like , where underbones are known as "bebek" models, extended rear racks are common to meet the demands of market vendors transporting produce or wares. By 2025, integration of USB ports for phone charging has become common in these models, adding convenience for riders on the go, as seen in models like the Yamaha Finn 125i and KAMAX Cub Pro. These elements collectively enable underbones to serve multi-purpose roles in informal economies, including delivery services and personal errands.

Fuel Efficiency and Maintenance

Underbones are renowned for their exceptional , typically achieving 50-70 km/l (equivalent to 2-3 L/100 km), attributable to their small-displacement engines (usually 100-110 cc) and lightweight construction weighing around 90-110 kg. This design minimizes energy loss and optimizes combustion, making them ideal for daily commuting in densely populated urban areas. Post-2010s advancements, particularly the shift from carbureted to electronic (EFI) systems, have further enhanced efficiency; for instance, models like the Wave RSX with PGM-FI technology deliver up to 67.8-69.5 km/l under standardized testing, representing a 10-15% improvement over comparable carbureted predecessors. The simplicity of underbone facilitates straightforward , enabling owners to perform routine tasks at , such as every 500-1,000 km and cleaning every 3,000-5,000 km, without specialized tools. Parts availability is widespread in due to high production volumes, with basic components like oil filters, spark plugs, and costing $10-50 USD, far lower than those for larger motorcycles. By 2025, EFI-equipped underbones have significantly reduced emissions compared to carbureted models, with studies showing 30-60% lower levels of CO and HC, supporting stricter environmental regulations in countries like and the while maintaining low annual upkeep costs of around $100 USD for routine services including oil changes and tune-ups. Underbone engines demonstrate impressive , often exceeding 50,000 km with regular oil changes every 2,000-3,000 km, thanks to their air-cooled, robust that resists wear in humid tropical climates with minimal breakdowns. This , combined with fuel and expenses totaling under $200 USD annually for average urban use (assuming 10,000 km/year at local prices), underpins their widespread adoption across as an affordable transport solution for millions.

References

  1. https://www.cycleworld.com/lets-talk-about-different-types-motorcycles/
  2. https://www.vikingbags.com/blogs/news/which-is-better-underbone-vs-backbone-motorcycle
  3. https://global.honda/en/Cub/history/stories/vol5/part2.html
  4. https://www.kamaxgroup.com/news/what-is-a-scooter-moped-underbone-or-motorcycle
  5. https://asiaroadracing.com/head-down-elbows-out/
  6. https://hondanews.com/en-US/powersports/releases/release-e888887b6471c0aba407829ba7089f92-2024-honda-super-cub-c125-features-benefits
  7. https://hondanews.eu/eu/lv/cars/media/pressreleases/133910/honda-super-cub-c1258
  8. https://powersports.honda.com/motorcycle/minimoto/super-cub-c125/super-cub-c125-abs
  9. https://powersports.honda.com/motorcycle/minimoto/super-cub-c125
  10. https://desstrongmotors.com/product/honda-supra-gtr150-motorcycle-underbone/
  11. https://www.motor-motorcycle.com/quality-11435423-tin-110-cc-underbone-cub-motorcycle-customized-color-750mm-seat-height
  12. https://premiumbikes.ph/product/honda-wave-alpha-cast/
  13. https://mc.suzuki.com.ph/motorcycles/underbone/
  14. https://www.kamaxgroup.com/news/125cc-2-stroke-underbone-motorcycle-kamax-motorcycle-manufacturer
  15. https://www.jidamotorcycle.com/buy-underbone_motorcycle.html
  16. https://www.zigwheels.my/new-motorcycles/honda/wave125i/standard
  17. https://www.dueksam.com.ph/view_product?model=71&img=/f/j/fj110lx_5_1.jpg
  18. https://strongmotocentrum.com/product/suzuki-raider-j-crossover-automatic/
  19. http://motorcycles.su/moto/hj/haojin-underbone-motorcycle-hj110-11.html
  20. https://cjmotorcycle.en.made-in-china.com/product/cZqGoePYbLaH/China-50cc-110cc-125cc-Lightweight-Underbone-Two-Wheel-Gasoline-Motorcycle.html
  21. https://global.honda/en/Cub/history/stories/vol4/part1.html
  22. https://www.motorcyclespecs.co.za/model/Honda/Honda_C100_Cub_58.html
  23. https://global.honda/en/newsroom/news/2024/c240917eng.html
  24. https://global.honda/en/about/history-digest/75years-history/chapter4/section2_1/
  25. https://global.honda/en/about/history-digest/75years-history/chapter2/section5_1/
  26. https://theicct.org/wp-content/uploads/2022/06/asia-pacificlvsNDC-TIA-23W-market-ASEAN-countries-jun22.pdf
  27. https://www.[statista](/page/Statista).com/statistics/1280000/indonesia-share-of-motorcycle-sales-by-type/
  28. https://www.motorcycleforum.com/threads/whats-stopping-you-from-riding-underbone-or-scooters.244961/
  29. https://www.advrider.com/practical-motorcycling-updated-honda-wave-alpha-launches-in-asia/
  30. https://www.kamaxgroup.com/news/top-6-cub-motorcycles-for-southeast-asia-in-2025
  31. https://www.mordorintelligence.com/industry-reports/indonesia-two-wheeler-market
  32. https://global.honda/en/about/history-digest/75years-history/chapter1/section2/
  33. https://global.honda/en/Cub/history/stories/vol3/p4.html
  34. https://www.grips.ac.jp/vietnam/KOarchives/doc/EB02_IIPF/9EB02_Chapter8.pdf
  35. https://www.aseanbriefing.com/news/motorcycle-production-asean-2024-outlook/
  36. https://global.honda/en/Cub/history/stories/vol1/p3.html
  37. https://www.motorcyclephilippines.com/forum/index.php?threads/what-is-an-underbone.88948/
  38. https://motorbiketourexpert.com/useful-blog/semi-automatic-motorbike
  39. https://www.topgear.com.ph/moto-sapiens/motorcycle-review/review-honda-wave-110r-a00188-20180119
  40. https://www.zigwheels.ph/motorcycle-feature-stories/features-explained-yamaha-sniper-150
  41. https://mc.suzuki.com.ph/motorcycles/underbone/raider-j-crossover/
  42. https://motortrade.com.ph/motorcycles/kawasaki-bajaj-ct100/
  43. https://www.e-scooter.co/honda-cub-e/
  44. https://www.nippon.com/en/japan-topics/g02472/
  45. https://global.honda/en/Cub/history/stories/special-edition/
  46. https://insideracing.com.ph/yamaha-vega-115-basic-but-very-smart/
  47. https://mc.suzuki.com.ph/motorcycles/underbone/raider-r150-fi/
  48. https://mc.suzuki.com.ph/motorcycles/underbone/smash-fi/
  49. https://www.motodeal.com.ph/motorcycles/kawasaki
  50. https://www.industrysourcing.com/article/470022
  51. https://public.dhe.ibm.com/software/solutions/pdfs/07-000824_final.pdf
  52. https://www.facebook.com/SuzukiMotorcyclesPhilippines/posts/suzuki-is-known-for-its-top-quality-products-and-from-its-japanese-manufacturing/728194469332234/
  53. https://www.zigwheels.ph/new-motorcycles/yamaha
  54. https://www.topgear.com.ph/buyers-guide/motorcycles/kawasaki
  55. https://www.iseas.edu.sg/wp-content/uploads/2024/11/TRS26_24.pdf
  56. https://www.rideapart.com/news/682029/yamaha-y15zr-special-edition-malaysia/
  57. https://theinvestor.vn/honda-cements-vietnam-motorbike-market-dominance-with-10-sales-growth-d16333.html
  58. https://www.kamaxgroup.com/news/why-cub-motorcycles-are-the-perfect-fit-for-southeast-asia
  59. https://www.kamaxgroup.com/news/why-underbone-motorcycles-are-suitable-for-commuting
  60. https://www.rideapart.com/news/623368/2023-honda-winner-x-underbone-vietnam/
  61. https://www.kamaxgroup.com/news/unveiling-the-underbone-motorcycle-a-fusion-of-style-and-efficiency
  62. https://dhsprogram.com/pubs/pdf/SR276/SR276.pdf
  63. https://www.kamaxgroup.com/news/why-chinese-commuter-motorcycles-are-ideal-for-urban-transport-in-developing-countries
  64. https://www.facebook.com/InsideRACINGMagazineOfficialPage/posts/super-underbone-open-sp-race-winner-fernando-corteza-iiimotul-super-series-natio/1173386491491146/
  65. https://insideracing.com.ph/ir-news-super-underbone-race-goes-the-way-of-fernando/
  66. https://www.facebook.com/hondamodifcontest/photos/bebek-sport-racing-style-no-peserta-095/494998620699789/
  67. https://www.youtube.com/watch?v=Fsb3ubC4MEo
  68. http://underbonedragracing.weebly.com/engine-performance.html
  69. https://www.facebook.com/groups/772523369791144/posts/2205810313129102/
  70. https://www.facebook.com/groups/150ccfusionunderbonekingsofthephilippines/
  71. https://www.youtube.com/watch?v=RWglqLVNaKo
  72. https://www.facebook.com/quirinoprovinceofficial/posts/%25F0%259D%2597%25A4%25F0%259D%2598%2582%25F0%259D%2597%25B6%25F0%259D%2597%25BF%25F0%259D%2597%25B6%25F0%259D%2597%25BB%25F0%259D%2597%25BC-%25F0%259D%2597%25A0%25F0%259D%2597%25BC%25F0%259D%2598%2581%25F0%259D%2597%25BC%25F0%259D%2597%25BF%25F0%259D%2597%25B6%25F0%2598%2580%25F0%259D%2597%25BA%25F0%259D%2597%25BC-%25F0%259D%259F%25AE%25F0%259D%259F%25AC%25F0%259D%259F%25AE%25F0%259D%259F%25B1-%25F0%259D%2597%25A3%25F0%259D%2597%25BF%25F0%259D%2597%25B2%25F0%259D%2598%2580%25F0%259D%2597%25B2%25F0%259D%2597%25BB%25F0%259D%2598%2581%25F0%259D%2598%2580-%25F0%259D%2597%2597%25F0%259D%2597%25BF%25F0%259D%2597%25AE%25F0%259D%2597%25B4-%25F0%259D%2597%25A5%25F0%259D%2597%25AE%25F0%259D%2597%25B0%25F0%259D%2597%25B2-ready-to-race-bring-your-a-game-and-ex/952785636958308/
  73. https://weekend.sunstar.com.ph/blog/2014/09/05/flashback-friday-philippine-motorsports/
  74. https://www.topgear.com.ph/features/feature-articles/philippines-motorsports-history-a52-20180804
  75. https://japan.webike.net/YAMAHA/BOXN/700/m-spec/
  76. https://www.zigwheels.my/new-motorcycles/honda/wave125i
  77. https://powersports.honda.com/motorcycle/minimoto/navi/navi
  78. https://www.hondaph.com/motor/wave-rsx-disc
  79. https://www.dueksam.com.ph/view_product?model=31&img=/w/a/wave_rsx_drum1.png
  80. https://www.motodeal.com.ph/articles/motorcycle-news-philippines/all-new-2023-honda-wave-rsx-starts-p61-900
  81. https://www.researchgate.net/publication/300814938_Development_of_Fuel_Injector_and_Fuel_Pump_for_a_Fuel_Injection_System_to_Use_in_Small_Motorcycles
  82. https://www.trac.astra.co.id/en/blog/news/underbone-motorcycle-are-famously-durable-and-reliable-here-s-why/749
  83. https://www.alibaba.com/showroom/underbone-motorcycle-parts.html
  84. https://www.atlantis-press.com/article/125965006.pdf
  85. https://www.youtube.com/watch?v=2X7pB5wOY6s
  86. https://aseannow.com/topic/1112798-costs-for-maintenance-paperwork-for-a-cheap-bike/
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