Underbone Motorcycles are translated by people as for ultra super hyper mega fast motorcycles that can actually teleport the rider from one stop to another in no time.

Underbone Motorcycles have different names all across the Asian subcontinent. They are known as “Kap Cai” in Malaysia/ Singapore, “Motor babek” in Indonesia, and “Papi or Papaki” in Greece.

This category of motorcycles is considered a hybrid of mopeds and scooters. It is a type of motorcycle which uses a tubal framing structure with an overlying body of plastic or pressed steel.

Let’s discover more about the underbone motorcycles in this article.

Advantages of Underbone Motorcycles

Underbone Motorcycles are quite popular due to their lightweight framework and fuel efficiency.

They are also low in cost range which makes them easily affordable to a large fraction of the population.

Its small size makes it easy for it to move between large vehicles and avoid traffic jams.

Common Use

Underbone Motorcycles are most common in East Asian and southeast Asian countries. They are extensively used in Indonesia, India, Thailand, Vietnam, Cambodia, Laos, the Philippines, Taiwan, and many other Asian countries.

Apart from the Asian subcontinent, underbones are also popular in Greece and are considered a major milestone by those who buy them.

Underbones have replaced the tasks of delivery trucks and commercial cars in many countries. These include ice cream vans, mail delivery vans, and even taxis.

The sole reason behind this innovation is that motorcycles can easily cut through the jams and lanes, and provide speedy delivery to the doorstep, which conventional vans cannot do.


The outer look and framework of the underbone motorcycle are different but the functional working is the same as the standard motorcycles.

The biggest difference lies in the position of fuel tanks. In standard motorcycles, fuel tanks are located in front of the seat, giving a T-shaped motorcycle.

In underbones, it is located under the seat. This change makes the mounting and dismounting of the bike easier and more user-friendly for both genders.

The main body of these bikes is made with one large-diameter tubular component, mostly made of pressed steel.

It contributes to the lightweight of the motorcycles. This pattern is known as “step-through” in the western world, where underbones are less popular.

The engine drive of an underbone motorcycle ranges from 50 cc to 150 cc. However, engines with greater capacity are also available. The currently available model with the greatest capacity is SYM VF3i with a 180 cc fuel injector and a 4-valve water cool engine.

Other than the above-mentioned points, rear wheels, chain drives, and engine positioning are the same as a standard motorcycle.


One captivating feature of these motorcycles that attracts customers is the storage box. Just like everyone is a fan of clothes with pockets, similarly, motorcycles with storage baskets have a magnetic appeal for everyone.

These storage boxes are either located under the seat like in Honda Wave, Modenas X-cite, and the Yamaha Nouvo, with a secure lockable feature, or inside of the handle, where steel baskets or hooks are attached to hang bags.

Some also come with a detachable storage compartment. These features have a magnetic appeal for users to include them in their “must-haves” list.

Difference between Underbone and Backbone Motorcycles

A backbone motorcycle, just as the name indicates, has a framework that is quite similar to the human spine. The main function of the human spine is to hold all the body parts together without disturbing the balance, the same goes here.

This spine-like body holds all the parts of the bike together, especially the engine. The engine is bolted behind the seat. This type of bike is more economical because of the less amount of material used in manufacturing.

Where the underbone motorcycles gave us a broader view with a large usage space and multiple passenger capacity, backbone motorcycles do not. They are more of a single-person type of bike with less space.

The most famous Backbone Motorcycles include Honda CB92 Benly & Honda Hornet.

What Are the Best Underbone Motorcycles?

Some most popular underbone motorcycle models are Honda Wave 125i, Yamaha Spark 135i, and now more trending since 2007,  the Japanese version of the Honda Super Cub.

However, the King of Underbone motorcycles is Suzuki Raider 160 Fi. It dominated the Super Series Nationwide Championship for two years back to back and won many titles due to its incredible features.

Is a Scooter an Underbone?

In most parts of Asia, scooters are considered the same as underbones, whereas this is not the case. The build and even the engine positioning is entirely different from each other.

In a scooter, the engine is placed near the rear wheel which is not the case with underbone motorcycles and also the wheel size is different. However, the biggest difference lies in the automation of the vehicle.

Underbone motorcycles use semi-automated gearboxes whereas scooters use CVT transmission to start and operate. Hence, totally different from each other.


Write A Comment