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【2024】12 Popular Bosozoku Motorcycles! Kyusha-kai & Bosozoku | Custom Photo Collection
History and Origins of Bosozoku and Kyusha-kai Motorcycles
Before introducing the parts that make up Bosozoku and Kyusha-kai motorcycles, and popular motorcycle models as bases for them, let's briefly review the history and origins of Bosozoku and Kyusha-kai, as well as modifications and Bosozoku bikes.
What are Bosozoku? Also, an explanation of their origins
Bosozoku are groups that ride custom motorcycles with parts like rocket cowls, three-tier seats, and straight pipes, driving in groups through urban areas.
The origins of Bosozoku are said to be the "Kaminari-zoku" (Thunder Tribe) who appeared in Japan in the 1960s, riding motorcycles with modified mufflers that produced loud noises.
The Kaminari-zoku, who mostly rode alone, began riding in groups in the 1970s and came to be known as Bosozoku. In addition to making loud noises, they also began to emphasize their appearance with large cowls and three-tier seats.
Bosozoku are generally antisocial groups that often ride motorcycles without helmets, wearing special uniforms called "tokkofuku," and repeatedly violate traffic laws, such as running red lights and ignoring stop signs.
What are Kyusha-kai? Also, an explanation of their origins
Kyusha-kai are groups of adults who love vintage motorcycles (kyusha) that were sold in the 1970s and 1980s.
While Bosozoku are almost exclusively made up of teenagers and people in their early twenties, Kyusha-kai consist of people of a wide range of ages, from teenagers to their sixties.
Due to stricter laws and increased police crackdowns, the number of Bosozoku who repeatedly committed violations drastically decreased in the 1990s. However, they transformed into Kyusha-kai, who ride motorcycles in a Bosozoku-like style but adhere to the law.
Unlike Bosozoku, who do not wear helmets and repeatedly violate traffic laws such as running red lights, Kyusha-kai wear helmets and abide by traffic laws, which distinguishes them from Bosozoku.
About Bosozoku bikes
A "Bosozoku bike" refers to a modified motorcycle, typically favored by Bosozoku.
These modified bikes often feature rocket cowls, high three-tier seats with backrests, and custom mufflers that produce loud exhaust notes. Many Bosozoku bikes also have flashy paint schemes.
About customization
Motorcycle customization involves changing parts like mufflers and handlebars to suit one's preferences.
There are various reasons for customization, such as making the bike faster or changing its appearance. However, for Bosozoku and Kyusha-kai, customization is not about making the bike faster, but about enhancing its visual impact.
Next, focusing on Bosozoku bikes, we will introduce the essential parts needed to customize a bike into a Bosozoku style.
What are the essential custom parts for Bosozoku bikes?
Here, we will individually introduce the necessary parts for customizing a motorcycle into a Bosozoku bike.
We will explain the role of each part, and to help those who don't know where to buy them, we will also introduce some actual products being sold for certain parts.
Please use this article as a reference for building your Bosozoku bike.
Handlebars (Oni-han)
Source: https://bikeman.jp/
Oni-han is short for "oni handle" (demon handle) and refers to handlebars that are narrowed in the center with the tips extending diagonally upwards, resembling demon horns.
Oni-han, with its narrowed center and angled bar ends, also has the advantage of being less likely to break if the motorcycle falls.
However, extreme angles can interfere with clutch and brake operation, so a balance between appearance and practicality is necessary.
Rocket Cowl
Source: https://bikeman.jp/products/acp-1180
A rocket cowl is a fairing that extends from around the fuel tank towards the headlight. Originally used by cafe racers, it later became popular on Bosozoku bikes.
There are "full cowl type" and "half cowl type" depending on the cowl's coverage area.
A full cowl type rocket cowl covers from the bottom of the engine to the headlight, while a half cowl type covers from the headlight to around the top of the engine, leaving the engine and exhaust pipes visible.
Headlights also come in a single round type and a "dual type" with two small headlights.
Windshield (Fubo)
Source: https://bikeman.jp/
A windshield (fubo) is a screen mounted above the headlight. While it changes the appearance of the bike, it also serves as a wind and rain deflector while riding.
It also protects the rider from small stones flying from the vehicle ahead and insects in the summer, so the windshield serves both to change the appearance and to guard against objects and weather hitting the body.
By modifying the windshield mounting brackets, it can be raised higher to achieve the Bosozoku style windshield.
Fire Pattern
Source: https://tantora.jp/nologin/tantora-champ/article/sample0097
A fire pattern is a design featuring flame-inspired colors.
Fire patterns can be monochromatic or feature gradients, and there are various types as colors and pattern shapes are chosen based on preference.
Fire patterns can be found on various parts of the motorcycle, from a small section to the rocket cowl, fuel tank, and front fender, and even on helmets.
Three-Tier Seat
Source: https://ma728ko.ocnk.net/product/102
A three-tier seat refers to a motorcycle seat where there are steps between the rider and the tandem (pillion) seat, and then further steps or an upward-curving type of seat behind the tandem, creating three levels of height.
This is a part where the rider's individuality is strongly expressed, with car speakers embedded in the backrest-like section behind the tandem, or with lettering and decorations.
Straight Pipe Muffler
A straight pipe muffler is a type of muffler that has no internal obstructions, such as silencers, for the purpose of muffling exhaust noise, meaning the exhaust from the engine exits directly.
Because there are no obstructions like silencers, the sound deadening effect is almost zero, and even at idle, a rattling sound like an exhaust leak is produced.
The volume, especially at high RPMs, is tremendous, making it a classic muffler shape for Bosozoku, who rev their engines to high RPMs.
Tail Cowl
Source: https://twitter.com/yoshikichi0321/
A tail cowl is a fairing that extends from the bottom of the motorcycle seat to the taillight.
This is a part where individuality can be expressed, with designs inspired by the tail cowls of classic motorcycles like the Z2, or the so-called "ebi-zori tail" which curves sharply upwards at the end.
The standard tail cowl often coordinated with Bosozoku bikes is made by BEET, featuring a type that is narrowed like a plate and curves upwards at the end.
Zoku-Bo (Gang Pole)
A Zoku-bo is a pole attached to the front fork and extending upwards.
While Hinomaru (Japanese flag) or team flags are sometimes displayed on a Zoku-bo, its roots are surprisingly found in the press riders of newspaper companies.
In the 1960s and 70s, at a time when only cameras were available for incident photography and communication methods like email did not exist, it was the press riders' job to quickly deliver developed film to the company on their motorcycles.
Press riders, who needed to deliver film quickly for scoops, rode at high speeds with the film. To identify themselves as journalists and encourage other traffic to yield, they would extend a pole from the front of their motorcycles and attach their company's flag to it.
The pole used by press riders was then adopted as the Zoku-bo on Bosozoku bikes.
Yankee Horn
Source: https://media.dmm-make.com/item/1915/
A Yankee horn is a horn (klaxon) that produces a high-pitched sound at a loud volume, shaped like a brass instrument or trumpet.
There are various types of Yankee horns, such as those that play chords by installing multiple horns, horns that sound like a Shinkansen train, or those that play the theme from "The Godfather."
By installing an air compressor, an even louder sound can be produced.
12 Popular Bosozoku Bikes! A Summary of Custom Bikes by Popular Model
Here are 12 popular motorcycle models that serve as bases for Bosozoku bikes.
We will introduce models from all four major Japanese motorcycle manufacturers, so you can find the perfect base for your desired Bosozoku bike.
1. Honda CBX400F
Source: http://fanblogs.jp/fore168/archive/225/0
The Honda CBX400F is a 4-stroke, 400cc naked bike released by Honda from 1981-1983, with a re-release in 1984.
It is characterized by its distinctive red and white color scheme, and the combination of a CBX400F with a BEET seat cowl was a classic.
It remains a consistently popular model as a base for Bosozoku bikes, among Kyusha-kai, and other riders. While well-preserved CBX400Fs are becoming rarer, they are still traded at high prices as of June 2024.
2. Honda CBR400F (REV)
The CBR400F is a naked bike sold by Honda from 1983 to 1986, characterized by its fairing located below the engine.
The CBR400F is equipped with a REV mechanism, which changes from 2 valves to 4 valves at 8,500 rpm, meaning valves are deactivated according to engine speed. This allows riders to enjoy a sudden change in exhaust note to a high-pitched sound at high RPMs.
3. Kawasaki Z400FX
The Z400FX is a naked motorcycle sold by Kawasaki Heavy Industries from 1979 to 1982, and has long been popular as a vehicle for bosozoku gangs and kyusha-kai (classic motorcycle clubs).
Immediately after its release, it gained immense popularity as a bosozoku vehicle and appeared in manga such as "Shippu Densetsu Tokko no Taku" and "Shonan Bakusozoku," which were themed around bosozoku, further accelerating its popularity.
It was often used as a base for bosozoku customization, making it almost impossible to find an unmodifed Z400FX. Even if one is found, it's a legendary motorcycle that can fetch millions of yen.
4. Suzuki GSX400E
The GSX400E is a naked motorcycle sold by Suzuki from 1980 to 1981. The successor model, the GSX400E, released in 1982, came with a bikini cowl and was called the GSX400E Katana.
The GSX400E featured Suzuki's unique TSCC (Twin Swirl Combustion Chamber) technology, which generates two swirls from the fuel-air mixture to accelerate combustion and produce more power.
Thanks to TSCC, the GSX400E was able to produce 1 horsepower more than Kawasaki's Z400FX, which was released the year before the GSX400E.
5. Suzuki GSX400F
Source: https://bikeshop-zero.com/bike.php?bike_id=606
The GSX400F is a naked motorcycle manufactured by Suzuki from 1981 to 1983. It was Suzuki's first 400cc class model to feature an air-cooled, 4-stroke, 4-cylinder engine.
In 1982, the year after its initial release, a GSX400F with a distinctive two-tone body color was launched, which was a reinforced model primarily around the front fork.
6. Honda Hawk II / Hawk III (Bab)
Source: http://honda17gd3.cocolog-nifty.com/blog/
The Hawk II and Hawk III are naked motorcycles that Honda began selling in 1977, and are grade names for the 400cc models within the Hawk series (250cc, 400cc).
The Hawk II was launched in 1977, and in January 1978, the "Hawk Hondamatic" model, equipped with an automatic transmission, was released.
In August 1978, the Hawk III, a remodeled version of the Hawk II, was released. Various changes were made, including switching to a semi-flat handlebar, increasing the fuel tank capacity, and upgrading the front brake to a double disc setup.
Source: https://tantora.jp/nologin/tantora-champ/article/sample0085
The CB250T is a naked motorcycle, also known by its nickname "Bab," released by Honda starting in 1977.
The origin of the nickname "Bab" comes from its exhaust sound, which resembles "Ba-boo."
The CB250T was positioned as a sister model to the CB400T Hawk, but the CB250T, with its smaller engine, had a higher-pitched exhaust note, and the endearing "Ba-boo" sound was more distinctly audible on the CB250T.
7. Yamaha XJ400
Source: https://gramho.com/media/2287788871714089220
The XJ400 is a naked motorcycle sold by Yamaha from 1980 to 1981, also known by its nickname "PeKeJee."
Following Kawasaki's Z400FX, it was introduced to the market as Yamaha's first DOHC 4-cylinder naked model.
In 1981, successor models were released, including the XJ400D with twin exhausts, the XJ400SPL with pullback handlebars and a teardrop tank, and the XJ400L, a model for riding schools.
8. Kawasaki Zephyr 400
Source: http://garageone.co/?p=10212
The Zephyr 400 (ZEPHYR) was a naked model introduced by Kawasaki Heavy Industries in 1989, during the peak of racer replicas, and it ignited the naked bike boom.
The Zephyr was an explosive hit, especially among riders who disliked faired motorcycles, leading other manufacturers to introduce naked bikes to the market one after another.
Compared to motorcycles from other manufacturers, the Zephyr was not particularly high in terms of specifications, but it maintained high popularity as a base model for bosozoku customization.
9. Suzuki Bandit 250 / Bandit 400
Source: https://minkara.carview.co.jp/
The Bandit 400 is a naked motorcycle sold by Suzuki from 1989 to 2000, characterized by its unique frame structure.
The Bandit 250 and 400 share the same diamond-structured frame and are equipped with a 4-stroke, water-cooled, 4-cylinder engine.
Despite a minor model change in 1995, it remained a long-selling Suzuki motorcycle, continuing to be sold for 10 years until its discontinuation.
10. Honda VT250
Source: https://cartune.me/notes/uJkKZlYoEy
The VT250 is a 250cc naked motorcycle released by Honda in 1982, equipped with a V-twin engine.
"VT" stands for V-twin, and the VT250 was developed by incorporating racing technology to create a motorcycle with specifications comparable to a 400cc.
The VT250 spawned many derivative models such as the VT250F and VTZ250, collectively known as the VT series. The VT series became a bestseller, achieving the feat of selling 100,000 units in Japan within just three years of its release in the class above 125cc and below 250cc.
11. Yamaha RZ50
Source: https://minkara.carview.co.jp/
The RZ50 is a naked-style motorcycle that Yamaha sold from 1981 to 2007, equipped with a water-cooled 2-stroke single-cylinder engine.
When racer replicas became dominant, sales of the naked-style RZ began to decline, leading to the TZR succeeding the RZ50 and its temporary discontinuation. However, with the wane of the racer replica boom, it was revived in 1998 as the second generation.
Although the first and second generations share the same model name, their concepts and exterior styles differ significantly.
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