B.O.B.L. REGULATION
“BOBL” is an abbreviation for “Battle of Bottom Link.” This is a road race event in which only motorcycles manufactured up to 1964 with bottom link suspension can participate. Our philosophy is to “recreate the golden age of motorsports in the 1960s,” and we hope to convey the joy of road racing to a wide range of people, from beginners to experienced racers. We aim to create an event where participants and viewers can enjoy the atmosphere of the 1960s racing scene.
Held class
GP Class 50 (Under 60cc / Yearly Ranking)
Nomal Class 50 (under 60cc/yearly ranking)
Modified Class 50 (Under 60cc)
Open Class 90 (Under 100cc)
Endurance (Normal class 50 vehicle used)
Article 1 Participating vehicles
1. In principle, participating vehicles are limited to motorcycles with a displacement of 100cc or less with a bottom link suspension system, produced before 1964.
2. However, the organizer will decide whether or not to participate in the model that has been continuously produced as the same model. Please be sure to ask the secretariat for a decision on acceptance or rejection before entering.
Article 2 Engine
Displacement
It is possible to increase or decrease the displacement by increasing the bore of the engine, but it is a condition to participate in the corresponding class with the changed displacement. Please be sure to ask the secretariat for the judgment of the participating class before entering. Any change from the original number of cylinders is not permitted.
Supplementary provisions
Modifications that significantly change the appearance of the engine are prohibited. The judgment is decided by the authority of the secretariat.
Valve mechanism
Any change from the original structure of the valve mechanism is prohibited.
Valve
1. Prohibition of changing the valve diameter and valve material.
2. Prohibition of changing the rocker arm ratio, material and structure.
Cam
1. Prohibition of machining camshafts. (build-up, base circle, etc.)
2. Prohibition of valve lifter machining.
Cylinder
1. Prohibition of changing the compression ratio by machining the cylinder.
2. Prohibition of changing the material of the cylinder.
Piston
Prohibition of changing the compression ratio by piston processing. (build-up)
Head
Prohibition of changing the compression ratio by machining the combustion chamber.
Ignition method
1. Prohibit use of non-contact type and CDI. (Use normal point)
2. Prohibit significant weight reduction.
Crank
Prohibition of weight addition and stroke change.
Carburetor
1. The use of flat slide carburetors is not permitted.
2. Up to 20mm in diameter.
3. GP50 class has no caliber limit.
Transmission
Modified vehicles using T/M such as C50 and C115 will participate in the modified class.
Cooling device
1. According to the mechanism at the time of production of the vehicle. (Prohibition of water cooling for air-cooled vehicles)
2.Installation of an oil cooler is permitted.
Kick starter
Normal class (N50) vehicles cannot remove the kick starter. However , the HONDA C102 early type vehicle with a starter motor is an exception because it does not have a kick starter from the time of shipment from the manufacturer. However, if you are thinking of participating in an endurance race, please check with the secretariat in advance. GP50 class can be removed.
Clutch
Mechanisms that leak oil to the outside are not permitted for both dry and wet systems. Modifications from the specifications at the time of shipment from the manufacturer are not permitted.
Modified Class 50/Open Class 90 Special Rules
・It is possible to change the ignition method.
・It is also possible to modify the transmission.
Specifications change list × marks indicate that specifications cannot be changed.
Article 3 Frame
1. As a general rule, we do not allow the use of frames that deviate from the original. Please be sure to ask the secretariat for a decision on acceptance or rejection before entering.
2. Remove both the center stand and side stand.
ARTICLE 4 Rear Swingarm Suspension
1. As a general rule, swingarm shapes other than original ones are not permitted.
2. Square cross-section, elliptical cross-section tubes, and tapered types are permitted only if they are of the same material and shape as the original.
3. The use of a separate reservoir rear shock unit is not permitted.
Article 5 Front Forks
1. Limited to bottom links. (Internal dampers and springs can be modified.)
2. Telescopic forks cannot be used.
3. As a general rule, diversion from other car models is impossible.
＊ If anything is unclear, please ask the secretariat for a ruling.
Article 6 Brakes
1. The front and rear drum brakes must be equipped with independent operating systems. The use of disc brakes is prohibited.
2. Rear wheel handle brakes are prohibited.
ARTICLE 7 Handlebars
1. The width of the left and right ends of the handlebar must be at least 300mm. In addition, the cutting angle should be 20 degrees or more on each side.
2. Grips and levers must have a clearance of 20mm or more from fairings, etc.
3. The clearance between the handlebar and the fuel tank must be 30mm or more.
4. Process the grip end so that it is closed.
Article 8 Clutch/Brake Levers
Each lever end of the clutch/brake must be spherical.
Article 9 Footrest Pedals
The ends of footrests and foot pedals must be rounded to a diameter of 20mm or more and a radius of 8mm or more. Or it must be covered with rubber.
Article 10 Rims and Wheels
1. All vehicles must be equipped with front and rear spoke wheels. Installation of cast wheels is prohibited.
2. The maximum rim diameter is 18 inches. Other rims are not permitted unless they are the original size.
3. The maximum rim width is WM1 (1.60), other rims are not allowed unless they are the original size.
4. The minimum rim diameter is 15 inches, and the rim material is limited to aluminum and steel.
Article 11 Tires
Only commercially available on-road bias tires for public roads are permitted. However, the use of grooved racing tires (bias) developed and sold exclusively for classic races is permitted.
ARTICLE 12 Fuel Tank
1. As a general rule, only steel and aluminum alloy products are permitted.
2. Only in the case of FRP, use is permitted on the premise that the interior is completely filled with explosion-proof material. If the fuel tank has a breather hose, it must be fitted with a one-way valve and connected to a catch tank with a capacity of 250cc or more.
3. In the case of a rubber stopper type tank cap, it is essential to take measures against tipping over.
Article 13 Oil catch tank / Gas tank
1. All vehicles must be fitted with an oil catch tank with a capacity greater than its displacement.
2. Attach a drain bolt to the catch tank as much as possible.
3. Be sure to install the discharge side breather hose from the oil catch tank toward the intake side of the carburetor. It is essential when installing a breather by remodeling the oil filler cap.
4. Regarding normal breather cars, there are places where it will be compulsory depending on the circuit where it will be held in the future, so we recommend that you take measures in advance.
5. Normal Breather If you remove the breather from a car, attach the hose and return it to the oil vat.
6. Gasoline catch tank must be installed on all vehicles.
ART.14 OIL UNDER TRAY
1. Attach the oil under tray to the bottom of the engine.
2. The oil under tray must have a structure that can hold half the engine oil capacity. Please install a drain bolt as a measure against rainy weather.
*2-stroke vehicles do not need to be installed.
Article 15 Wiring
Please be sure to wire the required wiring points as instructed by the secretariat.
1. For places where it is difficult to wire, such as inspection caps, fix them with packing tape, etc.
2. Carburetor float separate models such as C100 and C105 require installation of a float lock screw. Install the wiring bolt.
3. Use a wire diameter of 0.6 mm or more for the wiring wire.
*Be sure to bend the ends of the wiring bolt.
*We sell wiring bolt. Please contact the secretariat.
required
1.fuel line
2.Oil lines and drain bolts for oil catch tanks, etc.
3.muffler bolt
4.exhaust flange bolt
5.Axle shaft (front, rear)
6.swing arm pivot
7.oil filler cap
8.Brake torque rod (front, rear)
9.Externally exposed springs (rear brake, exhaust, etc.)
ART.16 Sprocket Guard
1. Install front and rear sprocket guards to prevent entanglement between the rear sprocket and drive chain.
2. If there is no possibility of entanglement between the rear sprocket and drive chain due to the structure of the exhaust pipe, etc., the sprocket guard is unnecessary.
*A sprocket guard is not required for vehicles equipped with fairings.
Article 17 Exhaust System
1. Exhaust pipe must be shaped to discharge to the rear of the vehicle. Also, the exhaust pipe must not protrude beyond the vertical line of the rear wheel highest point.
2. Straight pipe is prohibited. And it is obligatory to install an effective silencer. If the volume is extremely loud, the organizer may decide to cancel the race.
3. Exhaust pipe and silencer materials are limited to steel. This is not the case for 2-stroke silencers.
Article 18 Fairings
FairingsWhen installing the fairing, be sure to meet the following conditions.
・The front wheels must be clearly visible from both sides.
・The longitudinal length of the fairing must be between 50cm forward of the vertical line on the front axle and the vertical line on the rear axle.
・The minimum ground clearance of the fairing is 100mm or more.
・With the rider on, the parts other than the forearms must be visible from above, behind, and from both sides.
・Any rear facing part of the fairing shall have a rounded leading edge.
・The number on the front of the fairing must be slanted within 30 degrees.
・The rear wheels must be visible over the rear 180° circumference of the rear wheel perpendicular.
・Use of bikini cowl is prohibited.
Article 19 Fenders
1. The front fender must be installed so that it covers the outer circumference of the tire by at least 100 degrees.
2. For vehicles equipped with fairings, the rules for having a front fender do not apply.
Article 20 Things to remove from the vehicle
The following parts must always be removed.
・Lights such as Headlights
・Taillights
・Blinkers, etc.,
・Rearview mirror
・Center stand
・Side stand
・License plate for public roads
・Guards such as bumpers
Article 21 Prohibited parts, etc.
The following are prohibited.
・The use of superchargers such as turbochargers and superchargers is prohibited.
・The use of light alloy front and rear axle shafts is prohibited.
・The use of alcohol fuels such as methanol is prohibited.
Article 22 Hazard prevention
Hazard Prevention
1. Remodeling that endangers both yourself and others is prohibited.
2. Vehicles deemed dangerous by the race officials during the vehicle inspection will be disqualified from running.
*If anything is unclear, please ask the secretariat for a decision.
ARTICLE 23 CHANGES TO VEHICLE RULES
These regulations are subject to change with advance notice from the Secretariat.
Article 24 Bib Plate
1. Vehicles must bear the assigned number on the front and both sides of the vehicle.
2. Each plate must be oval (21 cm long and 25 cm wide).
3. Numbers must always use Arabic numerals and must be clear and easy to see.Fluorescent colors are not permitted for both plates and numbers.
GP Class 50 / black base, white letters
Normal Class 50 / black base, white letters
Modified Class 50 / green base, white letters
Open Class 90/red base/white letters
Article 25 Equipment
1. The helmet must be a full-face motorcycle helmet for on-road use.
2. Please use a helmet that is marked SNELL, DOT, CE/ECE, or MFJ. It is prohibited to use helmets that have decorations listed on them at the time of sale. (Please check with management for details)
3. Helmet remover will be compulsory.
4. Both the top and bottom of the wear must be made of leather.
5. Wearing a spine pad is mandatory.
6. Shoes must be leather boots without laces.(Use boots that are long enough to cover your ankles.)
7. Wear gloves that do not expose your bare skin while riding. If your bare skin is exposed during the race, you will be subject to a black flag.
*Racing gloves with guards are recommended.
*Helmets that do not have a chin strap cannot be used.
Article 26 Use of Intercoms and in-vehicle Cameras
1. The use of intercoms is prohibited for both sprint and endurance races.
2. In-vehicle cameras are prohibited from being attached to helmets, clothing, etc.(Can be installed on vehicles)
3. If you have installed an in-vehicle camera, please have your vehicle inspected with it installed.
Article 27 About race entry
If you are participating in the sprint race, please check the items in Articles 29 to 31 for which you will participate.
Regarding endurance races, please check Articles 30 and 31.
important points
・We do not accept entries for just the endurance race. The condition is that someone from the endurance team participates in the sprint race.
・Even for those who are only participating in the endurance race, it is mandatory to register in the ・morning, sign a pledge, check equipment, and participate in the briefing.
Article 28 GP Class 50
The GP class is a race with a fixed number of participating riders throughout the year. This class requires speed and dignity in racing.
GP class Vehicle
The following modifications are possible from a vehicle similar to Normal Class 50.
・There are no restrictions on carburetor diameter. However, use of flat valve carburetors is prohibited.
・Kick arm can be removed.
Race
・There are 1 or 2 races per day.
・The number of laps in a class may change depending on the circuit being held.
Grid
・The grid will be determined by a ping pong ball lottery.
・There are circuits where you can change the direction of travel by flipping a coin just before the race.
How to Start
It’s a push start.
Race results
・Points will be added for each race and awards will be awarded for each race held.
・The champion will be determined by the points earned during the year.
・There will be demotions for players with lower rankings during the year, and promotions for Normal Class 50 players who have achieved good results.
・If you have not completed half or more of the specified number of laps (4 laps in case of 7 laps), you will not be able to earn points.
1st place 25pts 2nd place 20pts 3rd place 16pts
4th place 13pts 5th place 11pts 6th place 10pts
7th place 9pts 8th place 8pts 9th place 7pts
10th place 6pts 11th place 5pts 12th place 4pts
13th place 3pts 14th place 2pts 15th place 1pts
Article 29 Normal Class 50
For normal classes, the number of classes increases or decreases depending on the number of participants. Currently, races are held in A class (N50A) and B class (N50B) depending on the circuit. If there are many participants, we will prepare C class (N50C).
Class A will be given to the fast racing speed. The allocation of each class will be decided by the secretariat.
*Participants with racing experience (past or current MFJ competition license holders/international/domestic B and A1) will have their class adjusted. Please contact the management office in advance.
Race
・1 or 2 races per day
・Classes will be divided based on the number of participants.
・The race is scheduled to consist of 15 to 20 cars per class.
・Differences in speed are taken into consideration and the vehicles are divided into classes A to C.
・The number of laps in a class may change depending on the circuit being held.
Grid
The grid will be determined by a ping pong ball lottery or by a lottery held by the operator in advance.
Race results
・If there is one race per day, the award will be based on the result.
・If there are two races in one day, the overall ranking will be determined by adding up each race. In case of a total tie, the second race ranking will take precedence.
How to start N50A, N50B (N50C)
Previously, rocket starts were OK, but now to prevent accidents, the starting method has been changed to first gearing into 1st gear and starting with both feet on the ground.
*Rocket start is a method of starting with the clutch disengaged or in neutral, then suddenly engaging the clutch.
1.Engine start signal
2.Put the gear in 1st gear and put both feet on the ground.
3.Starts with waving of the Japanese flag
Article 29 Modified Class 50 / Open Class 90
This class is a mixed race.
Race
・There are 1 or 2 races per day.
・We plan to divide the classes depending on the number of participants.
・The number of laps in a class may change depending on the circuit being held.
Grid
The grid will be determined by a ping pong ball lottery or by a lottery held by the operator in advance.
Race results
Prizes will be awarded for each class.
・If there is one race per day, the award will be based on the result.
・If there are two races in one day, the overall ranking will be determined by adding up each race. In case of a total tie, the second race ranking will take precedence.
How to start
It’s a clutch start.
Article 31 Endurance Race / E.O.B.L.
1. Vehicles participating in endurance races will follow the Normal Class 50 regulations.
2. Participation with 3 or more riders per team.
3. The start will basically be the Le Mans style, but it may be a rolling start depending on the weather.
4. Use of intercom during the race is prohibited.
5. Overtaking after the checkered flag is prohibited. (To confirm ranking)
6. After the competition, please line up on the pit road in order according to the instructions of the organizer. Competitors will confirm the finishing order. (Depends on race venue)
7. At some race venues, you will be asked to act as a course marshal.
8. When driving on pit road, please be careful of pedestrians and spectators and drive slowly.(Violating teams will be penalized)
9. E.O.B.L. (Endurance of Bottom Link) has different race times and methods depending on the year it is held.
Special rules /Night Endurance Race
- Headlights and taillights must be installed.
- It is possible to remove the front bib when installing the headlights.
- Headlights must be at least 15W and at least 10cm in diameter. Tail lamps must be at least 5W and at least 2cm in diameter.
-The headlights will turn on during the race, so a light switch must be installed.
*LED bulbs cannot be used.
*If the light is insufficient or difficult to see, you may be subject to a Black Flag.
Gasoline refueling
- Each team, please prepare a gasoline carrying can. (Please prepare a metal can that can hold more than 5L.)
- Please enter the bib number so that you can identify the carrying can of your own team.
- Before starting the endurance race, the gasoline in the tank of the running vehicle will be emptied and a vehicle inspection will be carried out.
- Using the mug prepared at the gas station, you refuels 500ml of team’s gasoline and get into position on the grid.
- After the start, he can refuel 500ml per pit stop.(There is no limit on the number of times)
- When refueling, please be sure to stop the engine and refuel.
- You can change riders when refueling. However,Rider after running cannot refuel yourself. Be sure to have at least two people perform refueling work.
- Depending on the race, there may be a handicap. Please enjoy.
- Gas stations will close 15 minutes before the end of the race.
Article 30 Flags
If you are participating in the race, please understand the meaning of the flags displayed by the course marshals during the race. B.O.B.L. uses five types of flags to ensure smooth race operation.
At some racetracks, participants may actually go into the course marshals and wave flags. Please take this opportunity to remember this.
1. Japanese flag
Race start. Used at start.（The red light turns off when there is a signal）
2. Yellow Flag
Danger warning. This means that there is a danger on the course side or on the course. Yellow flags are displayed from one or two posts in front of the hazardous area. Riders should be careful when riding in yellow flag sections. Overtaking is prohibited.
3. Red Flag
Race competition canceled. When the red flag is waved, all competing cars must return to the pits. Please proceed off course with utmost caution. Overtaking is prohibited.
(Rider changes, refueling, etc. are not allowed in the event of a red flag during an endurance race.)
4. Black flag
If there is a problem with a vehicle or rider during a race, it will be waved along with a sign board with a bib number written on it. The presented rider must enter the pits immediately. Presented at the control line post.
5. Checkered Flag
Completion flag. The flag is waved at the control line post and the race is over.Vehicles that fall behind in a lap during the race up to the final lap will end the race on the lap where the checkered flag is waved. (In endurance races, overtaking after passing the flag is prohibited.)
Special Thanks Translation Lawrence ( ＠yokai.motorcycle.engineering )
