RACING
- Machine Rules:
- - Automatic Superstock (ATSS)
- - 115cc Superstock (115SS)
- - 115cc Sports Production (115SP)
- - 135cc Superstock (135SS)
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National Motorcycle Sports & Safety Association (NAMSSA)

Machine Rules for Automatic Superstock (ATSS)
Eligibility of motorcycle Automatic Superstock
Only the following models are eligible for this category:
- Yamaha Mio
- Yamaha Mio Soul
- Yamaha Nouvo
(Internal Model Designation: AT115C-51C1; AT115C-2D51) - Yamaha Mio Fino
General specifications
The following items MUST NOT BE altered:
- Type of engine, number of cylinder, valve, piston bore and stroke.
- The material and casting of cylinder, cylinder head, crankcase and gearbox. Except for installation of additional clutch relative to crankcase covers.
- The materials and specifications of the internal parts of the engines.
- Position of the cylinder head and cylinder relative to crankcase cover.
- The materials, casting and shape of crankcase cover. Except for installation of additional clutch relative to crankcase covers.
- The materials, dimensions and shapes of crankshaft assembly.
- Fuel tank (excluding inlet opening and fuel cock). Carburetor for that model.
- Transmission, except the roller weights.
- Frame body, rear swing arm.
- Frame body must remain as originally produced by the manufacturer.
- Front Fork and under bracket complete.
- Original thickness of the cylinder head gasket and cylinder block gasket.
- Original throttle mechanism.
The following items may be altered, but must conform to the general specification. (This is for clarification only. Other parts not listed in the above can be altered or replaced. Change of specification means modification, changes or removal of the parts.)
- Original fuel tank cannot be modified or relocated.
- Change of fuel pipe and fuel pet cock / on / off valve.
- Change of exhaust pipe and muffler, but must have silencer (Carbon Fiber & Kevlar permitted).
- Modification or removal of air cleaner box is permitted; air filter element may be replaced or removed. Air funnel or velocity stock permitted.
- Kick starting device may be removed.
- Removal of speedometer (including meter gearbox and cable).
- Removal and modification of drive case and cover. Transmission components may not be changed. Use of lighter or heavier roller weights are allowed, dimensions should be same as stock.
- Change of final gear ratio is not allowed.
- Maximum width of rims must be as follows:
FRONT: 1.2 inches
REAR: 1.6 inches. - Modification and change of rear / front brake pads / linings is allowed. Conversion from drum to disc brakes not permitted.
- Modification and change to brackets and pegs including footrest.
- The rear suspension shock absorber may be replaced.
- Extension of engine support is not allowed.
- Removal of dust seals.
- Handle bars and front brake lever may be changed/modified/altered by an after market copy.
- Steering dampers are not allowed.
- Materials of streamlining (bodywork), shape and material of seat & cowling (However, expensive material such as carbon fiber and Kevlar are not allowed).
- Removal of rear mudguard. Body must retain original silhouette.
- All lubricants are free.
- Adjusting any parts are allowed. (Adjusting is defined as: "To select each part or assembly complete within the limit of single or total tolerance"; i.e. that of valve clearance.
- Cutting unnecessary stays is not allowed (including part of seat-rail).
- Flywheel and ignition must be standard as manufactured.
- Front disc brake must be original. Pad material and brake lines may be changed to aftermarket parts.
- Original electrical starting system may be removed.
- Modification and change of carburetor is not allowed. Carburetors jettings may be altered.
- Modification and change of the ignitions system is not allowed.
- Modification and change of any of the cylinder head component is not allowed.
- Front suspension unit must remain as originally produced by the manufacturer, however the internal parts of the fork can be modified.
Bodywork
All plastic bodywork parts must be complete, otherwise mentioned above, and should be properly fastened.
Fuel
Fuel must be UNLEADED only and locally available at retail outlets. Fuel test for samples shall be done during post event tech control.
Tires
Slicks and hand cut are not allowed.
The following items must be altered if the motorcycle does not comply
- Motorcycles must be equipped with a functional ignition kill switch (within reach of hands while hand grips).
- Removal of equipment, i.e. stands, rear view mirror, auxiliary and turn signals. Headlight, tail light and signal light lenses may be taped.
The following are not allowed
- Use of special materials such as magnesium light alloy, reinforced carbon fiber, etc. when modifying or changing parts. Except for exhaust silencer.
- Light alloy in the construction of front and rear wheel spindle shaft.
Noise control
Exhaust must have silencer.
Eligibility of competitors
All Novice & Beginner riders may compete in this class. Riders below 18 years of age would require parent’s consent. Expert riders classified by NAMSSA are not allowed.
Interested? Contact us!
- Office Address: 16-A Makiling Street, Hacienda Heights, Marikina City
- Telephone no.: (02) 571-5945, Mobile no.: (0927) 272-7145
- Email address: yamahagrandprix@gmail.com
