Mini Stock Construction Rules

< More Rules

Effective from 10th February 2025

  1. Body;
    1. Must be a reasonable representation of a full size Mini type car.
    2. Brushed class – ABS shells only.
    3. Brushless class – Lexan shells only.
    4. Spoilers are not permitted.
    5. Windows must be fully cut out on ABS shells and be left clear on Lexan shells.
  2. Chassis;
    1. Must be single piece and constructed in GRP only (No carbon mix or special mix GRP), measuring no more than 230mm in length and 100mm in width.
    2. Any holes drilled or cut must be used or filled.
  3. Rear Pod;
    1. Alloy pods are permitted.
    2. The rear pod or axle/motor carrier must be bolted to the chassis with a minimum of 4 bolts.
    3. The motor must be secured by at least 2 fixings.
    4. The design of the motor pod is free.
  4. Bumpers;
    1. External plastic bumpers to be fitted to the chassis front and rear.
    2. Front to be grid style and representative of a full-size mini stock car.
  5. Rolling Chassis;
    1. Overall maximum length of the rolling chassis including bumpers to be 292mm.
    2. Overall maximum width of the rolling chassis to be 163mm.
    3. No suspension whatsoever, including dampers, springs, shocks, “O” rings or notching the chassis.
    4. Wheelbase to be 175mm +/-2mm.
    5. Metal materials used in the rolling chassis may only be steel, brass or aluminium. Special materials (such as titanium) are not allowed.
    6. All added weights must be bolted to the chassis with a nut and bolt except for under-LiPo weights.
    7. Minimum ride height of 3mm.
  6. Tyres;
    1. Min 25mm, max 26mm width and max 60mm diameter.
    2. No min diameter of tyres, but the tyre must cover the entire wheel edge to edge.
    3. Tyre additives are NOT allowed.
  7. Drivetrain;
    1. Diffs are not permitted.
    2. Gearing is open to 32dp or 48dp for pinion and spur gear.
    3. Z-drive style hubs are allowed.
    4. Rolling element (ball) bearings are allowed on the front and rear axles.
    5. Any 12th scale single bolt wheel to be used, mounted onto a steel axle only. GT12/LMP style wheels are not allowed.
  8. Electronics;
    1. Brushed class;
      1. Powered by 4-cell NiMH battery and brushed motor only.
      2. Cell layout is free and open for driver’s choice.
      3. Motors permitted include the Kamtec K21 and Schumacher Core 21.
      4. Speed controller maximum RRP of £60 and must be commercially available.
      5. Electronic speed controller or mechanical resistor type speed controller permitted.
    2. Brushless class;
      1. Powered by 1S hard-cased LiPo battery and 17.5T brushless motor only.
      2. Motors must be on the latest BRCA Motor Homologation List.
      3. ESC must be in BLINKY mode with a max RRP of £150.
      4. All LiPo batteries are subject to a voltage test with a max of 4.2 volts allowed.
      5. A voltage test can be requested by the committee prior to any race. Anyone who fails the test will not be permitted to race that heat, and anyone who refuses to partake in a voltage test may also be removed from the heat/final.
      6. All LiPo batteries must be charged in a LiPo charging sack at a maximum of 10 amps.
  9. All cars must be commercially available to buy;
    1. Parts from other manufacturers may be used as long as they serve the same purpose as the part they are replacing.
    2. Anyone wishing to manufacture a car must go through the process of testing and development at their regular club, with the clubs agreement. If they wish to then race the car at BMCC they must be able to make units available to purchase by other racers. It must comply with the above construction rules if being sold to race, and must be of a comparable price to those being sold by other manufacturers and not overly priced to limit availability.
    3. Anyone wishing to develop or modify a car that does not comply with current BMCC construction rules must ask the BMCC committee for permission to test at a race meeting.
    4. Any changes to the construction rules that allow new designs to race would need to be approved by the BMCC committee.
    5. Championship points will not be awarded if the car does not meet current construction rules, and you will only be able to participate in the lowest final. You will not be able to ‘bump-up’ to the next final.