Electric Recognition Board - Motor-speed Limiting Electronic Speed Controllers

Motor-speed limiting Electronic Speed Controllers

This BRCA standard allows all speed control manufacturers to develop and market a speed controller that limits the maximum rotational speed of a brushless motor, irrespective of the motor make or specification.  The intent of this standard is to limit motor rotational speed with a zero tolerance on the upper limit.  In this standard, if it doesn’t say you can do it, you can’t.  We expect to work with manufacturers to update and improve this standard, to make provision for new technology and designs, and so we encourage you to contact us at This email address is being protected from spambots. You need JavaScript enabled to view it..

The ability to control the maximum rotational speed of the motor is known as a rev-limiting speed controller (ESC).  The ESC will not command, or allow, the motor to increase its rotational speed above a pre-set limit.  At all times the speed controller will also comply with the “Zero Timing”, or ‘Blinky’ timing requirements.

The ‘Blinky” profile will ensure that the motor phase drive outputs (A,B,C) change state within 10uS of the relevant motor sensor signals changing. When in this profile, there is no alteration to the fixed mechanical timing of the motor. When the "Blinky" profile is activated, it will be identified by a blinking LED or LEDs while the ESC is armed and in neutral position. Functions that increase the timing such as “Boost” and “Turbo”, or reduce the timing such as “Softening” are not compliant with “Blinky” profile and must not be used. The ESC must not continue to indicate ‘blinky’ mode when any of these functions (or similar) are enabled.  

When an RPM limit is set the ESC must limit the Motor RPM to the specified setting with zero tolerance. It is the ESC manufacturers responsibility to ensure that the tolerance of timing circuitry is designed in such a way that this limit cannot be exceeded. That should include choice of timing circuit, eg resonator, RC oscillator, or Crystal, and must be considered over the expected operating temperature.  Any checks/tests carried out at the track will fail a competitor who is found to exceed the limit.

To deliver a common range of speed limitations for universal use in competition, the range of speed limitations are as follows:

Speed range selection must be easily checked in technical inspection during a race meeting.  Speed range may only be selectable from a range in a table.  User-selected motor speeds are not allowed.  The range given above is the minimum standard required.  The speed ranges must be at least 2000rpm apart.  A unique sequence of blinking LED/s will be provided by the manufacturer to identify the rev-limit selected by the user.

For the open – no speed limitation setting, LED blinking will be as featured for zero-timing ‘blinky’ speedos where speed limiting is not fitted.

Each manufacturer may select their own way to show the speed range selected.  This may be by colour of the LED/s, by the number of blinks for each speed selected, or another unique way of easy, quick visual identification of the rev-limit selected.  

Speed controllers and software will be checked by the BRCA, in a controlled environment, for compliance with this standard.  A list will be maintained and published by the BRCA, of those speed controllers, and their software designation, for use by organisers and competitors.  

The BRCA reserves the right to retain a speed controller after the conclusion of a meeting to measure its performance against the above criteria in a controlled environment. The equipment, or identical new replacements, will be returned to the competitor.  Sanctions may be taken against a competitor and/or manufacturer if a controller is found to be non-compliant.

Current approved speed controllers

To apply for inclusion in this list, please send details of the speed controller and firmware as above to us at This email address is being protected from spambots. You need JavaScript enabled to view it..

Where the software is an update to existing hardware, we will test the software on speed controllers we may already have, or can obtain.  Where the software is for new hardware, we may ask you to provide a hardware sample for testing.

If you have questions, or suggestions for changes and updates to this standard, please email us (This email address is being protected from spambots. You need JavaScript enabled to view it.) and we can discuss your suggestions with you prior to any changes.

Document Attached Below - 

Motor-speed limiting electronic speed controllers

The use of limits on the rotational speed of motors (rev-limiting) is increasingly common.  First used in Euro-Touring Series (ETS), this standard was adopted by the BRCA for their frontie class, and is now in use by many UK events and clubs.

Using the software built into a speed controller, the driver can select from a small range of rev limits, for use in competitions, as specified by the organiser.  For example, BRCA’s 10th Circuit Section specify a rev-limit of 15,000 (15k) rpm for their frontie class.  Many indoor events and clubs are specifying a rev limit of 17.5k rpm for their winter 2024/2025 series’.

Our first standard is designed to open this ever-more-popular capability to all manufacturers by specifying the requirements that make a rev limit the same for all drivers, irrespective of the speed controller used.

The standard includes a list of those speed controllers we have found to use software that conforms to this standard, including all the popular makes currently in use.  We invite manufacturers to send in their speed controller with fitted software for testing and inclusion on this list.  Please contact us through email (This email address is being protected from spambots. You need JavaScript enabled to view it.) so we can get your products into test and onto this list.

If manufacturers have comments about this standard, please email us so we canunderstand your comments, and make updates where we agree there are gaps to close, or improvements to make, for the racers.  This standard will be updated as required to ensure that we maintain a common standard across all manufacturers, taking into account technologies and improvements made to speed controllers.

Clubs, events and series’ can now open their allowable equipment to many manufacturers, which helps the supported drivers promote their products, the manufacturers to sell existing and new products, and the drivers to find competition in the market place to get the best out of their racing budgets.

We are at This email address is being protected from spambots. You need JavaScript enabled to view it. if you want to contact us.

Attached – ERB01/24 Aug ’24

Peter Winton​​Jordan Norwood​David Gale​​Paul Worsley

Chair​​​Board member​Board member​Electric Board Secretary

We expect to have more ERB members in the future, so if BRCA officials would like to join us to represent your Section or Clubsport class, please get in touch at This email address is being protected from spambots. You need JavaScript enabled to view it.