For 2020 it is a requirement of Solo Road Race machines to be fitted with Lever Guards as per the 2020 ACU Handbook.
The new Ruling can be found of Page 267 and is as follows;
14.12 CLUTCH AND BRAKE LEVERS 1. All handlebar levers (clutch, brake, etc.) must be, in principle, ball ended or be rounded (minimum thickness of this flattened part 14mm). These ends must be permanently fixed and form an integral part of the lever. 2. The maximum length of control levers measured from the pivot-point to the extremity of the ball must not exceed 200mm. Each control lever (hand and footlevers) must be mounted on an independent pivot. The brake lever if pivoted on the footrest axis must work under all circumstances, such as the footrest being bent or deformed. 3. For all types of motorcycles, throttle controls must be self-closing when not held by the hand. 4 Brake Lever Guards must be fitted. They must be robust, suitable for purpose and properly fitted. Classic or Vintage machines racing exclusively in their own race or event are exempt.
R & G Racing are offering a discount on Lever Guards to ACU Licence Holders -
https://www.rg-racing.com/