The only time people find out is when the brakes are used in anger. We have sourced brake drum friendly lining materials with the same co-efficient of friction as the old, now banned, asbestos material. Using on-board telemetry, we have found that a well fitted cable/rod braked car can stop from 30mph in only a few feet more than a modern car. There really is no reason not to have safe powerful brakes that pull up evenly when you really need it. 

Please click on the link to see a Speed 25 undergoing brake testing. This shows one rear wheel locking which we adjusted out subsequently.