IMO as the non-racing put crew, if the WKA is going to error; it needs to be on the side of safety. We were lucky enough to switch from sprint without having to put on front brakes. But it wasn’t long into RR that we had them put on. Maybe only once did the second brake system save my son. The cost was worth it.
I’d have no trouble with experienced r-racers with a single brake system provided that an adequate pre-race inspection was done. A mandatory mechanical log book on the brakes would be good, but don’t see that ever happening. Anyone ever had their rotor pulled and inspected in pre-tech? Probably no one. I’ve pulled rotors and found worn pins or bolts to the carrier or egg-shaped holes in the rotor. And that’s with front brakes.
As for newbies in r-racing, mandatory front brakes. It too easy for an aggressive new comer with no front brakes to chase an experienced driver with fronts way too deep into a corner. You know who’s going to lose in that scenario. Where an experienced RR-driver might be able to save his butt in a case a brake failure, a newbie with a single braking system is not going to have the experience save him/herself and the others around them.
LAD Specialties customer / tony kart / rotax / kt100