Having triumphed at the previous Games in Tokyo, the mixed team sprint trio of Cox, Van Gass and Cundy retained their title in style in Paris.
A flawless showing meant they beat Spain by 1.8 seconds, as Australia defeated hosts France for bronze.
For each British rider, this gold meant a differing goal was achieved after contrasting Paralympic experiences to this point in the French capital.
Cox had missed out on the first gold of the Games when she crashed on the first corner of the C4-5 500m time trial on Thursday, having made a bad start, then slipping while trying to correct herself.
The 33-year-old struggled with a calf injury, an eating disorder and a relapse in her multiple sclerosis in the build-up to this event, but overcame all that – plus her Thursday mishap – to claim a fifth Paralympic gold.
Cox admitted she had struggled badly with her mental health after the incident and was nearly crying before going to the start line, but was helped through it by her sprint team-mates.
“I was trying not to tear up before I was on the start line because I was scared,” she said. “I didn’t want to let myself down, it was just the fear of having another wobble.
“I have them in training all the time, doing one in training is something you do not want to do. Being able to overcome that and go better in the final, I’ll give myself a pat on the back.
“These guys have been great cheerleaders, they have given me such encouragement, it’s great to have team-mates constantly checking on you, giving you encouragement, reminding you that you are capable. We’re a great team in general, I wouldn’t have even got on track if it weren’t for these two.”
Cundy added: “I just told her, you’ve done this hundreds of times, just ride it, Jaco and me will be beside you. Get away from us and we will chase you down.”
The 45-year-old Cundy has now won a medal in every Games he has participated in – going back to 1996 in Atlanta – and is now a 13-time Paralympic medallist, having also starred in swimming before switching to cycling.
“I still love the sport, am capable of being at the top end and doing the training I need to,” he said. “For now, being stood on the podium is like nothing else and it brings me back each time.
“In November it will be 30 years representing GB and I still want to keep going. We’ll take it year by year.”
Meanwhile, Van Gass, 38, claimed his second gold in Paris after he retained the men’s C3 3000m indiual pursuit on Friday – just a week after being hit by a car on a training ride which put his participation in doubt.
