In my climbing group, we consider a weight difference of more than about 25kg to be too dangerous when leading. It’s definitely a safety issue for both climber

In my climbing group, we consider a weight difference of more than about 25kg to be too dangerous when leading. It’s definitely a safety issue for both climber and belayer. At two meters tall and 93kg, by necessity I own an Ohm (by Edelrid), which buys an extra 20kg or so of margin.