Originally Posted by
recneps
Honestly the rim is so beefy you should be fine. I have friend at your weight riding on rolf vigors and because the rim is beefy like the 420s youll be fine.
Just a bit of trivia from when I was researching this: the 420 rims are from the same factory, same alloy, same tech as the Niobium 30s. The Niobium 30s are about 20 grams heavier and slightly lower profile, 30mm instead of 34. Given all that, 24/28 in the 30s should be more durable and stiffer than 18/24 in the 420s.