I don’t agree. Never say never.

First of all, who says we are just talking about road riding? I actually mountain bike more.

But also, it depends what scenario you are talking about. If the issue is how long of a ride I can do, sure, “strength” per se might not be the issue. But for intense and hard climbs, I think it is (or at least part of it).

If the issue is how long/far I can ride, or the steady pace I can maintain over a longer period... sure, that is pretty much always a muscle fatigue issue, regardless of what kind of shape I am in.

But what typically limits me on super steep (and typically short) climbs in the beginning of the spring definitely has to do with strength, because if I have been doing strength training, it is much less of an issue in the spring.

Remember, the scenario being asked about here is what happens immediately after a long hiatus off the bike. And some people will retain muscle endurance or muscle strength differently in that time off.