I climb the levee-mississippi- as my workout
and I'm old-62- bad knee
and there is thick grass
and it rains making it even worse
So I use the 20 41 -probably 80 rpms 26"-bad knee etc
But when I was younger -I could have done it in any gear-44/28 700c or 27" was just fine when I was 25 yo
The grass and soft surface is nearly as bad as the climbing-since changing your angle doesn't help one bit.