Hey, I realized I assumed you were a woman, without any clear indication of that.

Anyway, regardless of which restroom you use, it is really hard to say how much the difference is going to mean to you.

in terms of time on the clock, it wil proably make a small difference, but not enough to determine if you can “keep up”. My guess is that if you are at the back of the pack now, you will still be back of the pack, unless you have been right on the tail of the guy 2nd to last. Then you will be 2nd to last.

It has been a few years since I cared enough to read them, but there have been studies attempting to quantfy the difference between 26” and 29” in terms of lap times around various courses. As I remember, there usually was an advantage to 29ers. But the difference was pretty small, and nothing to go buy a new bike over.

To me, the advantage is more in how they handle rocky terrain. More of a subjective thing than time on a clock.

It is also important to consider WHERE it is you feeling slower than the rest of the A group. Climbs? Rolling flowy stuff? Technical pedally sections? Downhills?

And to reiterate my point yet again: at your hieght, you may prefer a 27.5 over a 29er. And in that case, it gets really hard to make the case for dropping $4k JUST to go from 26 to 27.5. That is really not going to make a lick of difference where you place in the pack.