I didn’t think it would be a big deal going from a mountain bike with 27.5-in. wheels to a one with 29s, but I was wrong in one area: when it came to transporting them on our Yakima HoldUp bike rack. According to Yakima’s site, the HoldUp fits 20- to 27.5-in. wheel sizes with tires up to 3.0 in. wide and 29-in. tires up to 2.5 in. wide. Our 2020 Cannondale Habit Neo 2s have 29x2.6 tires, which are wider than the accepted diameter by a mere 1 mm. The only conclusion I can reach is that the tire must be taller by a significant amount because the arm that secures the front wheel was not even close to clearing our 29x2.6 tires. In doing some searches, I could see that others have run into the same issue; they addressed it by having the arm come up just on the front of the wheel, but I just never felt that would secure the bike well enough, especially on rougher roads.
Rebuilding the rack can be done in minutes with just a few metric wrenches. I made this modification on the original gray HoldUp, but it can be done just as easily on the current black HoldUp and HoldUp +2. The only real downfall of this mod is that the arm will be on the inside of the front wheel and the adjustment button is a tad more difficult to access. The visual cue that you did it correctly is that the Yakima logo will be upside down when the rack is up and not in use (along with the, "Dude, you put your rack together wrong" comments).
According the Yakima website, the HoldUp Evo can accommodate a wheel up to 29x4.8, so I can assume it will not require this hack. If someone has used the HoldUp Evo with a 29er, please feel free to share your experiences in the comments section.