What size, make and model tire?
I’ve been thinking of doing this for a XC uni.
People have successfully fit a Kenda Kinetics 2.6 in a 24" LX. If I remember correctly, the main problem w/ that tire is it was very nearly scraping the crown, there was a bit more space on the sides, so it could work. But do to production varience, some will have more/less clearance.
My 2.6" Kinetics on my DX is 63 mm wide and my 3" Arrow Racing Wide Bite is 67 mm wide (32 mm rim).
The clearance w/ my Wide Bite is very close. It has a very different character than my Kenda, which I prefer since I don’t do any drops yet.
Summary of tires