I happen to live near the unicycle.com store in ATL, and when you lift the 26 and 24 Muni cycles off the rack, there is a very noticeable difference. Tire selection makes the 26 attractive, but I’m concerned about the extra weight of the 26".
Because there is a lot more of it. Tire and metal (from the extra rim and frame material).
The weight will only really affect your riding when trying to hop over stuff and pulling the uni up w/ you.
Be thankfull it’s not a Torker. I picked up a similar 26" uni to what you did w/ a 3" tire and it was lighter than my 24" DX w/ a 2.6.
like skilewsi74 said extra metal and a big tire. if you are worried about weight then put on a narrower tire.
Compared to the Nimbus 24", I doubt the extra 1" of frame material on each leg actually amounts to much. The rim is a bit heavier and the 26x3 Duro tire is a lot heavier. You can save a lot of weight by swapping the 26x3 for something lighter.
I recently put together a 26" with Nimbus frame, 32h ISIS hub, 47mm Trial Tech rim, and a lighter tire (Continental Trail King 2.4) that weighs the same as a Nimbus 24".
The tire on the current N26 is very heavy. My brother’s current N26 is much heavier than my older N26 with a narrower and thinner tire. But once you are riding, you don’t notice it that much; I may even be slightly faster on the heavier one because the wide heavy tire absorbs bumps so well.
Might check the tube as well.