Rim width Kris Holm vs Nimbus Oracle (27.5)

Wanting to purchase a 27.5 and noticed the Oracle seams narrow for the 3.25 tire at 42mm. The KH is listed at 55mm with the same 3.25 tire. (guessing these are external rim widths) I have a Nimbus 29 that came with a 3.25. I swapped it out for a 2.8 and it seamed better. Just not sure if this was my inexperience or a narrow rim. Panning to convert the 29 to road and use the 27.5 for muni. That way i have 2 unicycles with about the same tire diameter. I am also getting tired of swapping tires on the 29 to do both.

Any advice on rim width for the 3.25 tire would be appreciated.

The Nimbus rim is 33mm internal, the KH 50mm internal. The KH rim is so wide that it only works well with the Duro Crux 3.25" wide tire. The Surly Dirt Wizard works ok but I think it would work better with a narrower rim, ~40mm internal.

I’d build up a 27.5 from scratch starting with a carbon rim from Light Bicycle or Nextie so you could use a 36hole hub. Or see if you can locate a 32hole uni hub and buy a 32hole carbon rim from a bicycle wheel manufacturer. And I’d aim for 35mm internal which works for tires 2.4" - 3.25" wide.

The nimbus rim is solid but very heavy - 900grams - and does not lend itself to tubeless conversion unless you do it ghetto style which ends up being as heavy as running a tube (but at least it won’t flat). And the Crux tire may rub the inside of the nimbus frame. I’ve also found this true with the KH frame–there just isn’t enough clearance for when you really pedal hard… ZZZZZT, ZZZZT, ZZZZT!

Another option would be to get a 36 for road and make the 29 a dedicated muni ride. Or do what everyone here does eventually–get a uni for every occasion!

Thanks for the advice. I do have a 36 but ride some things that are to steep for me on the larger wheel (maybe I just need more practice). Building a custom rig does sound fun.