Help Wheel Building

Normally, I wouldn’t post this here and believe me I have looked on the internet for about a hour or so and cannot for the life of me find any info on what size spokes I need.
Years ago I bought a 36 hole hub for a Nimbus Oregon. I had a spare Large Marge XC rim that was 36 hole and heard that the Oregons were switching to 32 so I figured buy it while I could.
I then injured myself sold off all my complete unis and gave up the sport.
Years later and I am finally over my injury and have pretty much all the parts to build a uni. I have bought a frame for the Nimbus Hatchet. I am positive the Oregon hub will fit as they are pretty similar but I need to build this wheel.
I cannot find anything called Nimbus Oregon hub online which is the name USC used when selling it to me and I have no idea about the Large Marge XC and the ERD. Plus I believe I need two different sizes of spokes for the brake and the non-brake sides.
The hub has the words Nimbus ISIS Drive LT on it.
Again, I know asking for spoke length is not the best but I am desperate to get this thing built and get back to the sport I love.
Any help greatly appreciated.

It looks like the UDC spoke calculator doesn’t have the database for the moment. I would send an email to Roger at UDC.UK with your questions. He most likely will have the published ERD for the rim, and the dimensions for your hub. He may even be able to just tell you what spokes to order based on the published spec’s.

I’m sorry I can’t be more help than this. I think it is better to measure the parts in hand before ordering spokes. It doesn’t usually present any kind of surprise; however, I have had it happen where my measurements were enough different that I was glad I didn’t buy spokes based on the published numbers.

Yes, Roger should have been my first step. It has been quite a while since I was in the unicycle community and I totally forgot about him. I have asked him things in the past and always got good advice.
Thanks for the suggestion.

Check out Sheldon Brown’s website
There’s some good information there, but hopefully Roger can help you.

I tried several spoke calculators when building my fat Hatchet. I have a Surly Clown Shoe rim but somehow the spokes ended up beeing around 5 mm too long on both sides. Luckily my LBS helped me out, and just switched half of the spokes with shorter ones. Am not sure if a really fat (100mm)rim “fits” in the excisting calculators.

I needed to include the centre offset of the holes in the rim into the calculations.
The disc hub offest was also added in.
I can’t remember the exact numbers - but with 18mm hole-to-hole centre offset it was something like:
Disc side = 30mm wide flange to centre = 60mm equivalent, minus 9mm offset = 51mm
No disc = 50mm wide flange to centre = 100mm equivalent, minus 9mm offset = 91mm

I use this one and it is very good

You can also use this one:

Thanks for all the help. I talked to Roger at ADC UK and he gave me some great numbers to work with.
In the end, I ended up just taking the whole thing to my LBS and paying 10 bucks for them to deal with the nightmare of this hub and this rim (which has offset holes).
The man at the LBS told me it took around 4 different size spokes to lace it up. I am not sure if this is accuracte or a good idea but it does seem to roll straight.

Disc side / non disc side will need about 2-3mm difference.
The inner side of the flange / outer side of the flange on each side may need another 1mm difference (I used 12mm nipples inside / 16mm nipples outside on one of my wheels)

So using 4-different lengths to get a perfect fit seems like a reasonable solution.
Most of us won’t have a bag full of different spoke sizes lying around.
It sounds like he has done a good job for you.