I'm building a set of wheel for my 73 CB350F and having a bit of trouble. I'm using stock spokes and the shouldered aluminum XS650 rims from Mikes XS. Front wheel laced up fine but I'm having some trouble with the rear. The inner spokes are too long and the nipples run out of thread before they seat. The outer spokes are too short and some of them need to bend before they line up with the nipples, and even then they only have a few turns before the nipples are seated. The spokes should all be the same length, and I know that these rims have worked for others before, so I dont know why they're ending up either way too long or short when laced up.
Any suggestions what I might be doing wrong? I've checked and re-laced these several times and always end up in the same situation.