I tried to fix this at someone else's house. Decided to bring it home to my shop/garage. Within a minute or so I realized the wheel needed a spacer between the non-driveside of the hub and the fork. DUH!!!
Now, bikesonline provides this spacer and it is somewhere in the wheel packaging (it was already unpacked when I arrived), not in the box of tools, pedals and accessories where we assumed everything we needed was. After talking to bikesonline the owner looked again and found it. With the spacer in place I was able to adjust the brakes quickly using the mounting bolts only, the cable already being in a neutral position. The owner wanted me to true the wheel just because, and that was fairly quick too, even without a rim brake to guide me.
Bikesonline claims a 25 minute build, no experience necessary. Yeah maybe, but:
1) no instructions, just a generic and very dated "bicycle manual". We really needed no instructions except "find the spacer and use it!!!"
2) stuff goes wrong: rear rotor ever-so-slightly rubs the pads and can't be adjusted away (bikesonline says it will "seat", iirc, and resolve itself), the chain rubs the FD and can't be adjusted for a wide range of gearing/cross-chaining (chain angle looks strange to me for most of the cogs), front wheel not true (not a functional problem but the owner wants it true!)
I may be back to talk about that FD. Spent 40 minutes trying to eliminate the chain rub, and my take at this point is that they did something funky to get around a design problem. They pre-tensioned the cable to be able to reach the big chainring. The limit screws would NOT position the FD correctly, with the cable slack.
Thx again everyone.
Last edited by sunburst; 08-18-21 at 09:39 PM.