I have acquired a tricycle, but it was damaged in transit. I'd prefer they just send me a replacement hub than take the whole thing back, but that depends on me figuring out how to take off the old one.

This is what the hub should look like:

https://picasaweb.google.com/1023634...22244710822002

but this is what it does look like:

https://picasaweb.google.com/1023634...22222222605666

When I unscrew the middle, it's a fairly short bolt which comes out, but after that it's not apparent how to remove the hub (I can see that I'll ultimately need to detach the disk brake, but that doesn't seem to be what's stopping the hub from coming off). Any ideas?

looks like its slides off after the brake comes off and the bolt is out

When I saw the first pic (this is what the hub should look like) I imagined a problem due to the style of spoke holes. Can't say for sure but it looks suspect for strength.

Then I opened the second pic. Even though this happened in transit, it will most likely happen with use as well. A well designed hub won't break like that from shipping damage. I wouldn't want to ride it. I'd send the whole thing back and look for something of better design and quality.

You probably won't be able to get the wheel off until the brake caliper is removed. My guess is that the bolt is threading into a spindle (attached to the frame) to keep the wheel on but doesn't bear weight.

Agreed. And I agree with Red- the design of that hub is very weak.

You are right - thank you.