Two locknuts on axle on threaded side of hub: Good, bad, or no difference?

[pocky]

Received the tandem (2001 Burley Rumba) yesterday at work via DHL. It only took them three business days to get it here from FL! It was fun dragging it into my office and putting it together. I was going to ride it home in rush hour traffic by myself, getting what would certainly be fun looks from the passersby, but the better half came with the car and we threw it on the trunk rack (minus wheels of course).

It's a lovely bike, but there's something that's confusing me greatly about the "spacers" on the threaded/drum brake (though we don't have a drum brake) side of the hub. There's the cone, then a washer, then a LOCKNUT, then four more washers/spacers, then ANOTHER LOCKNUT. See the photo below.

I'd like to replace this motley crew with just the cone, one or two big spacers, and the one locknut. It's always been my understanding that there's only supposed to be one locknut on either side of the axle, and it should be the outermost thing. The only thing between the cone and the locknut on either side should be washers/spacers. Right? Is there something about tandems that I'm missing here? If not, is it dangerous to have this double-locknut setup, or will it make no difference?

Thanks for any help you can provide!

[TandemGeek]

Two words: Drum Brake

More information here: http://www.precisiontandems.com/arai.htm

So long as the overall useful axle width (145mm) remains the same so as to hook up with your rear drop-outs correctly, and there's at least one locknut in the string of spacers, no harm no foul.

[pocky]

Two words: Drum Brake
Duh! That actually crossed my mind.

no harm no foul.
Awesome. Thanks!

[zonatandem]

That is the way Burley supplied them from their factory in Eugene. No worry.

[pocky]

Good to know. I guess they put in the various sizes so you'd already have all the spacers you need if and when you wanted to install a drum brake. As for me, I left the two locknuts but replaced the stack of spacers with one long one. Looks cleaner now, and now I've got a bunch of spacers to use for other projects. :) Thanks to both of you for all the info!

Shakedown ride (by me alone) is tomorrow afternoon; by both of us, Saturday morning. Sunday, they close down a large chunk of Memorial Drive (very nice ride if you're ever in Boston) to all motorized traffic, so I think we'll try to really put it through its paces then. I don't think our two short tandem rides so far make us experienced enough yet to ride it in traffic...