Tire clearance on Xtracycle (particularly Swoop)?
 

I have an Xtracycle Swoop that I love - carries three small kids around comfortably. I noticed that my chain is rubbing the tire slightly, only in the lowest gear. Anyone else seen this on an Xtracycle? I've been trading messages with one of their mechanics, and they'll fix it for me, probably either by redishing the wheel or swapping for a narrower tire (although the tire that came on it is stock); I just need to find time to take it to the shop if I want to do that. I don't use the lowest gear often so it's not much of an issue. I am wondering if this is something odd about my bike, or common due to tight clearance on these bikes.
https://cimg6.ibsrv.net/gimg/bikefor...b9a7fe1f97.jpg
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Is it only the bottom run of the chain that the derailleur is holding? Or is the top of the chain that takes the load between your chain ring and cassette cog?

If it is only the former, not the latter - you may be able to adjust your derailleur slightly. Though, that might be touchy. It may make it hard to change gears if you don't have enough inside swing (towards the lowest gear/tire).

If the wheel is centered on the frame (check the centerline of the inflated tire and bike frame) I am not sure I would go the route of changing the dishing of the wheel. You can get some movement in the dishing by loosening the spokes on the drive side and tightening the spokes on the non-drive side. However, that will take the wheel/tire off the centerline if it is already centered. I don't think it would make that big of a difference, maybe not even noticeable, in riding the bike, but it would be an oddity that would bug me.

Another idea is a wider bottom bracket. If you can get the chain rings pushed out a bit that could give you a bit of clearance. I did this on my bike - i added a Mountain Tamer Triple to my triple crank, making it a quad crank - with a tiny inside chain ring - for a super low gear. I can't recall now how far out I went with the bottom bracket, but I got enough clearance I can use the 3x small chain rings - which is all I really use - easy. The 4th largest chain ring is tough to get to unless I am really cruzing down hill and have some speed going.

The smaller tire would be the easiest, most symmetrical solution. You may even be able to get a tire with less tread near the side wall in the same ISO width that would still be physically narrower without "changing the tire size". Just food for thought.