Xtracycle Build - Pics and Questions on Chain Sag

[evangundy]

I sent an email to a friend of mine who put an xtracycle on the back of a Rans crank forward, so I knew he had long chain issues. Here is what he wrote back to me - I'll see if I can find a picture of his setup and post it. Thank you to Ian :-)
Only picture I could find is of the other side of the bike, not the chain side. (taken at the 2008 Recumbent Retreat at Ft Stevens St Park near Astoria Oregon) Doesn't show what he's done to it but does give you an idea of how long his chain is :-0
http://www.recumbentretreat.org/phot...p?image_id=551

Edna

Heya,
Well, I definitely had to deal with chain sag on my setup, considering the RANS is longer to start with.

First thought would be to make sure the chain is the right length. Should be able to shift into the big/big combo and have the rear derailer pulled almost all the way tight. That will put the most tension on the chain, limiting sag. Along with that is trying to be conscious not to use the smaller cogs when in the small chainring.

A second thing I did with my bike was pulled from my recumbent background. Just putting maximum tension on the chain wasn't enough with the loooong chainstays of the RANS. So, I got some sections of chaintube. My first thought was to just put the top run of the chain in tube, because I could tell I would have the same dragging problem she does (yes, I did look at the TE thread at work), and also across my chainstay. Having it in tube takes care of that. I then went a step further and put the bottom run of chain in tube as well. Keeps it from swaying side-to-side as much, and also keeps it a bit more protected from road grunge (which would be more important if I was in Portland than here).

The trick with the tubes is figuring how to use zipties to hold it in place, keeping it from hitting either end. Generally I'll put a ziptie around something on the bike, then ziptie the tail of that one to the chaintube. You can see something similar on many trikes that run chaintube.

The idler is an interesting idea, but I think you'd need to have something like Terracycle's setup where it can move side-to-side. And ya know, chain tube is much cheaper than Pat's wonderful creations.

So, there's how I managed it on my bike. I'd be happy to ramble off some more if I can think of something else.