Xtracycle Build - Pics and Questions on Chain Sag

[kfergos]

After months of fantasizing about converting my old Specialized Hard Rock-turned-commuter bike into a hauling machine, the dream has finally become a reality. I had my bike shop put it all together and I rode it home, fully loaded, for the first time last night. I was very favorably impressed with how well it handles, how stable it felt, and how easily and naturally I got used to the slightly different dynamics. I didn't expect this, but it's actually fun to ride, in a way more so than my speedy custom Seven. The bike's very cumbersomeness freed me from feeling like I should try to go fast, and I just enjoyed taking my time toodling along, marveling at the remarkably stable handling and how it smoothed out bumps, cracks, and potholes. I think of this as my "joke bike" as far as style and looks go; it can do serious work, but I'm trying to make it as unattractive to thieves as possible:







As a side note, if you have any fun or cool stickers you think should grace my bike, feel free to share. I still have the "You'd look hotter in a helmet" sticker I've been saving this whole time to put on this bike. There's something so fun about saying "I'm just going to have fun decorating this thing as outrageously I like!" -- hence also the blue and black speckled bar tape, something I'd never put on a bike whose looks I truly cared about.

Here's my question: The chain is incredibly long, and as a result sags something fierce. The Xtracycle web site doesn't have very helpful information about dealing with chain sag, unfortunately. After trying to use a chain tensioner but not having that work, my bike shop guys put an orange roller thing to hold the chain up, as you can see here:





The problem with this is that as I get into the two highest gears (smallest cogs on the cassette) from the middle chainring, the chain falls off the orange roller. It fell off three times in a 15-minute ride and six times on my normal 13-mile commute. Then I have to stop, flick it back on, and go on. This is incredibly irritating, especially since I don't have an indicator to tell me what gear I'm in, so I can't always tell I'm in a dangerously high gear. Also it always happens when I'm going at a decent pace, usually down a hill, which is just when I don't want to have to slam on the brakes, twiddle with the chain, and then have to muscle it to start again since I'm in a high gear. Plus I live in fear of shifting and hearing it fall off; the other choice is to stay in too-low gears and spin like crazy, but I end up going frustratingly slowly in that case. I'm not usually in a hurry, but I would like to keep up a comfortable, sustainable pace, rather than going at a much lower speed.

So: Do you clever wrench-types have any suggestions for what else we could use to suspend the chain partway along? I'm especially interested to hear how other Xtracycle riders have dealt with this problem.

[Kalidurga]

I'm sorry I'm not a wrench-type and have no suggestions for you, but I do want to say that I think that bike's pretty cool looking. It's got a lotta character.

[Tri Girl]

OK, I don't have any advice, but I had to say that your bike is AWESOME!!!!!
I love how it's turned out- stickers, bar tape, and all!!!!

and now for some real advice...

[Geonz]

Like the rest of me, I just let my chain sag.

It looks totally awesome Watch when you're loading stuff that you don't get the bags caught in the chain... I've got a big ol' hole in mine from doing that. I'm torn between getting a new one and figuring out how to fix that and the busted buckle... or doing something entirely different.

[Fredwina]

On recumbent, we have to have idlers to deal with sag. One thing that's different from what you've rigged and what is on my bacchetta is that I have a strap (looks like sheet metal) to keep the chain on the idler:

Hope this helps

[tulip]

Great bike, kfergos! I, too, have an old Specialized Stumpjumper that I dream of turning into my haulin' machine through an Xtracycle transformation. One of these days I will.

Fredwina' solution looks quite good. I bet a bike shop type could figure something like that out pretty easily. Or maybe they have a deeper roller thing they could put on.

Great work!

[kfergos]

On recumbent, we have to have idlers to deal with sag. One thing that's different from what you've rigged and what is on my bacchetta is that I have a strap (looks like sheet metal) to keep the chain on the idler

Do you know who the manufacturer is for the little rolly thing? Cause that looks like it'd be perfect.

[fatbottomedgurl]

Someday...when I am done with carpool duties and getting kids places... I will own an xtracycle.

[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.

[evangundy]

Here is a link to more pictures of my friend Ian's Xtracycle build up, showing better shots of what he did with his chain - hope some of this helps :-)
http://picasaweb.google.com/ian.hoff...reetXtracycle#

Edna

[kfergos]

Thank you all for your suggestions and ideas! For posterity's sake, I'm posting my solution here. I ended up going with the expensive but ideal solution, an Xtracycle-specific idler built by TerraCycle. They don't list it on their web site (http://www.terracycle.com/Merchant2/...Code=IdlersALL), but when I called and talked to a very helpful guy named Robert Johnson, he told me they had designed something to take care of Xtracycle chains. Installed it looks like this:



You can see the really long bolt with a carefully machined sleeve that serves as the axle for the idler to spin on. The benefit of this is that the idler actually moves horizontally as you shift up and down on the rear cassette, allowing your chain to stay as straight as possible. Mine seems to catch and not slide smoothly when I shift down really low, but I have only put 13 miles on it so far, so I suspect it needs to be broken in (it may also require a very light greasing, but I won't try that until I have more miles on it). I may check back with another update once I've used it more.

[sgtiger]

Very cool. Thanks for the follow-up. Something to keep in mind when we get Dh's Xtracycle built.