Friday, May 3, 2013

Chain Line

I've messed around with the chain line on my Expedition and 700 long enough to know what I like. The driving reason for eliminating as much tube as possible is the ease of repair. Chain repair or replacement doesn't happen often but when it does the tubes make working with the chain a bear. Once I had a chain break while on a ride, threading the chain back through the tubes while swearing at the sun beating on my head was a dirty and tedious affair. I find it easier to repair, clean and inspect the chain without the tubes in the way. Under normal sober riding conditions I never get tagged by grease.

Expedition
I put a patch of tough rubber self adhering tread material on top of the crossbar to protect against chain slap.  When under tension the drive chain has plenty of room.

I added a Terracycle return idler. A portion of bottom tube is necessary to guide the return chain under the crossbar. I attach the tube to the crossbar with two DiNotte large O rings and a zip tie. The other two lines seen along the crossbar are part of my electronics.

700
On my 700 I removed the top chain tube and left the return chain configuration unchanged. 

Unlike my Expedition there is no return idler just the lower tube attached to the power idler...don't want the extra ounces of a return idler. 

5 comments:

  1. "Under normal sober riding conditions"? Hah! You often get out "in your cups"? Nice job on the chain line. I'm struggling with a nagging sound, which I think is in the power idler. I was able to hear the squeak and put my finger on the idler stud while pedaling, and I felt a pronounced vibration. The other issue is that our chains have finally "stretched," so I've got to replace them, probably the cassettes, too, I supposed. Maybe it's time to get them cleaned up and on the market? I don't know HOW I can really justify the expense of a couple of suspended Scorpions for me and Jodi. I mean, we don't NEED them, but you know the bent disease. Oh, well. So today I'm doing a couple of rides, one on the trike with Django to the nearby organic farm for supplies; the other ride will be with my Haluzak and Burley trailer for a beer run. Too fun. Although I'm trying to eliminate a squeak with the Burley, too. Ever since they went with the square tubing, the noise has been an issue. I'm a bit anal about noises other than standard stuff like clicking of Frog pedals or the quiet rumble through chain tubes and such. Arrrrgh.

    Be well and ride on.

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    1. For purely selfish reasons I hope you buy a Scorpion so I can see how you set it up and get your feedback. But don't let me pressure you...to much. :)

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  2. So here's a question/challenge: A couple months ago I picked up my first Catrike, a 700, which I absolutely love. I have some problematic undiagnosed (really, I'm seen oodles of specialists) neumuscular ataxia, so, with declining balance, the upright was sold after I test road a recumbent trike for the first time. My pedaling can be spastic at times (uneven, not smooth) and it this makes me feel like I have far too much slack in the chain. I have the catrike chain tensioner installed already and wondering if there's any adjustment in that or if some setup of extra idlers can help keep the chain from jumping so much with my uneven pedaling?

    Thanks for your blog, I've very much enjoyed reading through!

    ~Kipp

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  3. Kipp, The slack you refer to is recumbent chain "slap". With 3 times more chain then a traditional bike you're going to experience some chain slap under certain riding conditions. The smoother you pedal the less slap. It's just the nature of the beast and generally nothing to worry about if your trike is tuned properly. It takes a few months to develop your recumbent muscle. The more you ride the faster you'll compensate for any difficulties you may currently have achieving a smooth cadence.
    Enjoy the 700 it's an awesome ride. Thanks for reading my blog. Ride on!!!!

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  4. Mark, thank you for the reply. I'll have to play with it some more, but while on the trainer in the garage last night, I put a little shim between the frame and the chain tube (power - so top tube) and it seemed to remove more of the "slap". I'll have to look for a bit of foam perhaps to make things a little better, possibly a power idler in that position might help. I've absolutely noticed a difference from the first ride, still getting the 'bent legs in shape however. The smoothness of my pedal is something that may always be a bit "abnormal"!

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