Oct 23, 2001 8:04 AM
|I was thinking about converting an old Cannondale bone shaker that resides in my garage to a fixed gear for winter training but my LBS said that since it had vertical dropouts, it wouldn't work without some little device that allows chain tensioning. Does anybody know what this device is called, if it works, and where I can get it. My LBS looked around in some catalogues for awhile but couldn't find anything.
|re: Fixed gear||alexfr99|
Oct 23, 2001 10:46 AM
|I think you can do it w/o a chain tensioner. Check out this website http://www.peak.org/~fixin/ This guy has a "calculator" that allows you to figure the exact cog-chainwheel combo for your chainstay length. I have done several fixed gear bikes. Feel free to contact me at firstname.lastname@example.org and I'd be happy to answer questions or just walk you through....see ya.|
|The chain tensioner is called...||Rusty McNasty|
Oct 23, 2001 11:41 AM
|...a CHAIN TENSIONER!!!!
If your LBS can't find one, then change shops. Tektro makes them, Surly has them, Harris Cyclery has them, every recumbent has them, even Nashbar has them!
Your LBS sounds like a loser-find a better one.
Oct 23, 2001 4:33 PM
|a fixed gear will rip the tensioner right off your frame. a singlespeed freewheel works with it, but they aren't designed to work with the stresses put on a fixed system. you could try it, but you'd probably be throwing away the money.....
Oct 23, 2001 6:19 PM
|I shouldn't have called it a "chain tensioner", my LBS said the same thing. They thought they had seen a device that would allow me some slight adjustment for a vertical dropout. I think I found it at the site Alex posted. BTW, Rusty, this particular LBS is far and away the best around, and they did know what a chain tensioner was, just couldn't find what I needed for my application. Thanks all,
Oct 24, 2001 1:51 AM
|There is a fixed tensioner. It's a "H" shape that bolts on to the top (or bottom I suppose) of the chain stay, and has a fixed (as opposed to the spring loaded ones like the "singulator" etc) but adjustable jockey wheel that takes up and slack in the chain - like a cam chain tensioner on some car sustems. Being fixed rather than sprung, you can use it with a fixie, as the force of the chain is taken directly onto the chainstay. I don't know who makes them, but there is a guy I ride with who has one on his winter beater with verticle drops - weird, but it works - he has a double on the front, and uses the tensioner to adjust between the two - takes him 10 seconds at the top/bottom of a hill. Next time I see him I'll ask where he got it.|
Oct 24, 2001 5:38 AM
|Please do, that might be the "thing a ma bob" (highly technical bicycle term) that my LBS was trying to find. I still have some question as to whether it will hold up while pedaling backwards, has your friend had any problems in this area?|
Oct 24, 2001 5:51 AM
|If this tension adjuster aligns directly over (or ideally under) the chainstay, it could work when applying backpressure to the pedals. If it has an offset, I would think it would rotate around the chainstay if too much force were applied, as in trying to backpedal. Of course, you now have the consideration that you are going to be putting this on a C'dale, fairly light gage aluminum. Will the chainstay handle the force from a chain tension adjuster at mid-stay? Just something to consider.|
Oct 24, 2001 6:43 AM
Honestly....i would try to do it w/o the chain tensioner deal. I've had friends who have used them and they don't always work so well. It really requires you micro-tune your chain alignment which is sometimes problematic. (Your cannondale is probably a 126mm or 130mm rear and depending upon the wheels you run, chain alignment will take some trial and error time. I have found that older campy nr and dura ace hubs are the easiest to work with unless you want to invest in a flip- flop or track hub) Figure out what size gear you want to run and then work through the chainring/cog combo that will get you closest for your particular chain stay length. My guess is that you will be happier with a straight fixed set up w/o having the added hassle of a tension device. PLus, you will end up spending far less money in the long run....good luck in any event
|My SO has an '87 Cannondale he did this with...||lonefrontranger|
Oct 25, 2001 6:57 PM
|It too has vertical dropouts. It's one of the old criterium frames.
He put on a "Single-ator" (unknown who the mfg. is) and runs a 7-speed, usually in the 16, although he initially ran the 17. Dunno about the chainline issues. He uses this as his commuter with flat pedals, so he wasn't all that interested in a fixed.