Paul Patzkowsky wrote:
> Yesterday the chain came off my fixed gear bike twice. Once while
>pedaling at a very high cadence and the second time while backpedaling. The
>first time I would have thought that the tension was correct. The crankset
>isn't as concentric as it should be so there is a little slack at one point
>during a revolution. Otherwise it has worked fine on other rides,
> The second time, perhaps chain alignment/tension may not have been
>correct. Field repairs are not usually optimal. What should I watch for in
>correcting this problem?
No field adjustment will have any effect on alignment (chainline) but it is important to get the tension reasonably correct.
I've got a couple of articles you might find helpful.
You'll find a technique for improving the concentricity of your chainring at:
http://sheldonbrown.com/
You would also do well to look over my article on Chainline:
http://sheldonbrown.com/
Sheldon "Coasting Is A Pernicious Habit" Brown
Newtonville, Massachusetts
+-------------------------------------------------------------+
| I still feel that variable gears are only for people over |
| forty-five. Isn't it better to triumph by the strength |
| of your muscles than by the artifice of a derailleur? |
| We are getting soft...As for me, give me a fixed gear! |
| --Henri Desgrange, _L'Equipe_ article of 1902 |
+-------------------------------------------------------------+
--
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