Chainline mechanics/physics
08-22-07, 07:57 PM
#1
Disraeli Gears
Thread Starter
Chainline mechanics/physics
I don't understand why it's so important for a fixed/singlespeed to have cogs inline, and it matters not so much on geared bikes. Obviously, the derailer can help guide the chain onto the correct cog, and keep it there, but the drive sides of front and rear cogs, under a lot of tension, are seriously out of line when the pairing is not optimum -- so why doesn't the chain derail then? Is it the loose side where the chain problems occur on a singlespeed (where the chain catches a plate on a cog tooth)?
Thanks,
Thanks,
08-22-07, 08:34 PM
#2
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I don't understand why it's so important for a fixed/singlespeed to have cogs inline, and it matters not so much on geared bikes. Obviously, the derailer can help guide the chain onto the correct cog, and keep it there, but the drive sides of front and rear cogs, under a lot of tension, are seriously out of line when the pairing is not optimum -- so why doesn't the chain derail then? Is it the loose side where the chain problems occur on a singlespeed (where the chain catches a plate on a cog tooth)?
Thanks,
Thanks,
I have found that when the chainline is not right, it becomes very hard to shift into one of the extremes, and the chain often will not stay there. The system designers at Campy and Shimano did know what they were doing.
I'd think for a single/single that if the chain is out of line enough, there will be more friction, noise, and perhaps even chain jumping.
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