Chain keeps popping of?

[WEAKFISH]

I put together using a 40s Cleveland Welding frame. I used new wheels and a 1/2 inch pitch sprocket (not skiptooth). The crank can turn several tims before the chain gets slightly off track, causig it to get real tight then popping off. Not sure if this is a result of using the wrong chain or if the sprockets are out of line. Can anyone help?

 

[Anonymous]

Sight down at the back of the bike at the chain line.

You may have to space either the front or rear sprocket to get it in line.

 

[Anonymous]

Is EVERY link of the chain free and not bound up or kinked?

 

[gcrank1]

If you have, or have access to a small laser level you may be able to set it on the chainring and use the red dot to see how the alignment is at the rear. Just remember to compensate for the height the laser sits above the chainring.

 

[Anonymous]

A Laser?

Hold it half cocked and the chain will apear straight.

A yardstick laid on top of the chain will give you a better idea.

 

[WEAKFISH]

the chain is new so I know the links are free. I think the inside nut on the back wheel is too thick.How would I put a spacer on the crank sprocket?

 

[gcrank1]

You would set the laser on the face of the chainring, or whatever surface you 'true to', not try to hold it at the teeth to get a straight line. By setting up an index surface you can use them to check frames and all kinds of things.
A taut string works too, Ive found it hard to get a yardstick into the backend.

 

[Anonymous]

Is the front sprocket bent?

Are the teeth worn too low?

Im grasping at straws here...Got a pic of the problem?

 

[WEAKFISH]

I put a thick washer on the inside of the front sprocket under the race nut as a spacer and it solved the problem. Thanks guys.

 

[Anonymous]

We are here to help.

Good Deal on finding/solving the problem.

 

[WEAKFISH]

We are here to help.

Good Deal on finding/solving the problem.

You guys are great here...saved me a trip to the LBS!!

 

[Anonymous]

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