02-18-2013, 02:59 PM
First thing is to figure out what is "grinding". Is it the chain rubbing on the front derailleur? If so, you may just need a little more shifter adjustment. If the chain is rubbing on the other chainrings, then it might do better with the BB from the donor bike.
On the chainring wobble. It could be that you didn't get the crank seated properly and tight enough on your bike. If it stills wobbles when you put it back, you can also try removing and remounting at 90 degrees change. It could be your BB is bent. A little wobble is not too bad, but if it's enough that it's causing the chain to rub on your front der, then it's probably a problem.
On the chainring wobble. It could be that you didn't get the crank seated properly and tight enough on your bike. If it stills wobbles when you put it back, you can also try removing and remounting at 90 degrees change. It could be your BB is bent. A little wobble is not too bad, but if it's enough that it's causing the chain to rub on your front der, then it's probably a problem.
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