worn chainrings question
 

Hello mates
I have a miche team triple chainset with aluminium chainrings ive recently installed a new chain after about 1500km the bike is second hand and ive done about 1000 km myself with stock chain, the wear was past the limit i think according to Sheldon B. New chain is campagnolo record and its not skipping any spockets by now but makes some cracking sounds when under tension to middle and lower chainrings which they seem medium wear or more for the lower, the outer is not.

Now what i was thinking. Ive tried to swap sides to middle and lower ones but i saw it has a some space around the fixing bolt so it gets inside of the chainring and when swapped the chain touches by little the five bolts.
Can i do anything like drill some space with a dremel around the hole from the other side? Is the ring enough thick? Or i should not bother for now? But the worn rings wont they wear the new chain?
I also can see the chain gets lifted a little when loaded which does not happen whe swapped.
Would like some oppinions, thanks.
http://i189.photobucket.com/albums/z...5_221103_1.jpghttp://i189.photobucket.com/albums/z...215_221224.jpg

The rings look fine, but there may be clearance issues. Before taking anything apart, use a dry marker, paint or nail polish to color suspected points of contact, mainly the 5 chainring nuts, and the pick up pins on the outer and middle rings. Ride around a while on the middle chainring, listening for the sound then shift to the inner and repeat, but DO not upshift. As you do this test, use various rear sprockets, and try to note a pattern (if any) of the sound being better or worse depending on which rear sprocket.

Then stop and look to see if the color was buffed off anything, and where. If it was the pickup pin as I suspect, it's fairly normal when riding the inner rings with outer rear sprockets. If it was the chainring bolts. you have a choice. You can consider swapping to a thinner chain, or carefully file the nuts a hair thinner to see if that solves it, or use shims between the ring and crank arm spider to slightly (start at 1/2mm). Note that if you add spacers for the middle ring, you'll also need to add spacers, probably thicker for the inner.

But as I said, first find the exact problem, then consider the options.

Thanks for the fast reply ill do as suggested then and test for clearance issues.