A couple months ago I bought a 2005 Lemond Buenos Aires. It has the following specs - Front Derr, rear cassette & shifters: Campy Veloce 10, Rear Derr: Campy Centaur 10, chain: Campy 10, Cranks: Bontrager Racelite Pipe 52/42/30, BB Truvativ GXP Pipe.
A few miles after I began riding it I noticed that if I'm in the middle chainring and the 1-2-3 smallest rear cogs, the chain kind of slips between the middle and large chainring, so I end up pedaling air. I don't have a problem on the big chainring, as I can run all 10 rear cogs (not that I normally do that), and I don't have a problem on the granny chainring either. After about 100 miles I took it to the bike shop (Hudson Trails), and the mechanic said they've seen problems with this crankset, and the changed either the crankset, or the middle chainring (I am not sure). So I got back on the bike, but the problem is still there. I now have about 180 miles on the bike, and I'm getting ready to take it back to HTO.
Before going back I wanted to get some insight/advice so I could discuss the problem with the mechanic, so I called Lemond Bikes. This is what Josh at Lemond said: The tolerances on these 30 speed bikes is so tight that this is a common problem. The chain is thin and brand new cranks have sharp teeth, so when there is cross chaining, the chain won't stay on the ring and gets thrown off caught in between. The solution is to avoid this gear combination. As a matter of fact, with 30 speeds I should only run the middle chainring with cogs 4-7 or so, the large ring with cogs 1-5 and the small ring with cogs 6-10. After 600 miles or so, the teeth in the cranks will wear down a little and then all the problem will go away. He suggested that I could also try lightly filing down the teeth in the chainring to accelerate the process. He said this is a problem with all 30 speed drivetrains, whether it's shimano, campy, or any combination.
This sounds like a bunch of hoey to me. I know what cross chaining is, and I don't consider middle ring and 3rd smalles cog as crosschaining. I'd appreciate any advice the forum gurus, or anyone else with similar problems, can give me on which direction to go. Is it true that 30 speeds have this inherent problem? Is there a more credible explanation to the shifting problem?