(also posted on Road forum)
I'm 6'6 and 245 and invested in a 64cm 08' Madone 5.1 (with the Shimano 105 11-25 double cassette)last August. Love the bike but have had a major issue and wanted this groups thoughts.
Whenever the largest of the two crank sprockets is engaged with the 4 largest sprockets on the cassette, I get a grinding noise.
My local LBS has bent over backwards trying to resolve. They have adjusted and realligned it on countless occasions, reinstalled the brackets with differant forms of lubricant. All providing short term fixes. Just yesterday, they replaced the frame (courtesy of Trek) with 64" CM 09' Madone 5.5 frame. The aforementioned resolution steps were all based on the shops consultation with Trek.
Here's the kicker....i rode away with the newly framed bike (also,the Shimano components were reinstalled & Cleaned) and the grinding noise was as severe as ever!
My next step is to have the mechanic ride beside me to see if he can visually/audibly determine what's up.
Would anyone have any thoughts as to what the issue might be?
Thanks in advance!