When I pedal hard, I can see the chainring being pulled to left and to the right. The front derailler is set so it has about 2mm of clearance on the outside of the big chainring but it still deflects enough so that the chain rubs against the front derailler when I'm in the either of the two smallest cogs.
Last night when I was cleaning my bike I noticed some frame damage caused by the inner chainring rubbing against the right chainstay. This must have been caused by the same chainring deflection. There is about a 3mm clearance between the inner chainring and the frame.
My bike is a new 63mm Cannondale R2000 with full Ultegra. I have about 1400 miles on it since getting it in the winter. There is no obvious play in cranks. I don't think this problem started until I had a few hunderd miles on the bike but I may be wrong; it may have been there from the start.
So what can the problem be? Is it frame flex or crank flex or is my bottom bracket loose? Please help. Thanks
Originally posted by Bartwick When I pedal hard, I can see the chainring being pulled to left and to the right. The front derailler is set so it has about 2mm of clearance on the outside of the big chainring but it still deflects enough so that the chain rubs against the front derailler when I'm in the either of the two smallest cogs.
Last night when I was cleaning my bike I noticed some frame damage caused by the inner chainring rubbing against the frame. This must have been caused by the same chainring deflection. There is about a 3mm clearance between the inner chainring and the frame.
My bike is a new 63mm Cannondale R2000 with full Ultegra. I have about 1400 miles on it since getting it in the winter. There is no obvious play in cranks. I don't think this problem started until I had a few hunderd miles on the bike but I may be wrong; it may have been there from the start.
So what can the problem be? Is it frame flex or crank flex or is my bottom loose? Please help. Thanks
I don't think normal humans flex the BB on Cdales. Take it back to the dealer.
