I just got a new QR tri-bike with complete Dura Ace drivetrain. I noticed that there are lots of vibrating/rough noise from the drivetrain when going to the top 3 gears due to the chain alignment from the Big Ring (53) and 3 smallest rear cogs(11, 12, 13). The rough noise and vibration is really noticable on the big ring and smallest rear cog. With the chain at an angle, this is causes the bottom pulley to rub against the side of the chain as it gets fed into the rear, the loudest noise source. The bike shifts great, no bent derailleur hanger, no gear slipping, no rubbing on derailleur cages, no loose fasteners….just noise you get from having your chain at the 11 o-clock while everything else is facing 12 o'clock. It is MUCH quieter when in the middle gears.
Do many of you also have this? Bike shops have said that the short chain stays on tri bikes make the angles more exaggerated. This is my first high end bike with a double. Anyways, just wanted to see if this is "normal" with many of you out there. Thanks in advance for any input.