Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at email@example.com.
Question: I’ve have a Dura Ace 9000 group set with an Ultegra cassette and Rotor cranks. Whenever I’m in the third cog from the bottom, there’s a constant clicking noise. It does not click in any other gear. I put another Ultegra cassette on and it does the same thing and it also does it on my Wahoo Kicker trainer (105 cassette). I’ve released the cable to make sure the bottom limit was aligned and it was perfect. The clicking is always in the same cog. I’m thinking it has to be the derailleur. Thoughts? Have you heard of this before with the DA 9000?
If I over tension it so that is barely shifts down, it will go away, but that’s not a good option. Any assistance you could provide would be greatly appreciated. From: Ryan
Answer: You have an unusual problem. Where I am confused is that you have the same problem on the 105 cassette that you have on your trainer. Because the 105 cassette is a 10-speed unit, it makes me wonder if you have the right cassette for your 9000 11-speed group?
Assuming you have the right cassette, have you experimented with adjusting the b-tension screw on the derailleur? The type of problem you are experiencing is usually cured this way. I haven’t heard of this exact problem before with 11-speed groups, but I was able to recreate it here in the shop. With a combination of retuning the b-tension screw and the cable tension, I was able to silence the click, so I would give that a shot.
It is also good to double check that you have the cable anchored on the correct side of the anchor bolt on the rear derailleur. Check the pulley bolts to make sure they are torqued and that the pulleys are installed correctly. I would also check the derailleur hanger for proper alignment.
Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.