FRAME CLICKS, CREAKS, AND KNOCKS – A DEEPER DIVE:

   Higher technology frames and parts, most notably the carbon versions, must be correctly lubed, installed and tightened, or noises may well erupt.
    Frustratingly, if your bike is making a noise, it almost always sounds like it is coming from the crankset. Something as far away as a spoke in the front wheel - or the derailleur hanger in the back - not being tight, can result in a click or knock that sounds all the world like it is coming from the crankset, or what we call the “bottom bracket”. The reason that we hear the noise coming from there is both a function of acoustics, and of our perceptions.
     The harmonics of frames is a result of several tubes coming together at the bottom of the frame. That portion of the frame can amplify a noise from somewhere else on the frame such that it sounds like the noise is originating from down there. Carbon fiber frames are constructed with strands of carbon which are put under tension. That tension structure carries noise very effectively down to the bottom bracket area and amplifies the noise. If you want a good example of how a tension structure amplifies and carries sound, simply pluck a spoke on one of your wheels. You should hear the spoke, and wheel, “sing” (if you don’t, your wheel needs to be tensioned!)
      The other part of this process that tricks us is that most clicks and knocks occur under load. Load is maximized when we are pushing down on the pedals. Our brain associates the noise with our pushing on the pedals, and tells us the noise is coming from the pedal/crank area. In reality, a loose stem bolt, for example, can cause a creak that manifests only when we are pushing on the pedals.
     Hear is a list, in approximate order, of the sources of knocks, creaks, clicks and “bottom bracket” noise:

• Loose crank arm
• Loose wheel skewer or thru-axle
• Loose seat clamp
• Loose seat post clamp
• Loose stem bolt(s) – bar or steer tube
• Loose headset
• Loose bottom bracket
• Loose pedals or pedal bearings or noisy shoe cleat
• Loose derailleur hanger bolt
• Loose chainring bolt(s)
• Loose seat rails
• Cracked frame
• Loose spoke(s)

 
       Many of these things can be checked fairly easily and quickly. Some of them, however, can take quite a bit of time to work through.