New answers tagged

1

I would start with the QR skewers and dropouts as it's the easiest to fix. I personally had this problem whenever I apply huge force on the pedal (e.g. standing up pedaling) and thought it was the BB but it turned out to be paint flaking off the dropout. Greasing them helped quietened the bike. Also check your chain ring and make sure those bolts are torqued ...


1

I had the same problem. I ended up putting washers at each inner side of the rear wheel skewer and making them really tight because there was movement when going uphill and applying pressure to the rear wheel. Problem fixed!


1

It looks like a bottom bracket problem to be. They cost around $20 so I would replace that and see if it fixes the issue. I had a similar issue and refused to believe that a bottom bracket could go out so quickly so I wasted a bunch of time and stress trying to troubleshoot the issue but when I finally replaced the bottom bracket, it solved my problem and ...


3

TL;DR: re-torque the crank arms to the bottom bearing shaft. Good odds it is the tolerance between the crank arms and the bottom bearing shaft. Until the 80s we used to have a horrible design of a single offset "cotter pin" and nut that would secure the crank arms to the bottom bearing shaft. Example here: https://www.sheldonbrown.com/cotters.html ...


3

Also check for loose spokes, cracked rims, or other wheel issues. A few years back I had an extremely similar knocking I couldn't find for months. The fact that this noise only happens when you're on the bike pedaling means there's some correlation with your weight loading the bicycle and the pressure on the pedals. Those pressures aren't symmetrical, ...


5

Sherlock Holmes said that "when you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth" — and isn't that appropriate given the mystery you present to us? I'll show that after "eliminating all which is impossible" what remains is an issue in the bottom bracket ball bearing/axle or the ...


7

Excluding contact between moving parts, sounds from bicycle are mysterious. They may arise from resonance phenomena (if you have some music expertise, you know, if not it is the same issue that brought the infamous Tacoma Bridge to collapse due to the wind having a certain speed and direction). From this phenomena, there is a rather counter-intuitive ...


9

Great video - we can see that the knock is twice per revolution of the crank, and that its when the cranks are about horizontal. Does it change speed if you change gear? What about if you pedal backward ? If you pedal forward/backward over a small arc of travel rather than doing full revolutions? I suspect that each alternate click is something moving back ...


3

There are several potential sources of noise and vibration in a full suspension bike's rear triangle. Bushing wear in the shock linkages is a big one. My 2002 Stumpjumper had a noise that really bugged me for a time. I even used generous torque on all the linkages before finally realizing after doing some reading that the DU bushings in the eyelets were ...


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