Here is the photo of my sprocket. After adjusting the chain slack and axle, I can still hear a bit of grinding sound. Maybe because the chain is hitting the outer side of the sprocket (you can see the smooth sides of sprocket teeth). It appears to be a bit loose but I have no idea how to tighten those bolts. I mean do i tighten the 2 bolts on the side or do I need a special tool for the center thing. Please help.

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  • is your chain correctly aligned? - can you take a picture from the rear of the bike showing the length of the drive chain. The middle part is the drive from the gearbox and cannot be tightened, the two outer bolts should already be tight and are the ones that hold your sprocket on to the drive shaft.
    – Mauro
    Aug 10, 2016 at 10:04
  • @Mauro Thanks for replying and the info. Id have to get back with the pic tomorrow as its already night here. Is it normal that the sprocket wiggles a bit?
    – bikernix
    Aug 10, 2016 at 10:09
  • 3
    On my bikes yes, this allows for imperfections with the chain or movement due to torque etc. Add the model of your bike and year so we can look up any manuals about it too.
    – Mauro
    Aug 10, 2016 at 10:22
  • Honestly, I don't how you would know anything is wrong with that sprocket specifically without knowing what is causing the grinding noise. The sprocket looks normal to me. The teeth wear like that normally from the chain passing over it. Why do you believe it is this sprocket causing the noise?
    – CharlieRB
    Aug 11, 2016 at 20:35

1 Answer 1


You cannot actually tighten it to the shaft, those 2 bolts just hold the retainer plate, this is all that keeps the sprocket from coming off. Once the plate is removed you can slide the sprocket off of the output shaft.

Sprocket and output shaft are machined for a tight slip fit, so if there is play either the sprocket is worn, the output shaft is worn or both. Remove the Sprocket and inspect for wear, replace worn part(s).

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