dstamat

Hello All,

I have owned my Nexus 3-speed hub equipped bicycle for 5 years now. The gearing was pretty high (38 front, 16 rear) so I have barely used the 3rd gear.

A week ago I changed the rear sprocket to a 20-tooth sprocket so that the gearing is lowered by 25% (I do all the work on my bike myself) and now I can use all gears easily. The problem is that on the 3rd gear, and after a few rotations, a very loud knocking noise starts coming from the hub. It is very noticeable and I need to change back to 2nd. I do not notice any excessive friction however and there is no such problem in 1st or 2nd gear.

Any ideas what may be going wrong?

Thank you in advance

Dimitris

reptilezs

is the shifter adjusted correctly?

dstamat

reptilezs,

Very good tip. I loosened the shifter cable a bit and now the noise is gone. Problem solved!

Many thanks

Dimitris

Dan Burkhart 

Ensure the alignment mark is centred between the two lines in the window of the bell crank housing when the shifter is in second gear position, and after you have ensured that second gear is engaged by turning the crank. That is how you check for proper adjustment.
If you have the old style with an exposed bell crank, there is a hole in the crank that aligns with a mark on the housing beneath in second gear.