tpolley

i've got a cheapy tandem bike. it has an idler sprocket that puts tension on the chain. anyway, it clicks really loud when we pedal. it has a full range of adjustments, up, down and side to side. i've adjusted it as best i can and its still pretty loud.

is there any way i can make it quieter? would a different sprocket of a different material be any quieter?

i should add that the bike is brand new. it has less than 10 miles on it. it's been too cold to really take it out.

here's what it's doing.

mje

You can see that the sprocket is turning in the video, but its not obvious whether it is turning in sync with the chain. Could the chain be skipping over the sprocket teeth? Maybe the sprocket is too tight and not turning freely.

ksisler

Sounds like it is either too tight or it was never greased. I would bet on both. If that doesn't lead to a cure; If you have some scrap chain rings lying round that are about 10 teeth larger than the timing rings, you can try just taking the idler completely off and try putting a chainring in between the upper and lower path of the timing chain to take up the slack. Listen for noise now. It should have gone aways. If so but the chain is still too loose, choose a slightly bigger chainring. If it looks like you are going to need a really big chainring to make it work, then likely your timing chain is one or more links too long. Try taking out two and see if the chain is now about the right length. Note that you will have to shift one of the cranks up by one link to keep your front and rear cranks in time with each other.

JanMM

Ksisler suggests a 'ghost chainring'. Could work.

Chain idlers are used on most recumbents. These might give you some ideas on a direction to go. https://www.hostelshoppe.com/cgi-bin/...ategory=607300