noise in 17t

[scpknees]

Hello, i have noise only when im in my 17t sprocket, which happens to be the most perfect chain alignment when in my 39 ring. i get this noise whether sitting or out of the saddle. rear wheels were swapped to check for a difference-none. threw the bike in the repair stand to see if i could check the problem,and it wouldn't make the noise. as always with a ti frame it sounds like it's coming from the cranks. i would bet it's not the cranks/bb. if anyone can help i would be very grateful.

thanks much!

[Dave]

I've noticed a litle bit of what I'd call chain rattle only in gear combos that have a nearly perfect chainline. I've decided that the reason is most likely due to the fact that the chain has no side loading with this near-perfect chainline. I've noticed on most of the bikes I've owned over the last 20 years. There was never anything wrong with them.

Some modern ultralight frames (usually aluminum) are great sounding boards, amplifying every small noise.

There's also the possibility of a slight misadjustment to the shift cable tension. The use of a real light weight or dry type chain lube can add to the noise.