Chattering aluminum frame

landdnl

After riding my Cinelli Experience for about 8 months, I finally got the setup right. I'm 50 yrs. old and this is my first road bike. The top tube was a little bit long for me, but I made do until I got the proper sized stem. I started out with a FSA Plasma bar/stem combo which I thought would work since I used a cheap stem and bar with equivalent dimensions to verify fit. What I didn't foresee was that you had to mount the shifters quite low on the FSA. So I was about 10mm shy of being somewhat comfortable on the hoods. Anyways, my bike is setup perfectly now. I raised(substantially) the seatpost(300mm) to where it needed to be and moved the seat all the way forward(I have a 25mm offset seatpost). Here finally is my issue. Before I did my setup the bike was very quiet and smoothe. But since I raised my 300 mm carbon seatpost so the bottom is about 2 to 3 inches below the top tube/seat tube junction, that is when I started getting the chattering over road imperfections and even slightly when I shift. I guess one option is to get a longer seatpost. I don't know if they make them 400mm for a 27.2 diameter or not. I'm not sure 350mm would totally mute it since I raised the seatpost by 70mm. I'd rather have a little more weight than the bike chatter. I'm sort of thinking since I raised the seatpost there is a lot of cosmetic damage, and instead of repainting, just cut it down so when I buy a replacement post, I could drive the old one down close to the bottom bracket before I install the new one. I was even wondering if insulation foam in a spray can that expands would do the trick. Or maybe I should stop typing and one of you would have a better solution. Thanks in advance.

sungod

paragraphs would help :-)

if you're getting noise fron the seat post...

seatposts usually have a minimum insertion mark, that's the first to check, i'd guess yours is ok, if not, get a longer post

in general, the end of the seatpost should extend down the seat tube to below where the underside of the top tube meets the seat tube, which you say yours does, so ok again

remove the post, clean it and the inside of the seat tube thoroughly, then put assembly paste on the post and re-insert, that'll probably eliminate any noises

if it's a really tight fit use the tacx paste, if the post is less tight the finish line paste is a bit chunkier

if you do fit a new post, don't ram the other one down the tube! just remove it

landdnl

Good point. I didn't reapply carbon paste or clean the seat tube out. I'll try that.