Grinding sound only when sat down

[k0109671]

Hi there, much appreciated for any help anyone can give me on this.

So I've got a Cannondale Hardtail SL 5 2011 - about a month/half a dozen rides old.

Now what happens is I get a nasty grinding sound at the front cogs/derailleur area. The weird thing is though it only gets really bad when I'm sat down!??

When I'm out the seat you can just about hear it, but its so bad when I'm sat down i can hardly bear it. Needless to say I'm not riding much on it as I'm constantly stood up!

Im not sure how else to describe it, its a proper grinding, nasty, 'chain about to snap' type of noise but it might not be the chain at all. The gears shift without any real problem, if that helps.

I did take it to a different bike shop (my friend put it together as he works at a different shop - he's not around to look at it at the moment), and all this guy said was the perhaps i had some 'play in the lower bracket', whatever that means.

I'll try to give any more info if i can, the sound probably started in just my 2nd ride and has just got progressively worse.

Help! (and thanks!)

[JohnV]

I'm assuming that you purchased the bike on-line or from a department store, correct? Does it do it when you pedal standing up? When your friend put the bike together, did he grease the bottom bracket and the pedals when he put them in? Try cleaning and lubricating your pedals. Let us know how it turns out.

[painkiller]

do you have a suspension seatpost? They can do strange things sometimes

[k0109671]

Thanks guys, really appreciate the help. I ended up biting the bullet and sending it into a shop. It was the seat! The post was touching at the bottom and combined with an accumulation of grit etc (only rode this thing a few times! A bit off road though, possible explanation) it was causing the grinding. Weird though as I could swear blind it was down at the brackets. Anyway he's chopped a bit off the bottom of the post so that it won't happen again.

Thanks again for your help, hopefully someone with the same problem will stumble across this post.

[painkiller]

Ha hah my dear watson. good deal