Bicycle Mechanics - Noisy chain

I've had my new bike for about a week, a Specialized Hardrock Pro. Since my first ride I've noticed that when I coast through turns my chain makes a lot of noise, like a scraping sound.

What causes this sound, and can it be fixed?


Thanks!

Are you sure it is your chain?

When you coast your chain does not move, so it shouldn't be able to make noise.

Is it clanging against the derr. cage????

Originally posted by captsven
Are you sure it is your chain?

When you coast your chain does not move, so it shouldn't be able to make noise. Good point.

No, I'm not sure it's the chain. And come to think of it...

OK, I just lifted the back tire off the ground and gave the pedals a spin. Apparently the noise only happens when the tire is making contact with the ground. The tire isn't loose so I can't tell what is making contact. It only happens on turns...weird.

maybe I'll take it back to the LBS tonight and see if they can check it. I only got it last week, and since it was pouring rain when i bpught it, I couldn't take it for a test run. :(

jest spray som wd-40 on it

Originally posted by L Lortami
jest spray som wd-40 on it

:rolleyes:
What are you talking about? You do not spray WD 40 on anything having to do with the bike.

Mightypudge,
The side knobs on your tire are gripping the pavement and flexing causing the sound. That is MHO. Try airing the tires up to about 55 lbs. for pavement and then reduce it to 45 for dirt.

Originally posted by Hunter
Mightypudge,
The side knobs on your tire are gripping the pavement and flexing causing the sound. That is MHO. Try airing the tires up to about 55 lbs. for pavement and then reduce it to 45 for dirt. I thought that too, but the sound is awfully "metallic" if you know what I mean.

Still, it's worth a shot. My tires are up around 65 right now because I've been sticking to pavement. So for tomorrow's ride I'll try 55 and see what that does.

Thanks!

OK, I tried letting riding at a lower tire pressure and no dice - The sound is still there. This is a definite metal scraping sound and it is more noticeable at higher speeds. When I put the bike on the stand the sound goes away, but I do not think the sound is the tires. I can hear the tire sound and this is much different.

OK, I solved the mystery noise. It was my rear wheel flexing on turns and my rotor was rubbing against the inside disc brake pad. I took it back to the LBS where I bought the bike a week ago and they fixed it.

While I was there they also "fixed" a few other things.

-- My front wheel was out of true. I noticed this on day one but wasn't sure I was right.

-- My front derailleur was sitting too close to the chain.

-- The rear brake housing is a) too long, and b) not secured to the frame properly.

I don't think I'm buying my next bike at this place.