bagel007

Might grinding sound be a sign of stretched-out chain? Especially when in low gear and climbing?

How do I measure if the chain is stretched out?

It's Giant Cypress 2009. The first time I had to replace the chain was after barelly 300 miles after purchasing the bike (new one). Today I have on it over 1,300 miles.

Thanks!

JohnDThompson 

A grinding sound indicates a dirty drivechain -- chain, chainrings, and/or cluster -- and will be present in all gears. A worn chain will not seat properly on the cogs (particularly the smallest cogs and under high pedal force) and will sound much like trying to change gears.

ClarkinHawaii

Why did you replace the first chain after only 300 miles? This is highly unusual and should be a red flag.
Since you mention it here, I'm assuming it was because you felt it was worn out.
If you don't know how to determine whether a chain is worn/stretched out, how did you know to replace it?

bagel007

Not me. It was the bike shop that I purchased the bike from. They decided that the chain is stretched out and replaced it.

ClarkinHawaii

OK, well, if the bike was new as you indicated, in my experience there is no way under normal circumstances that a chain could be worn out after 300 miles. You might want to ask the lbs about that. In fact, you should have asked them at the time, since if no cause for the premature wear was noted and corrected, it would be reasonable to expect that you would continue to replace the chain every 300 miles. Maybe they slipped a used chain on the bike temporarily when you initially picked it up because they were out of new ones or something; and expected to replace it for you after they got some more new chains in. Did they charge you for the 300-mile replacement chain, or was it free?

In any case the answer to your question is that you can measure the chain against a good metal ruler. Search under "chain" at Sheldonbrown.com. An alternative is to purchase a little handy-dandy gauge for chain measuring like the Park CC-2. The measuring tool doesn't do anything for you that a ruler wouldn't do, except that it's easier to use with the chain on the bike and I didn't happen to have a good metal ruler so I said what the hell . . .

davidad

24 links of chain are 12" center to center on the rivets. You should replace at 12-1/6" wear (or streach). Here's the info from Jobst Brandt on chain maintaince. https://draco.acs.uci.edu/rbfaq/FAQ/8d.2.html
I follow the advice and regullarly get over 8000 miles on my seven and eight speed chains. The cassettes last two or three times longer.

bagel007

OK, I've measured the chain length with a metal ruler. Instead of 24 links, I measured 12 links and it seems to be perfect.

Still, something is wrong either with the chain or the whole drivetrain. More than the sound, it is the feeling of some kind of vibration that is coming from the pedals. It bothers me particulary when climbing. I have the impression that I'm struggling with some extra force besides the hill. But the vibration (when pedaling) is also noticeable on flat terrain.

I think I'll bring the bike to the nearest bike shop for tune-up.

bagel007

They didn't have the bike in the store, so they ordered and assembled it for me. I don't know if the chain was new or not.

And yes, they were surprised that the chain was worned out in such short time. I didn't get any explanation from them why it could have happened.

No, didn't charge me for the new chain; they replaced it for free.

ClarkinHawaii

Now it sounds like your derailleur is out of adjustment (either front or rear or both) and the chain is not seating itself squarely on each sprocket, but rather rubbing against the sides of the next sprocket. This is an easy thing to adjust; and you really need to know how to do it, if you are going to ride at all. Sheldon makes it simple:

https://sheldonbrown.com/derailer-adjustment.html

ClarkinHawaii

I neglected to mention: You need to pay careful attention to which gears you are in when you get the grinding noise. This will help diagnose what's causing it. Also you need to avoid "cross chaining" like when you are in the biggest chainring (front) and the biggest sprocket (back) this causes a big angle in the chainline which causes rubbing. Check it out and tell us what gears are troublesome.

bagel007

I'm almost exclusively using the middle chainring. The grinding noise (or rather the metal-on-metal "feeling" that gets to me through the pedals) happens after I downshift in the rear into the 4th, 3rd and 2nd gear.

BTW, since I purchased the bike I'm having this sound in the 5th and 4th gear: https://www.youtube.com/watch?v=NK7V5dTnUoA . I went to the shop I bought the bike from. The mechanics worked for some two hours on the bike. They opened the BB, replaced the pedals. What not. Nothing helped. Then came in the "technical manager" and told the guys that the chain is worned out. So they replaced the chain. Once again, no change. The sound was (and is) there only when riding the bike and only when pedaling. You cannot hear it when it's on the work-stand. At the end the technical manager finaly said that he thinks he has the solution. He worked on the hub from what I saw. I took the bike for a spin. It worked -- no more clicking sound! I was in the shop already more than 3 hours and was glad it's over. I took the bike for a couple of rides and guess what -- the sound returned. I went to the shop and I saw that they had me enough. They suddenly wanted me to schedule an appointment for everything. I decided that's it and never returned to that shop. Simply put, I didn't have "luck" with them. That's why I want to go to a different shop and ask see if they can do anything about that sound and other things, like the grinding sound/feel in the lower gears.

ClarkinHawaii

If the bike has grip-shift , it's possible that when you are riding, you inadvertently twist the shifter just a tiny bit (that you'd swear you're not) and it's enough to move the rear derail a tiny bit and cause rubbing/clicking vibrations. This is why it doesn't happen on the workstand.

Beyond that, your problem is that the chain is rubbing on something. Your task is to locate the rubbing point. Until you know what's rubbing what, it's impossible to tell you how to fix it. Chain could be too loose, rear derail pulleys could be in contact with the sprockets, any number of other possibilities. I bought a workstand and set it up in the house, put the bike on it and fiddled around with it to my heart's content. The Sheldonbrown site has all the info you need. To be really happy, I liberated myself from being at the mercy of other mechanic's mistakes. If they can do it, so can I and so can you. Declare your Independence and become self-reliant.

ClarkinHawaii

OK, that's what you should do--but if it's too ambitious for the moment and you just want to get the #### bike on the road and have some fun with it, find out for sure where the chain is making unauthorized contact and we can tell you how to fix it!

60bass

I had the almost the same exact noise on the Trek Navigator I owned. It was fine on the stand, but the minute I hopped on it started to make the noise. It drove me nuts trying to figure it out. When I did find the problem it was so simple I had to laugh.

Turned out all that was wrong was the rear wheel skewer wasn't tight enough. With no weight on the bike the wheel felt tight with no play, but when I rode it the weight caused the wheel to move around just enough to make a click sound from the rear cogs in certain gears. My Nephew noticed the wheel was moving slightly when he was riding next to me and he could see a small hitch in the chain where it was catching on the cog.

Rode home, pulled the skewer, cleaned it, reinstalled, and made sure it was nice and tight. No more clicking.

Might be worth checking. Sometimes we overlook the simple stuff.