Chain grinding sounds

Chris0099

Hey, Sorry if this is the wrong place to ask but..recently we got our bikes back from a free service from halfords (Yeah i know) Anyway half way home we noticed a sort of grinding sound which we think is coming from the chain rubbing against the front derailleur maybe, not sure if thats what its called? I thought i would post a couple of pics and see if you know how i can adjust it..Basically when i hold the chain away from that metal bit and turn the pedal it sounds fine but when i let it go the grinding sound returns.

http://imageshack.com/a/img924/1759/w8OnvX.jpg

http://imageshack.com/a/img924/2000/j7EOQ5.jpg

cooldad

Looks like the mech needs loosening and rotating slightly but hard to see from the pics.

Read Parktools in my sig and learn to do everything yourself. Much easier.

Or take back to halfords and tell them to do a proper job.

Chris0099

Thanks for the response, I read a little on the parktools, but a lot of it doesnt make a great deal of sense to me as i know very little about mechanics and really just looking for a tighten/loosen this sorta thing rather than how to build and take apart an entire bike.I know its great to know this stuff but i dont really have time right now. I could take it back to halfords but its quite far from where i live so looking for the easiest least time consuming way.

JBA

Look up videos and guides on adjusting front derailleur.
It’s probably one of three things:

High limit screw set incorrectly
Cable tension too high
Derailleur twisted on seat tube.

reformedfatty

Usage of some gears ie smallest cog on the front, smallest on the rear can also cause this, google cross chaining for a bit of background on that

larkim

Chris0099 wrote:

Hey, Sorry if this is the wrong place to ask but..recently we got our bikes back from a free service from halfords (Yeah i know) Anyway half way home we noticed a sort of grinding sound which we think is coming from the chain rubbing against the front derailleur maybe, not sure if thats what its called? I thought i would post a couple of pics and see if you know how i can adjust it..Basically when i hold the chain away from that metal bit and turn the pedal it sounds fine but when i let it go the grinding sound returns.

http://imageshack.com/a/img924/1759/w8OnvX.jpg

http://imageshack.com/a/img924/2000/j7EOQ5.jpg

On the basis that they were like this (in terms of the new noise) when you got them back from Halfords, presumably the first port of call would be to take them back to Halfords? Particularly if you aren't keen on trying your hand at following the guides that others have referred you to (perfectly understandable, if you don't feel at all mechanically minded).

The only thing other than poor workmanship from Halfords which should have addressed the points that others have raised is that final point about not being in large up front, small at the back, or vice versa, as it isn't always possible to eliminate some front derailleur rub when in those combinations, AND they are not recommended combinations anyway as they put the chain under too much sideways stress.

Chris0099

Thanks again you for the responses. I will look into the ''cross chaining'' before i try halfords again.

milemuncher1

The chain is rubbing on the inside of the front mech. There will be a tension adjuster on the gear cable for the front shifter. Turn it anti clockwise, then change down to the little chain ring and back up to the big chain ring, repeat until the chain is away from the mech. Change all the way up and down the cassette, and check the chain doesn’t make contact with the front mech in any gear. You may find that the front mech will start to touch the chain again whilst riding, and changing gears ( especially if you’ve had the gear cables replaced ) as they can take a few shifts for everything to bed in, and settle into position. You can adjust the position of the front mech, using the cable tension adjuster, whilst on the move. Wind it clockwise ( if vertically positioned in the cable ), or backwards if it’s horizontally positioned, to move the mech outwards ( away from the frame ) or anti clockwise / forwards, to move it closer to the frame ( inwards ). If you need a mnemonic to remember which way is which, think ‘Clock out’ or ‘back out’.