Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Expanded or Worn Chain?

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Expanded or Worn Chain?

Old 07-26-20, 07:00 AM
  #1  
tommyd49
Senior Member
Thread Starter
 
Join Date: Aug 2007
Location: Cambridge, UK
Posts: 160
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Expanded or Worn Chain?

Hi everyone

It's been quite a few years since I posted on this forum, so hello again to everyone!

The other day I picked up a steel-framed Raleigh Amazon hardtail. A friend of mine gave it to me - I think someone where he worked had just left it a few years ago, so he picked it up and left it sitting around at his for a while.

One of the main issues is hopefully visible in the two photos I've attached. The rear derailleur seems to be sprung back to its "natural" position, how it would look if disconnected completely from the chain.

The chain is actually on the bottom rear cog and the bottom front cog. Obviously, the rider wouldn't/shouldn't go in to this position much when riding, but I wouldn't expect the rear derailleur to spring back like that when the chain is on. This was the condition I found the bike in.

Shifting to the middle front cog eliminated the problem. It seemed to me that the chain was too slack in the position of the smallest cogs. Maybe the chain is too long - but everything on the bike looks original. I figured the chain might be a bit worn, so I tried the measuring trick - if 12 full links is 12 1/16" or longer, the chain is worn. I only had a 6" ruler to hand, so measured 6 links - which was about 6 1/8". Makes 12 links 12 1/4" - very worn!

It seems strange that the chain could be so worn whilst the cogs all look in good condition.

So, can I ask:
  1. Has anyone seen a chain so worn whilst the cogs are in good condition? Or else has the chain somehow expanded over time, therefore loosing tension?
  2. Does it seem likely that an extra 1/4" or so of slack in the chain would be enough that the rear derailleur would no longer be pulled forward, thereby going back to its "natural" position?
Interested to hear any opinions. Thanks!


tommyd49 is offline  
Old 07-26-20, 08:17 AM
  #2  
WGB
WGB
 
WGB's Avatar
 
Join Date: Jul 2017
Location: Niagara Region
Posts: 1,933

Bikes: League Fuji

Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 566 Post(s)
Liked 119 Times in 89 Posts
Possibly a PO replaced the cassette or even wheel and cassette but not chain?
WGB is online now  
Old 07-26-20, 08:29 AM
  #3  
HillRider
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 32,266

Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!

Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 1443 Post(s)
Likes: 0
Liked 262 Times in 211 Posts
Shift the bike into big-big (largest chainring and largest cog). If it will shift into that gear with slack to spare you can shorten the chain until it just does. However the chain must allow big-big. And no, the chain will not "stretch" enough to go completely slack just from wear.
HillRider is offline  
Likes For HillRider:
Old 07-26-20, 09:43 AM
  #4  
dsbrantjr
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Posts: 7,569

Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta

Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 1158 Post(s)
Liked 549 Times in 396 Posts
Never Fix A Running Piece. If you do not intend to use the small-small combination, and the chain is not actually slack in that combination, what advantage would shortening the badly-worn chain provide? I suspect that if/when you replace the chain you will need to replace your freewheel/cassette as well due to running with such a worn chain, so be prepared for that. At this point you may as well just run the chain-cassette combo into the ground and replace them both when the time comes.
dsbrantjr is offline  
Old 07-26-20, 09:46 AM
  #5  
madpogue 
Senior Member
 
Join Date: Jan 2004
Location: Madison, WI USA
Posts: 5,057
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
Quoted: 1616 Post(s)
Liked 672 Times in 514 Posts
Have you measured the chain for wear?

Is the wheel all the way back in the dropouts?
madpogue is offline  
Likes For madpogue:
Old 07-28-20, 11:52 AM
  #6  
tommyd49
Senior Member
Thread Starter
 
Join Date: Aug 2007
Location: Cambridge, UK
Posts: 160
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I've had another look and yes, the wheel is well back in the dropouts.

I also measured the chain for wear again and 12 full links of the chain measures 12 1/8". I measured with a digital calliper this time - used a ruler before which was a bit bent.

I put the chain in the big-big combination and measured for slack by pulling together with a couple of small screwdrivers. There was an inch and a half of slack - i.e. one and a half links. Considering 1/8" of wear over 12", doing the maths - an extra 1/2" over the whole length of the chain due to wear makes sense.

Originally Posted by dsbrantjr View Post
Never Fix A Running Piece. If you do not intend to use the small-small combination, and the chain is not actually slack in that combination, what advantage would shortening the badly-worn chain provide?
I mostly agree with this, but still could accidentally shift in to the position. If this happens it would be a problem, because there is so much slack in the chain that the upper pulley in the RD comes in to contact with the chain and they start grinding together.

So, I've two options:
  1. Buy and fit a new chain and hope the front cogs and cassette are OK
  2. Leave it alone and make sure to avoid shifting in to that combination.
2 certainly seems appealing. My only thought for 1 is that the cassette and front cogs don't look worn - not shaved teeth etc.
tommyd49 is offline  
Old 07-28-20, 12:10 PM
  #7  
phughes
Senior Member
 
phughes's Avatar
 
Join Date: Mar 2011
Posts: 1,707
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 446 Post(s)
Liked 236 Times in 152 Posts
The bike has a tripple, it is not intended to be used on the small ring up front and the small cog in the back. Get it out oif the small ring up front and it should be fine.
phughes is offline  
Old 07-28-20, 12:19 PM
  #8  
ClydeClydeson
Senior Member
 
Join Date: Mar 2019
Posts: 186
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 53 Post(s)
Liked 57 Times in 43 Posts
1/8" of wear over 12" will almost certainly cause the chain to not mesh well with the cogs. Changing the chain would be a mistake and almost certainly make the drivetrain skip under pedalling load.

Also, there is no damage caused by running a slightly long chai, even if it's dragging over the derailleur jockey wheels or front derailleur cage - unless you ride like that for a long long long time. When I used to assemble bikes I would adjust the limit screws on the front derailleur so it made a bit of noise when cross chaining (either big-big or small-small) as a kind of 'alarm' that you were in a bad gear. If the chain on your bike makes noise when in small-small, just treat it as a reminder not to cross chain.
ClydeClydeson is online now  
Old 07-28-20, 12:28 PM
  #9  
Litespud
Senior Member
 
Join Date: Oct 2017
Location: Chapel Hill NC
Posts: 928

Bikes: 2000 Litespeed Vortex Chorus 10, 1995 DeBernardi Cromor S/S, Nashbar 3sp commuter

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 356 Post(s)
Liked 321 Times in 181 Posts
If the chain is still under tension in the small/small combination, and the long lower stretch isn't rubbing against the chain wrapping around the upper jockey wheel, then you're all good - this is as slack as it's going to get, and as others have said, you're not likely to be using this chainring-sprocket combination in the wild. But if you're concerned, you could likely remove a link or two, as long as it doesn't strain the RD in the big/big combination. Chain "stretch" is a separate unrelated issue. The chain seems worn based on your measurements, so it's likely the cassette is too (there's no real way to evaluate wear just by eyeballing) - since the chain and cassette are likely worn in together, I would just jeep riding them until the shifting starts to deteriorate and/or the chain starts skipping, then replace both at the same time
Litespud is offline  
Old 07-28-20, 12:29 PM
  #10  
madpogue 
Senior Member
 
Join Date: Jan 2004
Location: Madison, WI USA
Posts: 5,057
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
Quoted: 1616 Post(s)
Liked 672 Times in 514 Posts
So if the chain is worn, to the tune of 2x the traditional limit (1/16" over 12"), why would replacing it be a "mistake"?
madpogue is offline  
Old 07-28-20, 12:31 PM
  #11  
Iride01
Senior Member
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 4,373

Bikes: '20 Tarmac Disc Comp '91 Schwinn Paramount '78 Raleigh Competition GS

Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1645 Post(s)
Liked 528 Times in 405 Posts
So what functional issues are you having while riding and shifting the bike? With a 3x front your small small combo is quite a bit more chain for your DR to take up than on a typical 2x bike.

If the bike shifts well while riding, then don't be imagining things wrong.

But if you must, then please show a photo in the big big combo and maybe we can know a little better if you can take a link out to make it have the look you want. <grin>
Iride01 is offline  
Old 07-28-20, 12:38 PM
  #12  
79pmooney
A Roadie Forever
 
79pmooney's Avatar
 
Join Date: Oct 2014
Location: Portland, OR
Posts: 8,679

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 100 Post(s)
Tagged: 0 Thread(s)
Quoted: 2408 Post(s)
Likes: 0
Liked 844 Times in 571 Posts
Your small-small derailleur position is exactly what I set my triples up to. I wouldn't change anything (except get a new chain and probably cassette and maybe chainrings. (Now it is possible the new chain will flunk the large-large combo. I always insure I can 1) get into that gear and 2) it isn't a strain on the derailleur to do so. I don't like walking home.)
79pmooney is offline  
Likes For 79pmooney:
Old 07-28-20, 02:56 PM
  #13  
tommyd49
Senior Member
Thread Starter
 
Join Date: Aug 2007
Location: Cambridge, UK
Posts: 160
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Iride01 View Post
So what functional issues are you having while riding and shifting the bike? With a 3x front your small small combo is quite a bit more chain for your DR to take up than on a typical 2x bike.

If the bike shifts well while riding, then don't be imagining things wrong.

But if you must, then please show a photo in the big big combo and maybe we can know a little better if you can take a link out to make it have the look you want. <grin>
Originally Posted by Litespud View Post
If the chain is still under tension in the small/small combination, and the long lower stretch isn't rubbing against the chain wrapping around the upper jockey wheel, then you're all good - this is as slack as it's going to get, and as others have said, you're not likely to be using this chainring-sprocket combination in the wild.
The issue is that the above does happen, i.e. the lower part of the chain does rub against the RD top jockey wheel. They grind together, which in turn pushes the chain off the centre of the RD jockey wheels, so the chain basically locks up. This is something I'd like to avoid in case of shifting to the combination even by mistake.

I should point out that I plan to sell this bike to a friend for cheap. When I picked it up I thought it could be a decent runner if I could fix issues with the gears. Hence me preferring to fix the issue.

I did try to make a video showing the slack in the big-big combination. I posted it on Youtube - link here. Feel free to watch and tell me if you think it's a good look.
tommyd49 is offline  
Old 07-28-20, 03:07 PM
  #14  
Iride01
Senior Member
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 4,373

Bikes: '20 Tarmac Disc Comp '91 Schwinn Paramount '78 Raleigh Competition GS

Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1645 Post(s)
Liked 528 Times in 405 Posts
If the vid is the big big, then you probably can take a link or two out of the chain.

Chain looks old, have you measured the distance between the pins? If you put a decent metal tape or scale up to it and the pin near the 12 inch mark is over by 1/8 inch then it's well beyond life. Many replace them when they get beyond 1/16".
Iride01 is offline  
Old 07-28-20, 03:36 PM
  #15  
Litespud
Senior Member
 
Join Date: Oct 2017
Location: Chapel Hill NC
Posts: 928

Bikes: 2000 Litespeed Vortex Chorus 10, 1995 DeBernardi Cromor S/S, Nashbar 3sp commuter

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 356 Post(s)
Liked 321 Times in 181 Posts
Originally Posted by tommyd49 View Post
The issue is that the above does happen, i.e. the lower part of the chain does rub against the RD top jockey wheel. They grind together, which in turn pushes the chain off the centre of the RD jockey wheels, so the chain basically locks up. This is something I'd like to avoid in case of shifting to the combination even by mistake.

I should point out that I plan to sell this bike to a friend for cheap. When I picked it up I thought it could be a decent runner if I could fix issues with the gears. Hence me preferring to fix the issue.

I did try to make a video showing the slack in the big-big combination. I posted it on Youtube - link here. Feel free to watch and tell me if you think it's a good look.
if the chain is rubbing then you should take out 1-2 complete links to shorten it and pull the cage downward. Put it in big/big, see how far forward you can push the lower jockey wheel forward. Every 1/2” you can push it forward before it gets strained equates to ~1” of chain (1 complete link) you can remove Just ensure that you don’t remove so many links that the RD is against its forward limit when in big/big
Litespud is offline  
Old 07-28-20, 04:50 PM
  #16  
Iride01
Senior Member
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 4,373

Bikes: '20 Tarmac Disc Comp '91 Schwinn Paramount '78 Raleigh Competition GS

Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1645 Post(s)
Liked 528 Times in 405 Posts
Here is the Shimano Service instruction for that model DR....
https://si.shimano.com/pdfs/si/SI-U-005-000-00-ENG.pdf


They do the big big + 2 links. And this is without the chain running through the DR's pulley wheels. However still this isn't a guarantee. You still need to be aware of all the places for concern regarding the chain length as specs on paper can't guarantee your specific setup isn't unique in some way.
Iride01 is offline  
Old 08-02-20, 03:00 PM
  #17  
tommyd49
Senior Member
Thread Starter
 
Join Date: Aug 2007
Location: Cambridge, UK
Posts: 160
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
So everyone, thanks for all of your tips so far.

I've had more of a thorough look at the bike over the weekend. I gave the rear derailleur a thorough lube as well as taking the rear wheel out and properly pushing it as far back in the dropouts as I could.

I then took it for a test ride. In the small-small combination, the chain is still rubbing against the derailleur jockey wheel. Difference now is that it's rubbing quite a bit less, so it's not causing the chain to come off the derailleur jockey wheel. Definitely an improvement.

Having said that, I have to say the bike does ride quite nicely and everything else is in pretty good condition. For the sake of £25 or so, I'm tempted to buy a new chain and cassette just to do the job properly. Hopefully, I won't need new chainrings. If I do, I'll probably not bother as it's getting a bit more pricey.

So, when do you normally change chainrings/cranksets? Do you tend to do them whenever you change the cassette or do you tend to wait a bit longer? I personally have never changed chainrings (or even cassettes maybe) on my own bikes as I've usually replaced the chain fairly early.

P.S. Iride01 - I'm impressed you found the manual for the derailleur on the Shimano website - I'm amazed they have one for such an old component! If I don't get a new chain I may well shorten it one link, although it's not quite so bad in big/big now.

Last edited by tommyd49; 08-02-20 at 03:05 PM.
tommyd49 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.