A Cycling & bikes forum. CycleBanter.com

Go Back   Home » CycleBanter.com forum » rec.bicycles » Techniques
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Correct way to measure chain wear?



 
 
Thread Tools Display Modes
  #1  
Old July 10th 03, 11:53 PM
Ken Nishimura
external usenet poster
 
Posts: n/a
Default Correct way to measure chain wear?

Started to wonder about the correct way to measure chain wear. Option
1 is to buy a chain checker (e.g. Park CC-2). Option 2 is to measure...

Conventional wisdom is to measure 12 links and if it is greater than
12.125", then the chain is worn and should be replaced. Fine.

However, the chain really has three main places of wear:

1) Inner plate to pin
2) Inner surface of rollers to pin
3) Outer surface of rollers

Now, measuring 12 links only takes into account wear mechanism (1).
It could be that this is the major wear mechanism, as the loads are
most concentrated being the smallest interface area. However, what
the chainrings and cogs care about is the pitch of the chain as measured
from outer surface of one roller to the next. So, if the rollers become
worn so they are "thinner" than they originally were, the pitch of
the chain could increase, even if we the inner plates do not wear.

Question:

1) Are wear mechanisms (2) and (3) negligible?
2) Would it make more sense to measure 12 links from roller surface to
roller surface (using calipers or something of the sort) instead of
pin to pin?
3) If (2) is true, then does the Park CC-2 do the correct thing as it sits
on top of the chain?


Ads
  #2  
Old July 11th 03, 12:04 AM
Jim Price
external usenet poster
 
Posts: n/a
Default Correct way to measure chain wear?

Ken Nishimura wrote:

Started to wonder about the correct way to measure chain wear. Option
1 is to buy a chain checker (e.g. Park CC-2). Option 2 is to measure...

Conventional wisdom is to measure 12 links and if it is greater than
12.125", then the chain is worn and should be replaced. Fine.

However, the chain really has three main places of wear:

1) Inner plate to pin
2) Inner surface of rollers to pin
3) Outer surface of rollers

Now, measuring 12 links only takes into account wear mechanism (1).
It could be that this is the major wear mechanism, as the loads are
most concentrated being the smallest interface area. However, what
the chainrings and cogs care about is the pitch of the chain as measured
from outer surface of one roller to the next. So, if the rollers become
worn so they are "thinner" than they originally were, the pitch of
the chain could increase, even if we the inner plates do not wear.

Question:

1) Are wear mechanisms (2) and (3) negligible?
2) Would it make more sense to measure 12 links from roller surface to
roller surface (using calipers or something of the sort) instead of
pin to pin?
3) If (2) is true, then does the Park CC-2 do the correct thing as it sits
on top of the chain?


Measuring from any two consistent positions on the ouside of the chain
will give almost identical results - you have to make the measurement
with the chain under some tension. The most wear happens in the order
1-2-3. External measurement of the chain does take into account
mechanism 2, as you describe it, if the chain is under tension.

--
Jim Price

http://www.jimprice.dsl.pipex.com

Conscientious objection is hard work in an economic war.

Aye!.

  #3  
Old July 11th 03, 01:45 PM
Peter Cole
external usenet poster
 
Posts: n/a
Default Correct way to measure chain wear?


"Ken Nishimura" wrote in message
...
Started to wonder about the correct way to measure chain wear. Option
1 is to buy a chain checker (e.g. Park CC-2). Option 2 is to measure...

Conventional wisdom is to measure 12 links and if it is greater than
12.125", then the chain is worn and should be replaced. Fine.

However, the chain really has three main places of wear:

1) Inner plate to pin
2) Inner surface of rollers to pin
3) Outer surface of rollers

Now, measuring 12 links only takes into account wear mechanism (1).
It could be that this is the major wear mechanism, as the loads are
most concentrated being the smallest interface area. However, what
the chainrings and cogs care about is the pitch of the chain as measured
from outer surface of one roller to the next. So, if the rollers become
worn so they are "thinner" than they originally were, the pitch of
the chain could increase, even if we the inner plates do not wear.

Question:

1) Are wear mechanisms (2) and (3) negligible?
2) Would it make more sense to measure 12 links from roller surface to
roller surface (using calipers or something of the sort) instead of
pin to pin?
3) If (2) is true, then does the Park CC-2 do the correct thing as it sits
on top of the chain?


You're over-analyzing this. The only thing that's important in chain wear is
change of pitch. Wear of the pins and the diameter of the inner plates that
bears on the pins are the only things that affect pitch, since the wear is
cumulative with respect to change in chain length. Roller wear isn't
cumulative.


  #4  
Old July 12th 03, 12:41 AM
TBGibb
external usenet poster
 
Posts: n/a
Default Correct way to measure chain wear?

In article , Ken Nishimura
writes:

Conventional wisdom is to measure 12 links and if it is greater than
12.125", then the chain is worn and should be replaced. Fine.


If it gets that far you will likely have to replace your cassette or freewheel
too.

Tom Gibb
 




Thread Tools
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cake Chain Crunch Cliff Holloway Mountain Biking 22 April 15th 04 07:05 AM
What's the best chain cleaner & degreaser? [email protected] Mountain Biking 0 April 8th 04 06:05 PM
chain skipping phil Mountain Biking 7 February 26th 04 04:41 AM
Chain and pin Giovanni Mountain Biking 3 December 4th 03 11:53 PM
Chain Cleaning "toy" Scott C Techniques 8 July 13th 03 01:23 PM


All times are GMT +1. The time now is 03:42 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 CycleBanter.com.
The comments are property of their posters.