Go Back  Bike Forums > Bike Forums > Classic & Vintage
Reload this Page >

Gauging acceptable wear on steel chainrings?

Notices
Classic & Vintage This forum is to discuss the many aspects of classic and vintage bicycles, including musclebikes, lightweights, middleweights, hi-wheelers, bone-shakers, safety bikes and much more.

Gauging acceptable wear on steel chainrings?

Old 04-19-21, 05:58 PM
  #1  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
Gauging acceptable wear on steel chainrings?

I bought a set of steel chainrings off ebay. Their 52-36T 116 bcd and I was excited to find a cottered crank "compact double set". On inspection the inner 36t chainring has more wear than the outer and a new chain "lifts" a bit more than the outer. Any ideas on how to quantify wear on steel rings? My concern would primarily be wearing out the chains and freewheels faster, but practically speaking the 36t chainring is the most unobtanium consumable in the drive train. I can get some pictures tomorrow. Thanks
bark_eater is offline  
Old 04-19-21, 06:03 PM
  #2  
bikemig 
Senior Member
 
bikemig's Avatar
 
Join Date: Apr 2012
Location: Middle Earth (aka IA)
Posts: 18,489

Bikes: A bunch of old bikes and a few new ones

Mentioned: 158 Post(s)
Tagged: 0 Thread(s)
Quoted: 5097 Post(s)
Liked 1,670 Times in 1,098 Posts
Is it possible to wear out a steel chainring? Obviously the answer is yes but those things are pretty tough.
bikemig is offline  
Old 04-19-21, 06:11 PM
  #3  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
I've seen some pretty worn rings, but I don't think I could wear this one out in my life time. I just don't want to have to feed this ting to many freewheels. That's not even a big deal as long as they keep making cheap 5 speed freewheels.

Last edited by bark_eater; 04-19-21 at 06:31 PM.
bark_eater is offline  
Old 04-19-21, 06:27 PM
  #4  
clubman
Youngman Grand
 
clubman's Avatar
 
Join Date: Jan 2010
Location: Nova Scotia
Posts: 7,358

Bikes: roadsters, club bikes, fixed and classic

Mentioned: 105 Post(s)
Tagged: 0 Thread(s)
Quoted: 1741 Post(s)
Liked 886 Times in 588 Posts
I had a pre war Hercules with a saw toothed chainring that had to go. It could cut your finger. This is the bike with a poor replacement as the original had the name Hercules in the webbing.
clubman is offline  
Likes For clubman:
Old 04-19-21, 06:33 PM
  #5  
oldlugs
Senior Member
 
Join Date: Jan 2011
Location: NJ
Posts: 225

Bikes: Too many to list

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 62 Post(s)
Liked 13 Times in 10 Posts
I always just figured a chainring was good so long as it didn't slip and no teeth were missing.
oldlugs is offline  
Old 04-20-21, 07:20 PM
  #6  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
I tried to get pictures but lost them... using drill bits as gauges I was able to get a 1/16th bit under the rivet on the 52t ring and a 5/64th bit under the rivet on the 36t ring. I'm not sure what that all really means, except try and ride the 52t ring until I need to engage the grannie gear....
bark_eater is offline  
Old 04-21-21, 05:22 AM
  #7  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
The engineers answer...
bark_eater is offline  
Old 04-21-21, 06:29 AM
  #8  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
Here are some pictures. The 52t ring is loose enough for a 1/16th drill bit to squeeze in. The 36t will allow a 5/64 drill under the rivet. Playing with the chain it looks like the amount of slop is halved when the chain is tensioned for one side as it is when the cranks turn. I don't know what that all means, except save the 36t as a granny for the hills...


bark_eater is offline  
Old 04-21-21, 08:26 AM
  #9  
Johno59
Senior Member
 
Join Date: Oct 2016
Location: Cambridge UK
Posts: 765

Bikes: 1903 24 spd Sunbeam, 1927 Humber, 3 1930 Raleighs, 2 1940s Sunbeams, 2 1940s Raleighs, Rudge, 1950s Robin Hood, 1958 Claud Butler, 2 1973 Colnago Supers, Eddie Merckx, 2 1980 Holdsworth, EG Bates funny TT bike, another 6 or so 1990s bikes

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 307 Post(s)
Liked 252 Times in 145 Posts
Only the 3 o'clock position on the chain ring reveals meaningful data. Did Elvis write a song along those lines?
Go to the 3 o'clock position on the chain ring. As the furthermost point from the 9 o'clock position on the rear sprocket you can gauge the amount of wear on your entire drive. Pull the chain away from the teeth at the 3 o'clock position on the chain ring . If you can see half of a tooth, change the chain (cheapest option).Repeat procedure with new said chain. If the half tooth still appears your chain ring is toast. Replace and happy days.
If it still jumps - change the rear sprocket as well.
You now have a completely new drive.
Oil every day and it will stay that way, neglect the oil and you will be back sooner or later.
Johno59 is offline  
Old 04-21-21, 08:30 AM
  #10  
miamijim
Senior Member
 
miamijim's Avatar
 
Join Date: Aug 2003
Location: Tampa, Florida
Posts: 14,028
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 381 Post(s)
Likes: 0
Liked 40 Times in 35 Posts
If mounted on a bike pull the chain tight at 3:00. If you can see light at the tip of a tooth the rings are toast. Or 12:00 as in your pics..

I've never compared new large n small rings side by side but I'd guess the chain will pull further away on the small ring as there're fewer teeth engaged. That small ring has a bizzillion miles to go as both tooth 'bevel's' and machine marks are clearly visible. Pedal away....

Teeth on that particular ring are beveled in two directions, from the inside in and from the front/back towards the tip.
miamijim is offline  
Old 04-21-21, 10:09 AM
  #11  
Reynolds 
Passista
 
Reynolds's Avatar
 
Join Date: Jul 2005
Posts: 7,219

Bikes: 1998 Pinarello Asolo, 1992 KHS Montaña pro, 1980 Raleigh DL-1, IGH Hybrid, IGH Utility

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 722 Post(s)
Liked 382 Times in 221 Posts
Those rings look OK to me. Probably still good for many years of use.
Reynolds is offline  
Old 04-21-21, 10:32 AM
  #12  
ClydeClydeson
Senior Member
 
Join Date: Mar 2019
Posts: 673
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 220 Post(s)
Liked 287 Times in 200 Posts
Rings can wear to a point where the shape of the teeth changes visibly. Those rings do not look like that. You expect to see a difference between the front and back edge of each tooth, and a bit of an extended flat section between. Neither are visible there.

My first question: is that a new chain? Because lifting off the chainrings is one way to determine if there is wear in the chain, and the same chainring can be used over the life of many chains, if the chains are changed regularly.
ClydeClydeson is offline  
Old 04-21-21, 11:46 AM
  #13  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
It's a new chain. The industrial sprocket web link put 10% of tooth width worn away as the replacement point. MKII eyeball and a Harbor Freight caliper puts the small ring at 10% compared to a NOS Nervar ring. The Nervar ring has chromed over burs on the teeth so that's probably a pessimistic comparison. I'm assuming that there's an tolerance spec for 1/2" chain.


Here's an illustration from the link. If a roller is 7.75mm in diameter adding 10% gets you 8.525mm. 8.5 mm drill bits are available, I wonder if one could be used as a No-Go tooth gauges?

I get the idea of the 3 o'clock test, and having the chain tensioned back to the sprockets, will reduce the amount of slop, so there would be less lift than with how I have the unmounted chainring and drill bit. I tried tensioning the chain in the proper direction and it looked like the gap was significantly reduced, but I only have 2 hands...
bark_eater is offline  
Old 04-21-21, 12:49 PM
  #14  
miamijim
Senior Member
 
miamijim's Avatar
 
Join Date: Aug 2003
Location: Tampa, Florida
Posts: 14,028
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 381 Post(s)
Likes: 0
Liked 40 Times in 35 Posts
Originally Posted by bark_eater View Post

I get the idea of the 3 o'clock test, and having the chain tensioned back to the sprockets, will reduce the amount of slop, so there would be less lift than with how I have the unmounted chainring and drill bit. I tried tensioning the chain in the proper direction and it looked like the gap was significantly reduced, but I only have 2 hands...
Dont tensioin it. Just pull at 3 o'clock. Its a bike sprocket not a rocket ship. Dont over analyze.
miamijim is offline  
Old 04-21-21, 07:54 PM
  #15  
ThermionicScott 
7-speed cultist
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 20,120

Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers)

Mentioned: 88 Post(s)
Tagged: 0 Thread(s)
Quoted: 2798 Post(s)
Liked 755 Times in 531 Posts
The only meaningful test is whether the chain skips under load. End of story.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498
ThermionicScott is offline  
Old 04-21-21, 08:01 PM
  #16  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
There was no mention of pixy dust. I looked...

https://www.renold.com/company/lates...worn-sprockets
bark_eater is offline  
Old 04-21-21, 08:14 PM
  #17  
cudak888 
www.theheadbadge.com
 
cudak888's Avatar
 
Join Date: Sep 2005
Location: Southern Florida
Posts: 26,464

Bikes: https://www.theheadbadge.com

Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 1499 Post(s)
Liked 1,734 Times in 1,002 Posts
Originally Posted by ThermionicScott View Post
The only meaningful test is whether the chain skips under load. End of story.
Not far from the truth. Curious what quality of steel chainring/cranks the OP has though.

-Kurt
__________________







cudak888 is offline  
Old 04-21-21, 08:21 PM
  #18  
zandoval 
Senior Member
 
zandoval's Avatar
 
Join Date: May 2010
Location: Bastrop Texas
Posts: 2,063

Bikes: Univega, PR-10, Ted Williams,UO-8, Puch, PHLE, UO-18 Mixte

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 98 Post(s)
Liked 86 Times in 68 Posts
When they are worn enough that I can see changes, I replace them. They seem to last longer if riding on clean roads. Dirty roads = Dirty chains = Worn out cranks... Ha
__________________
No matter where your at... There you are... Δf:=f(1/2)-f(-1/2)
zandoval is offline  
Old 04-21-21, 08:55 PM
  #19  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
Originally Posted by cudak888 View Post
Not far from the truth. Curious what quality of steel chainring/cranks the OP has though.

-Kurt
Their Cylos (sp?) and I got to say the rule of thumb push back is a little weird.....

Last edited by bark_eater; 04-23-21 at 04:14 AM.
bark_eater is offline  
Old 04-22-21, 07:08 AM
  #20  
PugRider
Senior Member
 
Join Date: Feb 2013
Location: Worcester, Massachusetts
Posts: 239

Bikes: Fuji Sportif 1.7C, Centurion Ironman, Shogun Metro AT, Jamis Durango SX, Miyata Alumicross, Fuji Special Road Racer, Mongoose ATB, Fuji SST 1.0 Team, Gitane (?), Specalized Rockhopper SS, Univega Gran Turismo

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 59 Post(s)
Liked 77 Times in 38 Posts
I thought I first saw it at Sheldon's, but I'm having trouble finding it. But one tip I recently discovered is to use a loose roller from a chain, pick it up with a set of needle-nose pliers, and fit it into the chainring. If it seems nicely nestled in there, then the chainring is good. If the valley is wide and the chainring teeth don't really come up the sides of the roller, then it's worn out. Hard to describe, but it's really obvious if you do it with a chainring you know is good, and then test it out on one you think is bad.
PugRider is offline  
Old 04-23-21, 02:35 PM
  #21  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
I gave that a try, and a roller in a new chainring has zero play. Referring back to the diagram, it looks like if there is any play with the roller at the bottom of the trough, the wear point may have gone beyond 10%, but I have no idea how accurate that illustration realy is. I played with a drill index a bit more, and where there is visible wear further up the tooth an 11/64 bit would lock in to the groove, above the bottom. The next thing to play with would be the 2 5/32" drill bits approximately 1/2 a roller diameter to space a caliper off the bottom of the valley. That would be ball park, but even with spacers exactly 1/2 the rollers diameter the measurement will be off as it will be a straight line tangent bellow the PCD radius. The greater the diameter of the chainring the less this is a factor....

Last edited by bark_eater; 04-23-21 at 04:35 PM.
bark_eater is offline  
Old 04-23-21, 08:45 PM
  #22  
Reynolds 
Passista
 
Reynolds's Avatar
 
Join Date: Jul 2005
Posts: 7,219

Bikes: 1998 Pinarello Asolo, 1992 KHS Montaña pro, 1980 Raleigh DL-1, IGH Hybrid, IGH Utility

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 722 Post(s)
Liked 382 Times in 221 Posts
There's a Rohloff sprocket wear gauge, I guess you can use it on a chainring too.




I made one but it wasn't of much use - when it said "worn out sprocket, replace" you could as well see that by eye...

Last edited by Reynolds; 04-23-21 at 08:49 PM.
Reynolds is offline  
Old 04-24-21, 05:16 AM
  #23  
bark_eater 
Senior Member
Thread Starter
 
Join Date: Sep 2017
Location: Eastern Shore, MD
Posts: 1,352

Bikes: Road ready: 1993 Koga Miyata City Liner Touring Hybrid, 1989 Centurion Sport DLX, "I Blame GP" Bridgestone CB-1. Projects: Yea, I got a problem....

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 452 Post(s)
Liked 194 Times in 144 Posts
I've been meaning to get one of those. The instructions say that they only work to 21T. Roller chain and sprocket technology must be getting close to 200 years in use, so I'm sure this has been covered before. I just need to find the right critical application that is relevant to 1/2" chain drives.
bark_eater is offline  
Old 04-24-21, 11:13 AM
  #24  
Sluggo
Senior Member
 
Sluggo's Avatar
 
Join Date: Oct 2005
Location: Left bank, Knoxville TN
Posts: 584
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Liked 84 Times in 41 Posts
Can you turn the chainring over and use the unworn side?
Sluggo is offline  
Likes For Sluggo:
Old 04-24-21, 12:13 PM
  #25  
Hobbiano 
Senior Member
 
Join Date: Sep 2014
Location: Baton Rouge La
Posts: 828
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 250 Post(s)
Liked 139 Times in 100 Posts
Check out the pictures of worn out vs new chainrings here: Chainring wear visualized
Yours look closer to the new end of the spectrum to me. I don't think you need to actually measure it to come to that conclusion.
Hobbiano 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 © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.