What causes this?
04-18-23, 03:35 PM
#1
Junior Member
Thread Starter
What causes this?
This is from a donated bike so I don't know the history. 1 x 7 schwinn cruiser type bike with the symptom being a "juddery" feeling, present on all rear cogs but progressively worse as you approach the smallest cog. I took the chain guard off to find what is pictured. Chain shows little wear using the chain gauge. I took the chain off and it doesn't have any stiff links. I have checked the RD for alignment and it is OK, and the jockey wheels are running smoothly. I don't have another chain to try; what I think I am feeling is the chain vs. front gear as it leaves the gear. Is this chain shot even though it doesn't show it on the gauge. Thanks!
04-18-23, 03:55 PM
#2
Senior Member
Join Date: Jan 2014
Posts: 634
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 230 Post(s)
Likes: 0
Liked 18 Times
in
11 Posts
What you've taken a photo of there is extreme chain wear. You'll also need to replace the freewheel, and honestly i'd take a good hard look at the chainring too.
Likes For Cute Boy Horse:
04-18-23, 04:39 PM
#3
I am potato.
Join Date: Jun 2015
Location: Pacific Northwest
Posts: 3,116
Bikes: Only precision built, custom high performance elitist machines of the highest caliber. 🍆
Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 1790 Post(s)
Liked 1,631 Times
in
934 Posts
+1 on the extreme chain wear. But in the odd chance it is not...It could be a 1/8 (4/32) chainring being too wide for a 3/32 chain.
In either case, a new proper chain is in order.
Cheers.
In either case, a new proper chain is in order.
Cheers.
__________________
I shouldn't have to "make myself more visible;" Drivers should just stop running people over.
Car dependency is a tax.
I shouldn't have to "make myself more visible;" Drivers should just stop running people over.
Car dependency is a tax.
Likes For base2:
04-18-23, 04:53 PM
#4
Senior Member
Join Date: Jul 2015
Location: NW Oregon
Posts: 2,975
Bikes: !982 Trek 930R Custom, Diamondback ascent with SERIOUS updates, Fuji Team Pro CF and a '09 Comencal Meta 5.5
Mentioned: 15 Post(s)
Tagged: 1 Thread(s)
Quoted: 1299 Post(s)
Liked 739 Times
in
534 Posts
an extremely Low Quality Chain, Lousy chain lube(if any) and obvious Neglect.... with a chance of a bent tooth or chainring... but all that offset pictured leads me to think it's that chain... !
set a new chain around the chainring,,, pull it tight.... then try to pull it outwards from the mid point opposite the end... see if it lifts more than 1/2 a tooth height... if so, then the ring is shot.
set a new chain around the chainring,,, pull it tight.... then try to pull it outwards from the mid point opposite the end... see if it lifts more than 1/2 a tooth height... if so, then the ring is shot.
Last edited by maddog34; 04-18-23 at 05:04 PM.
04-18-23, 04:57 PM
#5
Senior Member
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 4,398
Bikes: '80 Masi Gran Criterium, '12 Trek Madone, early '60s Frejus track
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 514 Post(s)
Liked 451 Times
in
339 Posts
[QUOTE=base2;22864082But in the odd chance it is not...It could be a 1/8 (4/32) chainring being too wide for a 3/32 chain.
In either case, a new proper chain is in order.
Cheers.
[/QUOTE]
Just worn. Observe how the links mesh with the cog at the bottom. If the chain were too narrow, it couldn't have been used long enough to cause elengation, unless, maybe, diabolically, it was worn out on a different bike and then transferred to this one.
In either case, a new proper chain is in order.
Cheers.
[/QUOTE]Just worn. Observe how the links mesh with the cog at the bottom. If the chain were too narrow, it couldn't have been used long enough to cause elengation, unless, maybe, diabolically, it was worn out on a different bike and then transferred to this one.
Likes For oldbobcat:
04-19-23, 07:56 AM
#6
I'm good to go!
Join Date: Jul 2017
Location: Mississippi
Posts: 15,012
Bikes: Tarmac Disc Comp Di2 - 2020
Mentioned: 51 Post(s)
Tagged: 0 Thread(s)
Quoted: 6203 Post(s)
Liked 4,818 Times
in
3,323 Posts
Chain ring is worn if you are sure the chain measures within spec. Perhaps the previous chain was used well beyond time to replace and that wore out the ring and probably some of the rear cogs too.
04-19-23, 09:37 AM
#7
Senior Member
Join Date: Mar 2012
Posts: 982
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 506 Post(s)
Likes: 0
Liked 639 Times
in
357 Posts
This is from a donated bike so I don't know the history. 1 x 7 schwinn cruiser type bike with the symptom being a "juddery" feeling, present on all rear cogs but progressively worse as you approach the smallest cog. I took the chain guard off to find what is pictured. Chain shows little wear using the chain gauge. I took the chain off and it doesn't have any stiff links. I have checked the RD for alignment and it is OK, and the jockey wheels are running smoothly. I don't have another chain to try; what I think I am feeling is the chain vs. front gear as it leaves the gear. Is this chain shot even though it doesn't show it on the gauge. Thanks!
Likes For KerryIrons:
04-19-23, 12:26 PM
#8
Junior Member
Thread Starter
Clearly a case of a severely worn chain or chain ring. You say the chain is OK by your chain checker. I suggest getting out a ruler and measuring the chain. It should be less than 1/8" elongated in 12" original length (1% elongation). The current spec is actually 0.5% elongation (1/16" in 12") but with these low quality setups, and 7 speed, 1/8" is OK. You have way more issue than that.
04-19-23, 03:34 PM
#9
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,100
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4212 Post(s)
Liked 3,883 Times
in
2,318 Posts
Likes For Andrew R Stewart:
04-20-23, 08:41 PM
#10
Droid on a mission
Join Date: May 2018
Location: Palm Coast, FL
Posts: 1,005
Bikes: Diamondback Wildwood Classic
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 317 Post(s)
Liked 280 Times
in
195 Posts
Look this video about the 2:50 mark and will see the tool bouncing off the closer rivet.
__________________
JoeTBM (The Bike Man) - I'm a black & white type of guy, the only gray in my life is the hair on my head
www.TheBikeMenOfFlaglerCounty.com
JoeTBM (The Bike Man) - I'm a black & white type of guy, the only gray in my life is the hair on my head
04-21-23, 06:04 AM
#11
Sock Puppet
Join Date: Oct 2022
Location: Planet Earth
Posts: 1,701
Bikes: 2014 Cannondale Synapse Carbon, 2017 Jamis Renegade Exploit and too many others to mention.
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 1031 Post(s)
Liked 863 Times
in
573 Posts
Bicycle: Measuring Chain Wear using a 12-Inch Ruler
The ruler does not lie!
04-21-23, 07:23 AM
#12
Junior Member
Thread Starter
Extremely worn chains may yield a false "good" because the checker is hitting the roller closer to the "hook" end. I always have a steel rule on hand in addition to the chain checker.
Look this video about the 2:50 mark and will see the tool bouncing off the closer rivet.
https://www.youtube.com/watch?v=gXd-3UnqoaM
Look this video about the 2:50 mark and will see the tool bouncing off the closer rivet.
https://www.youtube.com/watch?v=gXd-3UnqoaM
04-21-23, 07:34 AM
#13
Senior Member
Join Date: Oct 2022
Posts: 1,378
Bikes: a couple
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 563 Post(s)
Liked 863 Times
in
456 Posts
That's an old schwinn, love that Ashtabula crank.
My bad, not a single speed! the front sprocket will be fine, the rear not so much.
My bad, not a single speed! the front sprocket will be fine, the rear not so much.
Last edited by Schweinhund; 04-21-23 at 07:42 AM.
04-21-23, 09:48 AM
#14
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,369
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 152 Post(s)
Tagged: 1 Thread(s)
Quoted: 6222 Post(s)
Liked 4,222 Times
in
2,368 Posts
Extremely worn chains may yield a false "good" because the checker is hitting the roller closer to the "hook" end. I always have a steel rule on hand in addition to the chain checker.
Look this video about the 2:50 mark and will see the tool bouncing off the closer rivet.
Look this video about the 2:50 mark and will see the tool bouncing off the closer rivet.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
04-21-23, 11:57 AM
#15
Junior Member
Thread Starter
That checker isn’t showing a “false good” at all. The “bouncing” of the hook end is because the mechanic is moving the checker to illustrate that the chain is worn beyond 0.75%…well beyond at that. The chain checker in that video shows that the chain is obviously worn. The only way that measurement would show a “false good” is if the person doing the measurement didn’t know how the tool worked. No steel rule is needed to further check the results.
Likes For louky:
