Worn Chainring?

Workshop tales, trials and disasters.
Maintenance tips, techniques and myths.
Technical discussion, description and outright lies

Worn Chainring?

Postby heuston » Tue Feb 25, 2014 11:31 pm

I think the my large chainring (50T) might be on its way out but given all the tooth profiling that goes on I'd really appreciate a second opinion.ImageImage
heuston
 
Posts: 26
Joined: Thu Feb 21, 2013 6:53 am

by BNA » Wed Feb 26, 2014 12:47 am

BNA
 

Re: Worn Chainring?

Postby Duck! » Wed Feb 26, 2014 12:47 am

I reckon that's still got some life in it. What sort of distance do you reckon it's done?
I had a thought, but it got run over as it crossed my mind.
Duck!
Expert
 
Posts: 1890
Joined: Tue May 21, 2013 8:21 pm
Location: On The Tools

Re: Worn Chainring?

Postby MN GLXR » Wed Feb 26, 2014 5:37 am

With a chain on the ring, how far can you lift the links off the ring? Is it snug or loose?
MN GLXR
 
Posts: 30
Joined: Wed Oct 24, 2012 1:07 pm

Re: Worn Chainring?

Postby Marx » Wed Feb 26, 2014 6:25 am

Can you lift a chain link at 3 o'clock on the chainwheel & get more than half a tooth's height of daylight underneath?

If you can, then you still have plenty of kms left in it... :wink:
-----------------------
A bike and a place to ride.
User avatar
Marx
 
Posts: 212
Joined: Mon Jun 15, 2009 12:36 pm
Location: Kensington Melbourne Australia

Re: Worn Chainring?

Postby KGB » Wed Feb 26, 2014 7:29 am

Lifting the chain is more an indication of chain wear ("stretch") than ring wear.

Still some life there IMO
Image
User avatar
KGB
 
Posts: 745
Joined: Tue Jul 12, 2011 3:49 pm

Re: Worn Chainring?

Postby heuston » Wed Feb 26, 2014 8:08 am

Only about 7,000kms on the chainring - 95% of which would be on the big ring. About half way through my third chain in that time. I realise this is not a lot of 'mileage' for chainrings but it cops a bit from the commute, rain and overall drivetrain neglect.
It hasn't been slipping but the fin like shapes which are emerging concerned me.
heuston
 
Posts: 26
Joined: Thu Feb 21, 2013 6:53 am

Re: Worn Chainring?

Postby jules21 » Wed Feb 26, 2014 9:39 am

my experience is that the chainring needs replacing when the chain starts slipping. this usually happens when i fit a new chain - which won't engage with a sufficiently worn 'ring.

running a chainring to 'failure' probably wears chains faster, but chains are cheaper than 'rings so i think it makes sense.

i always keep a set of spare 'rings so that i don't have to park the bike while waiting for replacements to arrive.
Image
User avatar
jules21
 
Posts: 8733
Joined: Thu Apr 02, 2009 10:14 pm
Location: deep in the pain cave

Re: Worn Chainring?

Postby RonK » Wed Feb 26, 2014 12:03 pm

Looks ok to me...
Image
Cycle touring blog and tour journals: whispering wheels...
User avatar
RonK
 
Posts: 5369
Joined: Mon Aug 24, 2009 2:08 pm
Location: Brisbane, Queensland

Worn Chainring?

Postby heuston » Wed Feb 26, 2014 4:21 pm

Thanks RonK - looks like the teeth are already a bit fin like to start with. Think I'll just keep them on until they start slipping 'cos damned if in can tell what a worn one looks like.
heuston
 
Posts: 26
Joined: Thu Feb 21, 2013 6:53 am

Re: Worn Chainring?

Postby RonK » Wed Feb 26, 2014 5:21 pm

Yeah, unless you are very familiar with them it's difficult to gauge the wear visually.

I don't think you need a replacement, but they aren't too expensive to have a spare handy which can be used as a reference.

Maybe order one with your next chain.
Cycle touring blog and tour journals: whispering wheels...
User avatar
RonK
 
Posts: 5369
Joined: Mon Aug 24, 2009 2:08 pm
Location: Brisbane, Queensland

Re: Worn Chainring?

Postby Marx » Wed Feb 26, 2014 6:33 pm

off topic, but I personally don't understand how new chains on worn chainrings/cogs helps things?
I just ride the whole groupset into the ground & replace everything in one go, the indicator being a jumping chain on my most popular cassette cog.
-----------------------
A bike and a place to ride.
User avatar
Marx
 
Posts: 212
Joined: Mon Jun 15, 2009 12:36 pm
Location: Kensington Melbourne Australia

Re: Worn Chainring?

Postby Nobody » Wed Feb 26, 2014 7:10 pm

Marx wrote:off topic, but I personally don't understand how new chains on worn chainrings/cogs helps things?
It saves money by allowing you to get the maximum life you can from each component. I usually change the chain when the length measurement indicates it should be, then see how everything else sounds or feels. Last time I knew the big chainring was finished because after I changed the chain and cassette, I could hear the chain make an odd rattling/chattering sound. It was so loud peds could hear me coming. Once I changed the chainring, the chattering stopped.
Nobody
 
Posts: 6649
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Worn Chainring?

Postby KGB » Wed Feb 26, 2014 7:10 pm

New chains on very worn cogs won't work, it will skip. Even if it doesn't work, the worn cogs will accelerate the wear on the new chain.

What most people advocate is rotating between 3 chains every 1000km or so. Since the chain is what wears out the cogs, a worn and "stretched" chain will increase this rate of wear. By keeping new-ish, good condition chains on the bike you minimise the rate of wear on the cogs and that's the whole point.
New cassette on my bike = $200. New chain, about $40 at most.

Riding the whole lot into the ground is fine if that works for you. On a high end 10 or 11 speed road bike most people won't tolerate the degradation in shifting you get as you begin to run it into the ground. It will still "work" but not as well as it should.
On my 7 speed mtb, the shifting is more robust, largely due to the fact that there is so much more travel between cogs. This decreased sensitivity to wear and adjustment, plus the fact I don't race my mtb means I'm pretty much following the run it into the ground method for that bike.
Image
User avatar
KGB
 
Posts: 745
Joined: Tue Jul 12, 2011 3:49 pm

Re: Worn Chainring?

Postby Duck! » Thu Feb 27, 2014 1:07 pm

Chainrings are longer-lived due to the large contact area. Unless you persist with a badly-worn chain, which will sit on the tips of the teeth rather than mesh properly, then it will rapidly wear the teeth off. If your chains are replaced before they're allowed to go too far, rings will last a very long time.
I had a thought, but it got run over as it crossed my mind.
Duck!
Expert
 
Posts: 1890
Joined: Tue May 21, 2013 8:21 pm
Location: On The Tools

Re: Worn Chainring?

Postby dontazame » Tue Mar 04, 2014 7:24 am

Does anyone else rotate their small chain ring? I find it wears way quicker than the large, and there is a definite wear pattern.
dontazame
 
Posts: 68
Joined: Fri Nov 25, 2011 8:09 pm

Re: Worn Chainring?

Postby Hugh Stone » Tue Mar 04, 2014 7:33 am

I rotate it every time I ride :-)
Hugh Stone
 
Posts: 24
Joined: Mon Mar 03, 2014 11:58 am

Re: Worn Chainring?

Postby scotto » Tue Apr 01, 2014 10:33 pm

Rotate the chainring ??!!! It's April 1 today At least !!
User avatar
scotto
 
Posts: 2351
Joined: Tue Dec 01, 2009 8:38 am
Location: Baulkham Hills

Re: Worn Chainring?

Postby ColinOldnCranky » Tue Apr 01, 2014 11:22 pm

KGB wrote:Lifting the chain is more an indication of chain wear ("stretch") than ring wear.

Still some life there IMO

I haven't thought it through but I would have thought that that was more a case of how much stretch there is in the chain.
Unchain yourself - Ride a unicycle .Image
User avatar
ColinOldnCranky
 
Posts: 4736
Joined: Fri Feb 27, 2009 3:58 pm

Re: Worn Chainring?

Postby kb » Wed Apr 02, 2014 2:34 pm

Not if you use a new chain though.
Image
User avatar
kb
 
Posts: 911
Joined: Sun Nov 13, 2011 2:22 pm


Return to The Shed

Who is online

Users browsing this forum: Blakeylonger, cage, Dragster1, Google [Bot], human909



Popular Bike Shops
Torpedo 7 Torpedo7 AU
Ground Effect Ground Effect NZ
Chain Reaction Cycles CRC UK
Wiggle Wiggle UK
Ebay Ebay AU

“Bicycles BNA Twitter
“Bicycles BNA Facebook
“Google+ BNA Google+
“Bicycles BNA Newsletter

> FREE BNA Stickers
> BNA Cycling Kit