Chain Ring wear

[Giff]

I checked my chain with a Silverline gauge and it says it was worn past the1.0 mark.

I have got a new chain but it seems to slip and jump low end gears all the time.

Is my chain ring worn ( pic enc) and should I have replaced them together ?

Thanks for any advice.G.

 

[Gary]

You can clearly see the chainring teeth are worn. (the profile of each tooth is symetrical when new). Although not worn to the point of being completely useless with your overly worn chain, efficiency and chain retention will be worse because of the wear.

Your new chain is slipping in the smaller cassette sprockets because they are worn (worn to a similar extent to your old chain).

either put your old chain back on and run that into the ground replacing chain, cassette and chainring at that point.

or

replace your cassette to use your new chain.
your new chain probably runs fine on the worn chainring just now. But the wear from the ring will increase wear on your new chain AND reduce chain retention. Were you to continue using the worn ring with new chain/cassette the chainring will eventually become worn to the point of even more hooked teeth and you'd eventually have issues with chain suck... something you really don't want to encounter on a motor driven drivetrain as the ring will continue turning a jammed chain into your chainstay/motor/frame

 

[Giff]

Thanks for the advice Gary. Putting there old chain back on has stopped the slipping.

So would the advice be:

1. Replace the chain sooner before it is past both wear levels on the gauge.

2. Only replace the chain / chain ring and cassette together.

 

[GrahamPaul]

So would the advice be:

1. Replace the chain sooner before it is past both wear levels on the gauge.

2. Only replace the chain / chain ring and cassette together.

AIUI, the answer to your question is "Yes".

There are two approaches. Some on here have two (often three) chains which they regularly rotate, from new, in the belief that this reduces wear to the chain ring and cassette. The disadvantage is the cost of one or two extra chains which may (or may not) increase the lifespan of the complete drivetrain.

Others on here just ride their bikes until the chain skips and jumps so much that it's horrible to ride and then replace the whole drive train.

A halfway house is to replace the chain as soon as it shows 0.5% extension.

The choice is yours. Although, currently you have adopted the second option.

 

[Giff]

Yes I have so far but currently looking at the replacement option !

Can anyone help me decide how to tell tell if I have a SRAM "boost"chainring ? The buying option specify a 3mm offset. Is this the standard replacement....

 

[Jamy]

Yes I have so far but currently looking at the replacement option !

Can anyone help me decide how to tell tell if I have a SRAM "boost"chainring ? The buying option specify a 3mm offset. Is this the standard replacement....

what bike do you have and what year

 

[Giff]

Cube Hybrid Reaction Pro. 2020 model. Bosch gen 4 motor.

 

[Jamy]

I have the SL version of that bike. I replaced the chain after 1000 miles when it was .5% worn. By the time the second chain is worn down to .5% I will be ready for a new front chain ring and new rear cassette. Think I'll just get my LBS to do the work as I don't have all the tools to do the job myself
your chain ring is listed as ACID E-Crank, 38T, 175mm

 

[Giff]

Thanks Jammy. Yes I've done over 3000km now and I think they need replacing. I have the 38T, 175mm info but it doesn't mention the 3mm Boost offset.
I was assuming that was standard ?

 

[Giff]

.....but on the order options I have a 3mm offset Boost or 6mm offset. Does anyone know which is correct.
I can't see anything written on the existing chainring.

 

[Jamy]

I don't even know how to find a replacement chainring. I can't find a ACID E-Crank, 38T, 175mm .
Or Acid made by Cube? my bike as the same crank as yours

 

[Giff]

I had a problem with finding a headset bearing ( last year) . I asked Cube who gave me their internal part number which was hopeless.They said to contact my lbs.

My lbs (where I bought the bike has been closed since lockdown so not much help there.

 

[boBE]

I used to ride a rail trail that was surfaced with "screenings", sort of sandpaper without the paper. I replaced the chain every year, the chainwheel and cassette every other year. Now I ride a trail that is hardpack with fine sand, here we go again.
Chainwheel ~ $60, cassette ~ $80.

 

[Jamy]

I find it frustrating the bike manufacturers don't use proper part codes. On my bike (CUBE SL625)
it states:
Chain- sram SX Eagle yet there's no such thing as a SX chain from SRAM
Brakes - Magura MT Thirty yet there's no such model on Magura website, infact it 4 emails to Magura before they worked out what they are
Crankset - ACID E-Crank, 38T, 175mm yet I can not find anything on any website relating to this crank

 

[Giff]

As I have the same problem I’m going to bite the bullet and order a 3mm boost offset chainring.
I can check it against the old one when I take that off. If it’s different I will have to do a return and re-order.
Before I get my next bike I am going to give the dealer a list of spares and ask for part nos / codes before I part with any cash for the new bike! ?

 

[Jamy]

As I have the same problem I’m going to bite the bullet and order a 3mm boost offset chainring.
I can check it against the old one when I take that off. If it’s different I will have to do a return and re-order.
Before I get my next bike I am going to give the dealer a list of spares and ask for part nos / codes before I part with any cash for the new bike! ?

it looks like this is the one you want SRAM 38t Bosch Direct Mount 11/12-Speed X-Sync2 Eagle Chainring, Black

 

[Giff]

Thanks for the link. That does look correct and it's steel and a lot I have seen online are aluminium. I'm not sure they will ship to the UK so I will see if that part is available here.
Thanks again

 

[Beekeeper]

What do people do with their old chains? Bin them? Recycle them? Wear them? Where do all those chains go?

 

[Jamy]

What do people do with their old chains? Bin them? Recycle them? Wear them? Where do all those chains go?

mines sat in my tool box "just in Case"

 

[Giff]

Home made chain wrench?

 

[steve_sordy]

My chain goes into the recycle bin of course!

 

[Varaxis]

I have a scrap metal pile that I let accumulate, before taking it to recyclers who pay like pennies per pound of mixed metal. The payout is so little that they don't care if you have it sorted by steel, alu, etc.

The chainring is worn, clearly evident if you compare to a new chainring, if a chain going past 0.8% elongation wasn't enough of a reason. I'd say leave the old chain on and ride everything into the ground, including RD pulleys, cause you have to replace everything anyways.

Notice how the pockets on yours lost its U-shape and curves into the tip evenly, from the stretched chain sort of re-sizing it.

 

[Beekeeper]

So chain arrived today (KMC 11) exactly same as the old one which was a touch under 0.75% wear after 1000 miles.

New chain made a right old racket when climbing, almost sounded like a machine gun coming from the small Bosch chainring.

also the other weird thing that happened about 4 times was the chain would not disengage as it travelled around the front sprocket almost as if it was glued to it, causing the chain to jam against the frame a few times. Never happened at speed only happened when I first jump on the bike and get going.

so my questions are this......

1) is the sticky wax they put on the chain causing the chain to stick to the front sprocket?

2). Will the horrid machine gun / ticking noise get better when climbing as it beds in?

 

[Snoozeboy]

So chain arrived today (KMC 11) exactly same as the old one which was a touch under 0.75% wear after 1000 miles.

New chain made a right old racket when climbing, almost sounded like a machine gun coming from the small Bosch chainring.

also the other weird thing that happened about 4 times was the chain would not disengage as it travelled around the front sprocket almost as if it was glued to it, causing the chain to jam against the frame a few times. Never happened at speed only happened when I first jump on the bike and get going.

so my questions are this......

1) is the sticky wax they put on the chain causing the chain to stick to the front sprocket?

2). Will the horrid machine gun / ticking noise get better when climbing as it beds in?

It sounds as though your chainring is worn to the point that it grabs at the chain as it leaves. I had the same problem. Solution was to change the chainring, so I don't know if the noise gets better.

 

[R120]

Is the chainring chewing up the chain stay protector too? Looks like it form the picture? Looks like its a 38t chainring or am I reading the labelling wrong, I dont think they came with that size chain ring?

 

[Beekeeper]

It sounds as though your chainring is worn to the point that it grabs at the chain as it leaves. I had the same problem. Solution was to change the chainring, so I don't know if the noise gets better.

i read that flipping the small Bosch chainring to the other side can help. Worth trying. I’ve also ordered a new chainring (15t) from Trendz just in case.

I’m starting to think that unless you have a really expensive cassette, just run everything into the ground and replace whole lot at once when symptoms show.
A chain for my bike was nearly £20 and Cassette is £45, chainring £15. so why am I creating another problem with things not meshing properly and skipping / jumping and having to deal with annoying noises.
I could get 2000 miles of trouble free drivetrain and then replace the lot for £80

 

[Snoozeboy]

i read that flipping the small Bosch chainring to the other side can help. Worth trying. I’ve also ordered a new chainring (15t) from Trendz just in case.

I’m starting to think that unless you have a really expensive cassette, just run everything into the ground and replace whole lot at once when symptoms show.
A chain for my bike was nearly £20 and Cassette is £45, chainring £15. so why am I creating another problem with things not meshing properly and skipping / jumping and having to deal with annoying noises.
I could get 2000 miles of trouble free drivetrain and then replace the lot for £80

Flipping it may work, but not much point IMO for 15 quid.

I was of the same opinion as you for a while regarding changing chains etc., but I was getting through chains a lot quicker than 2000miles. I didn't know why I was changing a USD50 KMC chain at 0.5 stretch, to save a USD60 cassette (11s SLX 11-46t). But then I discovered USD15 SRAM chains were just the same longevity and smoothness as a KMC chain with "Ebike" written on it.

I should add that it depends on the peculiarities of your situation. There are a lot of hills around here and whenever I use the bike for commuting rather than leisure, I leave it in Turbo. This means that the chain wears quickly, but the wear on the cassette is slow, being spread across all the gears.

Now, I buy the cassette and 3x USD15 chains at the same time. I rotate the chains every 500km and give the drive train a clean at the same time and continue the rotation until the cassette starts skipping. Aside from oiling and the occasional wipe of the chain, this is the only maintenance I do. Wearing the 3 chains and the cassette at the same rate reduces the incompatibility of having differently worn drivetrain items. I should really include 3x chain wheels but haven't, yet. Drivetrain cleanliness puritans will hate me, but I'm happy to put up with non-perfect shifting for less maintenance.

 

[Beekeeper]

Flipping it may work, but not much point IMO for 15 quid.

I was of the same opinion as you for a while regarding changing chains etc., but I was getting through chains a lot quicker than 2000miles. I didn't know why I was changing a USD50 KMC chain at 0.5 stretch, to save a USD60 cassette (11s SLX 11-46t). But then I discovered USD15 SRAM chains were just the same longevity and smoothness as a KMC chain with "Ebike" written on it.

I should add that it depends on the peculiarities of your situation. There are a lot of hills around here and whenever I use the bike for commuting rather than leisure, I leave it in Turbo. This means that the chain wears quickly, but the wear on the cassette is slow, being spread across all the gears.

Now, I buy the cassette and 3x USD15 chains at the same time. I rotate the chains every 500km and give the drive train a clean at the same time and continue the rotation until the cassette starts skipping. Aside from oiling and the occasional wipe of the chain, this is the only maintenance I do. Wearing the 3 chains and the cassette at the same rate reduces the incompatibility of having differently worn drivetrain items. I should really include 3x chain wheels but haven't, yet. Drivetrain cleanliness puritans will hate me, but I'm happy to put up with non-perfect shifting for less maintenance.

interesting. Presumably you have quick links on your chains. If you are swapping the chains around multiple times does this damage the quick links? I use KMC chains