Broken chain

[Johan Bornman]

JB' date=' I have been riding DA for most of my life. I heard that Ultegra chains and clusters are harder wearing and therefore last longer than DA. So when I bought my Racing wheels last year I put the DA cluster on my racing wheels and an Ultegra on the training set seeing as I do way more kms on the traingwheels and when the time came for replacing the chain I put an Ultegra on.

 

Price is usually not an issue when replacing components (Ultegra vs DA) by me, I'm just looking for something that will give me good service for the money. What is your opinion on this?

[/quote']

On high-end clusters, the big sprockets are made of titanium. This makes them more expensive, lighter and less durable.

 

For the purpose of this debate, lets focus on the steel sprockets. They're made of carbon steel that's been case hardened, in other words, hardish steel with an even harder shell. It's easy to see when the hard shell has been worn through as the sprockets suddenly starts to wear quickly.

 

Sprockets from the same manufacturer are made of the same steel, received the same hardening process and were stamped on the same machine. The difference (on steel sprockets) lies in the coating (chrome at the high end vs zinc plating on the lower end (which translates to very shiny to mildy shiny and roughish) and the sprocket carrier. In addition to tiitanium bits, high-end sprockets also have carriers designed to minimise the use of steel and put aluminium to good use where it doesn't touch the chain.

 

Expensive sprockets are also drilled to save weight and make them look like value for money. Holes have no functional benefit.

 

Therefore, all being equal, an expensive (steel) sprocket wears as fast as a cheap steel sprocket. The titanium ones are about as durable as butter.

 

All you have to decide is why you'e buying DA and not 105...is it weight or looks. With low weight and good looks come the compromise of titanium.

 

Simply put, strong, light, cheap....choose two.

Johan Bornman2008-05-14 04:11:18

[Johan Bornman]

the sideplate's holw elongates but doesn't change it's diameter!?!?!??? there's a pin in that hole' date=' so when the hole elongates it changes it's form from "perfectly" round to a bit strechted round. since the pin is in there the horizontal hole sides can't just be pulled down and up respectively (unless they deform or cut into the pin). so the inner circumfences of that whole must increase and therefore more play and proneness to brake result.
doesn't it?

(don't jump on me and beat me to death with a not-understanable answer. just questioning your statement and asking for an aswer - sincerely yours!)
[/quote']

 

White men can't jump! You're safe.

 

I should have said it doesn't change diameter ENOUGH AND ON ALL SIDES TO ALLOW THE MUSHOROOM TO ESCAPE.

 

Modern bicycle chains have an enormous amount of side-play. This is designed into the chain so that it can move from sprocket to sprocket via the jockey. If you compare this with a track bicycle chain or lawnmower chain you'll see the difference. A little bit of extra play doesn't matter at all. And yes you are right, a worn chain will have more play, but it doesn't matter and it is not enough to make it more prone to breaking.  The only time you can engineer it so that a little bit of extra play makes gear changes sluggish is by backing off the B-tension screw in the jockey so that the top jockey wheel and sprocket are very, very far from each other. But that's not a realistic scenario.

 

 

 

[Johan Bornman]

A chain when worn also wears side to side when viewing a chain from the top on drivetrain. Therefore means play on chain when shifting from one gear to another. The top pulley's distance from gear is never just 1 pin usually 2-3 pins which means the deviasion from side to side becomes greater and the chain does not engage correctly.

 

As I explained to Mr Legend above, the scenario you pain is correct up to where you argue that shifting is affected. In practice it doesn't change shifting at all. It is easy to demonstrate on a bike strapped into a workstand. This experiment is legitimate since the chain tension on the underside is always slack, whether you're pedaling uphil or just spinning the cranks on a workstand.

 

At the entry end of the sprocket, a worn chain engages perfectly. It only starts to climb the ramp and skip once it rotates into the tension zone, which is the top part of the sprocket. Therefore your statement that it does not engages correctly is not the real scenario.

 

A very worn chain (and therefore unrideable one) won't engage at all, just like you start to describe in your second sentence. But again, that is not the experience on a bicycle because we don't allow our chains to go that far nor do we back off the B-tension srew that much.

 

[Veloce]

I have removed countless chains and never push the original pin back in. This is because whenever I use the chain rivet extractor tool, the little mushroom head prys off and I feel it is unsafe to put it back. Am i doing it wrong, 'cos after all I am the guy that says NEVER use motor oil on your chain because of the grit that manages to stick to it forming a grinding paste.  

[Johan Bornman]

I have removed countless chains and never push the original pin back in. This is because whenever I use the chain rivet extractor tool' date=' the little mushroom head prys off and I feel it is unsafe to put it back. Am i doing it wrong, 'cos after all I am the guy that says NEVER use motor oil on your chain because of the grit that manages to stick to it forming a grinding paste.  

[/quote']

Perhaps you never learnt and practiced the trick.

 

When you push the pin out, you don't push it all the way out. You make sure it doesn't leave the second plate and in fact, it doesn't even go flush with the second place, you try and leave 0.26mm (exactly give or take 1mm) of pin on the inside of the plate. Now you gently force (is that an oxymoron?) the inner link out by bending it sideways.

 

The chain is now separated and you can do whatever it was you separated it for. To replace it, the little piece of pin jutting out on the inside is the perfect guide and helps reduce the need for four hands. Reverse the chain in the chain tool and make sure the outer place pushes against a solid part of the tool. This may not be clear but once you've broken your first tool by getting this wrong, you'll understand.

 

Now push the pin back, until the outside of the pin looks like it is positioned just like the other undisturbed ones. Too far in, and the chain will click-click and break. Not in enough, same story. Run your fingers up and down the chain and see if that link feels just like the others.

 

Changes are that your link will be slightly stiff. Bend it forcefully sideways until that link runs over a screwdriver blade as smoothly as the others.

 

Now oil it with half the components of the grinding paste you mention above.

 

It is best not to try this in the field for the first time. Get an old chain and break and repair it until you can do it with your eyes closed. This skill will come in useful somewhere out there on the road.

 

BTW, I have never had a mushroom head come off on me. How do you manage to do that?

 

 

 

[Veloce]

Its not the entire mushroom head that breaks off, just a little ring of metal comes off as the pin gets pushed through the first sideplate. I never push the pin past the second plate, but when i see this little metal ring lying in the chain tool, get pissed off, push it the entire way out and put a quick link. Probably the best thing to do as it is then a very simple job to clean your chain. I would still like to know how i am getting this wrong...  

[Kranswurm]

Are you guys still trying to fix that blinking chain?

Please go out and buy some pins.They cost stuff all and make it easier.

And the job will get done.

Whew!!!

I suppose its better than that pathetic drivel about porn,avatars,etc,etc,that we are all ignoring and hoping will just go away forever.

[MTBiker]

I bought a new mt bike ,it came with a shimano Hg-73 chain, and on the 3rd ride the chain broke.when it broke the whole link bent sideways like this pic    Then 1 or 2 months later on a long mtb race the chain broke 4 times.

 

I replaced it with a spare HG-53 chain i had and it was fine for a while 5 months later it broke again.

 

 

 

Is this a bad chains or a bad setupMTBiker2008-05-14 08:52:27

[steven]

Our experience with broken chains has been as follows.

1) A new chain pin has to be used every time the chain is split together

   with  the correct chain tool being used.

2) Shifting whilst under load.

3) Incorrect lube and or cleaning agent being used.

4) Bad assembly from either the factory or mechanic or self trained mechanic not reading the instructions supplied with every Shimano product imported thru the correct distribution channels.

5) Mixing and matching Shimano or BBB or Sram components does not help either as Shimano products are designed to work together so that shifting performance, durabilty and reliabilty are ensured from the start.

6) Work at the Cape Epic for 10 days and then you will begin to understand what i am trying to relay. I am not doing stating these facts to promote or advertise Shimano on the web.They are just pure facts.    

RGDS STEVE M

www.coolheat.co.za

[jabbathemutt007]

 

Stay with Shimano as these  components are designed to work 100 % together' date=' mixing and matching is not a solution. I agree with JB as poor shifting and or poor instalation is most probably the cause of your chain breaking.Shimano chains are designed to fail at 9000 Newton Metres of Torque. A small average size motor car only delivers 200 Newton Metres of Torque.

rgds sm

www.coolheat.co.za

 [/quote']

Surely the fact that you sell Shimano has nothing to do with your comment.

 

I never use Campag chains on my road Campag bike or Shimano chains on my MTB. Both suck; Wipperman and/or SRam chains work much better. And having a chain with a master link makes cleaning your drivetrain much easier. And you can use most Shimano 10sp compatible chains on a Campag 10sp with no problems, although I doubt if the vice-versa applies.

[Johan Bornman]

I bought a new mt bike ' date='it came with a shimano Hg-73 chain, and on the 3rd ride the chain broke.when it broke the whole link bent sideways like this pic    Then 1 or 2 months later on a long mtb race the chain broke 4 times.
I replaced it with a spare HG-53 chain i had and it was fine for a while 5 months later it broke again.

Is this a bad chains or a bad setup[/quote']

 

Neither, it is due to bad shifting technique.

 

The reason I argue that line is tht in a bad setup, you'll only find one bad link - the one you spliced.

 

If there are three or four other breaks at different places, you need to modify your shifting technique. No chain is that faulty.

 

You may also need some new friends. Continuous bad shifting usually make your friends cringe and the good ones will tell you that you're a dork and give you some advice. Bad friends will just stop riding with you, thinking that you're chain-jinxed and they cannot afford the downtime on each ride.

 

[Dirtbreath]

Johan and all, thanks for this interesting thread.

What constitutes poor shifting technique?

 

An example. You are on your mtb coming down a steep hill in your big chain ring and small sprocket. You turn left up a short but steep uphill and NEED your Granny Gear.

 

You have 5m to get down. What is the best way to make this chain.

[GoLefty!!]

Look further ahead than your front tyre..

 

I have never been surprised by a hill. It's not like it jumped out from behind some fynbos or something and shouted "Supplies".

Hills are hills and relatively they don't move much in our livetime unless we experience an Earth Crust displacement event.; if this happens your problems are bigger than changing gears or breaking a chain.

 

But if you are surprised by that hill that jumped across the trail, then click the paddle one clisk at a time.

In this situation you really want a Rapid Rise rear derailleur. I won't allow you to break a chain. They are that well trained

[GoLefty!!]

I have removed countless chains and never push the original pin back in. This is because whenever I use the chain rivet extractor tool' date=' the little mushroom head prys off and I feel it is unsafe to put it back. Am i doing it wrong, 'cos after all I am the guy that says NEVER use motor oil on your chain because of the grit that manages to stick to it forming a grinding paste.  

[/quote']

Perhaps you never learnt and practiced the trick.

 

When you push the pin out, you don't push it all the way out. You make sure it doesn't leave the second plate and in fact, it doesn't even go flush with the second place, you try and leave 0.26mm (exactly give or take 1mm) of pin on the inside of the plate. Now you gently force (is that an oxymoron?) the inner link out by bending it sideways.

 

The chain is now separated and you can do whatever it was you separated it for. To replace it, the little piece of pin jutting out on the inside is the perfect guide and helps reduce the need for four hands. Reverse the chain in the chain tool and make sure the outer place pushes against a solid part of the tool. This may not be clear but once you've broken your first tool by getting this wrong, you'll understand.

 

Now push the pin back, until the outside of the pin looks like it is positioned just like the other undisturbed ones. Too far in, and the chain will click-click and break. Not in enough, same story. Run your fingers up and down the chain and see if that link feels just like the others.

 

Changes are that your link will be slightly stiff. Bend it forcefully sideways until that link runs over a screwdriver blade as smoothly as the others.

 

Now oil it with half the components of the grinding paste you mention above.

 

It is best not to try this in the field for the first time. Get an old chain and break and repair it until you can do it with your eyes closed. This skill will come in useful somewhere out there on the road.

 

BTW, I have never had a mushroom head come off on me. How do you manage to do that?

 

 

 

 

 

 

The mushroom head does not come off the pin. That ring of material is from the link plate! If you reuse that pin then you make the hole in the link plate bigger weakening the join in the chain. Hence it is safer to use the re-inforced pins supplied with the chain.

 

I too was in the habit of pushing the original pin back in. Then I started having chain failures. The chain failures stopped after I used the supplied pin. It has a slightly larger diameter than the other pins so that the interference is maximised.

On a road bike it's less prevalent but on the MTB it happens often.

 

Use the reinforced pin

[Sammajoor]

Seems this is a Sh1tmano problem David Millar had the same problem in the Giro.

[MintSauce]

Look further ahead than your front tyre..

 

I have never been surprised by a hill. It's not like it jumped out from behind some fynbos or something and shouted "Supplies".

Hills are hills and relatively they don't move much in our livetime unless we experience an Earth Crust displacement event.; if this happens your problems are bigger than changing gears or breaking a chain.

 

But if you are surprised by that hill that jumped across the trail' date=' then click the paddle one clisk at a time.

In this situation you really want a Rapid Rise rear derailleur. I won't allow you to break a chain. They are that well trained

[/quote']

 

 

Aaaah that's a funny post....thanks GL