chain and cassette wear

templer27

Have a park tool that shows my chain is almost almost 100% worn.My chain has never slipped once and my cassette looks almost new.Will I have to get a new cassette?

I really don't know how many miles I have done,its not more than 2000 miles at the very most.Seems like maybe I could get more miles out of it.I am really a novice still and don't know much about bike maintenance.

Come to think about it its more like 1500 miles at most.I am a heavy guy almost 15 1/2 stone so that I presume would have a bearing on chain wear.

paddymacsporran

If the chain is worn, you'd better replace it before it mashes the cassette. You will know if the cassette is worn when you fit a new chain, as it will jump all over the place. Some brands of chain wear quicker than others. 1500 miles isn't that 'out there' to be honest, I've heard of KMC chains wearing quickly, Shimano arent as durable as campag and sram (both the latter are made by sram apparently)

Keeping the chain clean and well lubed is vitally important in getting good mileage, I replace the chain on both my bikes every year and have never had to replace a cassette, I did near 10,000k this year (so far!) Make sure you don't stretch the chain by using the big ring on the front and the small cog on the back and vice-versa. If you spin lower gears it eases chain wear too.

TheBlaaMan

paddymacsporran wrote: »

Make sure you don't stretch the chain by using the big ring on the front and the small cog on the back and vice-versa.

Eh...?

Maybe I'm a numpty, but shouldn't that be t'other way around? (...big back and front, or small back and front)

templer27

Found the Sheldon Brown site first time ever.He recommends measuring from centre of one of the rivets in the chain.Then go 12" along to the to the centre of that rivet.If its 1/16 of an inch out you are ok,but replace the chain before it goes out to 1/8 of an inch.

I have just done this and my measurement is just under the 1/16.So maybe I will be ok,i'll measure again tomorrow just to be sure.I really don't know how accurate this is,but Mr Brown seems to know what he is talking about.Its a very interesting web site lots of useful information,so glad I stumbled across it.

tomasrojo

The Sheldon advice is good. A steel ruler or steel measuring tape is quite a good way of determining whether the chain has worn. I like the images on this site:

http://www.kronowit.com/bicycling/chainstretch.html

tomasrojo

I think he made a slight mistake in what rivet of the link should be at the 13" mark though. It should be the leftmost rivet, not the rightmost, I think?

Single Malt

paddymacsporran wrote: »

If the chain is worn, you'd better replace it before it mashes the cassette. You will know if the cassette is worn when you fit a new chain, as it will jump all over the place. Some brands of chain wear quicker than others. 1500 miles isn't that 'out there' to be honest, I've heard of KMC chains wearing quickly, Shimano arent as durable as campag and sram (both the latter are made by sram apparently)

Keeping the chain clean and well lubed is vitally important in getting good mileage, I replace the chain on both my bikes every year and have never had to replace a cassette, I did near 10,000k this year (so far!) Make sure you don't stretch the chain by using the big ring on the front and the small cog on the back and vice-versa. If you spin lower gears it eases chain wear too.

That I want referenced. Campy manufacture their own to my knowledge since 10s came out. Campy used Sachs chains pre 10s (the 7/8s 7.2mm wide powerchain worked perfect with 9s campy

Civilian_Target

I wore though my Shimano 9-speed chain in 2,500 miles so badly that the cassette had to go too, so yes, it's easily possible!

Canis Lupus

TheBlaaMan wrote: »

Eh...?

Maybe I'm a numpty, but shouldn't that be t'other way around? (...big back and front, or small back and front)

I'm a touch hungover but no. Essentially you try and avoid from making the chain go...diagonal so: big front small back and vice versa.

cython

Canis Lupus wrote: »

I'm a touch hungover but no. Essentially you try and avoid from making the chain go...diagonal so: big front small back and vice versa.

By that logic you would never use the small sprocket on the back, as with the big chainring and small sprocket both being the rightmost options, surely that is the way to keep the chain straightest when using the small sprocket? Diagonal would be big front-big back, as you have rightmost driving leftmost.....

Lumen

cython wrote: »

By that logic you would never use the small sprocket on the back, as with the big chainring and small sprocket both being the rightmost options, surely that is the way to keep the chain straightest when using the small sprocket? Diagonal would be big front-big back, as you have rightmost driving leftmost.....

No.

doozerie

I'm guessing here that the confusion is arising from the slightly ambiguous meanings of "small" and "big" when talking about gears. Big [chainring] front and small [sprocket] back = okay, no cross-chaining. Big [gear] front (= big chainring) and small [gear] back (= big sprocket) = crossed chain.

...or someone is on drugs. Possibly me.

wayne0308

doozerie wrote: »

I'm guessing here that the confusion is arising from the slightly ambiguous meanings of "small" and "big" when talking about gears. Big [chainring] front and small [sprocket] back = okay, no cross-chaining. Big [gear] front (= big chainring) and small [gear] back (= big sprocket) = crossed chain.

...or someone is on drugs. Possibly me.

That makes sense to me. With most front derailleurs, the chain would be rubbing heavily off the front derailleur cage if you were in the big chainring (one with most teeth) and in the cog with the most teeth on the back.

cython

wayne0308 wrote: »

That makes sense to me. With most front derailleurs, the chain would be rubbing heavily off the front derailleur cage if you were in the big chainring (one with most teeth) and in the cog with the most teeth on the back.

Yeah, that was the point I was trying to make, but as pointed out there may have been some confusion over exact terms. I was trying to describe the actual physical appearance of the chainrings/sprockets when saying big and small.

Canis Lupus

cython wrote: »

By that logic you would never use the small sprocket on the back, as with the big chainring and small sprocket both being the rightmost options, surely that is the way to keep the chain straightest when using the small sprocket? Diagonal would be big front-big back, as you have rightmost driving leftmost.....

We both have it right it's just how we phrased it. Maybe we should use diagrams, small words and high use of primary colors next time

Lusk Doyle

This seems silly to me. What then, is the point of having so many gears, if they are not meant to be used? I'm sure that no person stays in one gear constantly on such a setup. That's like telling someone not to walk in one section on the carpet because it will wear it out more than the other parts! If its the way then it will be used more! The same applies to the chain - if the circumstances demand it then it will be used in that way.

If it wears, it wears. Use it, change it if necessary. Done.

doozerie

@Lusk Doyle, You lose only a few gears (at least 2 on a double-chainring, at least 4 on a triple chainring, but the number really depends on how much chain crossing you are happy to live with). And wearing parts out is only part of the concern, the biggest concern is that you are overly stressing the chain when crossing it and increasing the risk of the chain snapping.

Canis Lupus

Lusk Doyle wrote: »

This seems silly to me. What then, is the point of having so many gears, if they are not meant to be used? I'm sure that no person stays in one gear constantly on such a setup. That's like telling someone not to walk in one section on the carpet because it will wear it out more than the other parts! If its the way then it will be used more! The same applies to the chain - if the circumstances demand it then it will be used in that way.

If it wears, it wears. Use it, change it if necessary. Done.

lol, I'm so bad at maintaining my bike that alot of my gears slip through cassette and chain wear. At the mo I use one gear which allows an easy start and a reasonable top spinning speed. It being Winter I'll probably have to finally get my finger out and replace them soon.

Lusk Doyle

doozerie wrote: »

@Lusk Doyle, You lose only a few gears (at least 2 on a double-chainring, at least 4 on a triple chainring, but the number really depends on how much chain crossing you are happy to live with). And wearing parts out is only part of the concern, the biggest concern is that you are overly stressing the chain when crossing it and increasing the risk of the chain snapping.

I should probably stop using 5th gear in my car too so....:P

doozerie

Lusk Doyle wrote:

I should probably stop using 5th gear in my car too so....

I don't see the link (no pun intended) here. A bike's gears are a compromise and you'll find that several of the gears are probably already the same (or close enough to make no difference) anyway so while you might think you have 18, 20, 22, 27, or whatever number, different gear ratios, in reality you most likely have a few less than that. Knocking out those that cause excessive chain cross reduces that number further.

In practice you can cross your chain by a lot and get away with it, but every time you put pressure on the pedal you have to bear in mind that you are stressing the chain in a direction it is not designed for and the risk of popping off a side plate (= broken chain) is significant. And when a chain braaks it is usually when there is a lot of pressure being applied to one of the pedals, which is also when the consequences of a complete loss of resistance against your foot are potentially quite serious.

Lusk Doyle

@ doozerie

The point of the joke was that if I stop using 5th gear it cuts down on wear and tear for the clutch, accelerator, gear box, etc...

Gears are there to be used. They are mechanical and moving parts which by nature wear down and require replacement from time to time.

I just can't understand why people would seem to go out of their way to protect the chain esp when it's cheap to fix!

Anyway, that's just my 2 cents. You guys think one way - I think another.

tomasrojo

Of course, it's entirely up to you how you use your own property. But cross-chaining is of no benefit (you can get the same gearing by moving to a different chainring and sprocket), is inefficient and is bad for both the chain and sprockets. The third reason is important, because while the chain is inexpensive to replace, the sprockets are not.

http://www.sheldonbrown.com/gears.html

Try to avoid the gears that make the chain cross over at an extreme angle. These "criss-cross" gears are bad for the chain and sprockets. Especially bad is to combine the inside (small) front sprocket with the outside (small) rear sprocket. This noisy, inefficient gear causes the chain to wear out prematurely.

Mechanical mechanisms sometimes have redundancy built in. Derailleur gears are one such mechanism. 3 chain rings x 8 sprockets = 24 gears, but not 24 unique gears. There is considerable redundancy.

doozerie

Lusk Doyle wrote:

Gears are there to be used. They are mechanical and moving parts which by nature wear down and require replacement from time to time.

I just can't understand why people would seem to go out of their way to protect the chain esp when it's cheap to fix!

It's obviously your choice whether you use cross-chained gears or not. But the same gear ratios are quite possibly already available to you without cross-chaining so you are unlikely to be gaining any extra gears by doing so. And as to whether it is cheap or not, tomasrojo covers that in his post above - if you routinely cross-chain it is not as cheap as just replacing a chain.

Factor in the increased risk of breaking a chain, or even just the increased risk of the chain jumping when pushing hard which can be nearly as detrimental to your health, and there is every reason to actively avoid cross-chaining. Besides, avoiding cross-chaining is simple anyway, it's certainly a lot less effort than other basic and sensible precautions such as ensuring your tyres are adequately inflated, ensuring your brakes are properly adjusted, etc. But, each to their own.

paddymacsporran

I keep my chain clean, lubed, and change it every year. Never had an issue with casette wear as a result. Prevention is better than cure in my eyes.

This is what accelerates chain wear - riding with the chain on big ring to big sprocket or small to small, apologies if I caused confusion earlier.......Scroll to the bottom of the link for the diagram and it should be clear.

http://www.parktool.com/blog/repair-help/chain-line