Chain Life

Riatsala

My chain broke last week after 2500 miles /7 months of commuter use. Evans told me you should replace the chain every 6 months to save damgae to the other more expensive drivetrain components. Are they just punting for business or do they have a point?

Wooliferkins

A bit of both. I'd be happy with 2500+ out of a chain. It's a bit of a moveable feast depending on an individuals riding style, strength, maintenance habits.

owenlars

1500 miles I reckon, or you can buy a gauge and measure it.

The chain, chainset and cassette all wear together (obviously) and as the rollers in the chain wear the effective gap between rollers increases and wears the teeth on the chainset and cassette accordingly.

You can see this on the teeth as they begin to have a shark's fin like appearance.

If you don't change the chain you don't notice anything until something else happpens such as the chain breaking. So you can leave everything working together for a lot longer than 1500 miles however when it goes you will have to replace the lot.

However if you leave it too long and then replace the chain and not the cassette you will probably find that a new chain skips on the old casstte because it has worn to fit the old chain and the new chain rollers slide up the old teeth. The only solution is a new cassette. The same happens to the chainrings, only slower.

If you change when the wear indicator shows 0.75% wear or around 1500 milesish on a road bike you will get something like three or four chains per cassette. I guess you can do the sums.

solsurf

I replace my chain every 1500 miles, its cheap and quick and saves money by not wearing out the rest of my kit.

Changing a chain depends on loads of different things, like weather, road conditions, the way you ride, how you look after etc. for me I figure 1500 miles works for me.

Chain Reaction had a great offer recently on Mavic chains so I stocked up for the next 4500 miles.

So what I'm saying is I think the evans people were giving good advice.

Riatsala

Well that seems pretty conclusive. Thanks everyone I'll keep a close eye on my milage from now on

iain_j

Mine (9 speed Shimano) has done over 2 years and over 5000 miles. Hasn't been neglected maintenance-wise but hasn't had the best life. Still runs smoothly tho.

iain_j

Or maybe not.

Just checked my chain by the 12 links = 12" method and it's stretched 1/8".

More bike spends

owenlars

iain_j wrote:

Or maybe not.

Just checked my chain by the 12 links = 12" method and it's stretched 1/8".

More bike spends

I'd leave it till something gives and then replace the lot. After 5000 miles your chainring(s) may well be up for grabs as well.

iain_j

I've never been shopping for chains and cassettes before so I'm a bit bewildered by what's available (on wiggle at least). Last time I needed them replacing, on my old bike, the whole lot was stuffed after the rear mech fell into the spokes, so I let the bike shop do the lot.

What's the difference, say, between a Shimano HG50 and a HG80 cassette, both 9-speed, other than the price? Would a KMC chain run on any of them, as long as it's a 9-speed? Do KMC chains come with quick-links or would I have to buy one separately if I wanted that luxury?

daccordimark

Wow, changing a chain every 1500 miles!!

I used to make mine last all year on my commuter/training bike (approx 10000 miles). Then I would change the chain, the inner ring and the 2 cogs on the freewheel that had worn out. What I would actually do is cascade the barely worn ones from my racing bike down to the trainer and buy nice new ones for the racing machine. No idea how much that would have cost back then but probably less than 6 chains.

I don't ride that much anymore so it will take 5 months to get to chain change time at 1500 miles. If I ask whether you can get indivdual sprockets for cassettes will you all laugh at the old timer? If you can't then I can see why changing the chain early is a damn good idea.

MrChuck

Also bear in mind that winter is hard on drivetrains and this has been a bad one. Evans have a point in that changing the chain at the right time can prolong the life of other, more expensive parts but still, 1500 miles doesn't seem that much. Conditions play a big part though.

owenlars

daccordimark wrote:

Wow, changing a chain every 1500 miles!!

I think that's the point, you left it for a year and 10000 miles and then changed everything. If you'd replaced a chain after 5000 miles you would have also had to replace the cogs. You also did it in a way that suited you by using old racing stuff and changing individual cogs. Very often two cogs worn out means a whole new cassette and I have renewed a whole triple crankset that was cheaper than buying two new chainrings. Depends obviously what you have on the bike.

What would 6 chains cost nowadays 60 quid or so for bog standard KMC or similar? A highish end cassette is £50-£100 so it is all a balancing act.

morxy

Buy a Chain Wear Indicator. It detects whether your chain has stretched by 0.75% or 1%.

When a chain has stretched by 0.75% you should replace it. Historically, in my case, chains reach this stage after 2200-2400 miles of riding.

If you leave a chain in place till it's stretched by 1%, it may no longer be adequate to just replace the chain. You may have to replace the cassette and possibly chainrings too.

If you replace your chain early, when you first detect a 0.75% stretch, I think your cassette will last the lifetime of 3 chains? (I'm sure I read that somewhere?) So if I average 2300 miles per chain before 0.75% I can expect a 6900 mile lifespan on the cassette.

iain_j

morxy wrote:

Buy a Chain Wear Indicator

Done. Curse this forum making me spend so much money :P

Riatsala

I always wondered why people bothered with measuring chain wear. Now I know they weren't being anoraks it can actual save money and breakdowns. Thans everyone for your feedback

MrChuck

morxy wrote:

If you replace your chain early, when you first detect a 0.75% stretch, I think your cassette will last the lifetime of 3 chains? (I'm sure I read that somewhere?) So if I average 2300 miles per chain before 0.75% I can expect a 6900 mile lifespan on the cassette.

That's more or less my experience on my mountain bike. I put a couple of new ones on the old cassette when the old ones got to .75 and they worked fine. Last one I put on didn't run well so I put the old one back on and am running the whole lot into the ground now before replacing everything.

mmacavity

http://www.highpath.net/
"depending on what system you have (7,8,9,10,11speed). ..., for long-term reliability, the fewer you fit the better since, the more sprockets you use, the more your chain will be forced to bend sideways and the faster it will wear out. And a worn chain will quickly wear your sprockets and chainrings too. Cyclists who use properly setup hub gears, with just one sprocket and a 1/8" bushed chain, don't suffer from this problem and their equipment tends to last much longer."
"
Any current 3/32" chain can be used with gears up to 8 speed but narrower ones are needed for 9, 10 and 11 speeds. Modern chains are more flexible than the old 'bushed' types, in order to cope with the greater number of rear sprockets that have become fashionable but, unfortuantely, they don't last as long and have to be replaced far more regularly.

Replace a chain when it has stretched by 1% (ie. when 24 links measure 308 mm or more between centres). And always replace your chain whenever you install a new chainring or sprocket"

iain_j

OK, my chain gauge arrived from CRC today and my chain's 1% worn. I take it that means new chain and cassette, but how about chainrings? How do I tell if they need replacing? I imagine I can just replace the rings rather than the whole chainset. It's a triple, and the granny ring hasn't had all that much use.

stickman

I change my chain at 1.0, I used to at 0.75 but after accidently leaving it longer one time I found that 1.0 is no problem.

andyrm

i run a very non-scientific approach on my MTB of changing the chain every 20 rides which is an average of every 2 months. I could probably get away with more, but £20 every two months seems lots better than the horrible gear skipping, wallet bruising feeling that comes when you've changed a chain a bit late and killed a cassette, or more likely just one sprocket on a cassette. It's an easy method to remember, I just check my calendar on the wall and job done....

andrew_s

stickman wrote:

I change my chain at 1.0, I used to at 0.75 but after accidently leaving it longer one time I found that 1.0 is no problem.

If you leave it until 1%, the (old) cassette will be worn enough that the wear on the new chain will be faster than it would be on a new cassette.

The normal options with chain wear are:-
a) Just leave everything on until it stops working properly. You'll then have to buy a new cassette as well as chain, and perhaps a new chainring or two as well. I've found I have to swap middle & outer chainrings every other chain.
b) Put a new chain on before the chain has stretched enough to wear the cassette too much. Your cassette should last 4 chains or so, and the chainrings for at least 8 chains
c) Buy 3 or 4 chains and use them in rotation, swapping every 400 miles/2 weeks, and just keep on swapping chains until your transmission stops working properly. You'll have to buy a new cassette, another set of chains, and possibly chainrings.

What works out cheapest will depend on the relative cost of your chains, cassettes and chainrings.
e.g if you use HG50 cassettes, £19 and PC991 chains £23, you'd be daft to get a new chain to avoid wearing the cassette too much.

When I've worked it out using my normal component choice and my mileages, I've found that (b) is the most expensive, and that (c) is the cheapest. (b) is expensive because you are wasting more money throwing away part used chains than you are saving in increased cassette life.

stickman

Something for people to think about there but in my case my main bikes are two with hub gears and a singlespeed so it's only a s/s freewheel or single cog to replace if I ever need to, I buy Taya chains that are £6.