Need to replace chain and cassette after a year

zagmund

Casual cyclist - 20km a day to work, 3 days a week. I got it some time last year, so let's say it's 12-18 months old. Mrs Zag left the bike in for a bit of a tune-up and the guy says that the chain cassette (not sure what the cassette is by the way) need to be replaced. Cost is estimated at ~€60, fitted.

Here's the pitch - the last bike I had lasted me for 15 years without having to have this sort of work done on it. I don't mind paying money to fix something that's broken or will break, but I don't understand what changed in the way I cycle or what caused this sort of wear.

Is there a simple/common explanation for what would cause the cassette to need to be replaced in this short a time frame ?

Sorry if this is slightly unclear, but I'm hoping that someone here will reckognise the scenario and have some wise comments for me.

z

07Lapierre

It is recommended that if a cassette (the sprockets on the rear wheel) is worn and needs to be replaced, then the chain should also be replaced.
A worn chain will not "sit" correctly on a new cassette.

What kind of bike is it? did you buy it new or second hand?

zagmund

It's a Trek 7.2 or 7.3 (or 7.something), bought new from a dealer.

z

canhascheez

did you clean/lube the chain every couple of hundred km?

zagmund

I oiled it every few months which would translate to every few hundred (well, maybe ~1,000) kms at the rate I cycle. I didn't clean it - there didn't look like anything to clean.

On my old bike (a Raleigh city something) I used to remove large amounts of gunk from between the sprockets every year or two by sticking in the blade of a screwdriver and rotating. Not very scientific I'm sure, but it worked. With this bike there didn't look like there was any gunk.

z

Lemag

If used incorrectly, a chain and cassette can wear quite quickly. No one here can really say what the story is with your situation as we can't inspect them. There is one very easy test which you could do with a ruler to check to see if your chain has been stretched. I can't remember the precise details of it but you could google it.

Explosive_Cornflake

It's not unreasonable, especially as you never cleaned the chain. Grit builds up on the chain and wears the sprockets. As mention, you'd normally replace the chain and cassette together if the chain is badly worn. Chain wear can be checked with a ruler, or most shops will use the park tool chain tool which is reliable also.

The chain on your new bike is almost defiantly thinner than your old Raleigh one so it will wear faster.

60 euro fitted is not bad.

deandean

Zag are you having problems with it? If it is cycling OK and changing gears OK I'd say just leave well alone. You'll probably get loads more use out of it.

BUT when my stuff is well worn I replace everything: chainwheel, cassette, chain, and derailleur wheels. I've always had trouble when replacing things bit by bit.

Get a chain cleaning&lube gizmo from Lidlaldi next time they're in, chain wear is mostly from getting dirt in the chain, = grinding paste.

Morgan

zagmund wrote: »

Casual cyclist - 20km a day to work, 3 days a week. I got it some time last year, so let's say it's 12-18 months old. Mrs Zag left the bike in for a bit of a tune-up and the guy says that the chain cassette (not sure what the cassette is by the way) need to be replaced. Cost is estimated at ~€60, fitted.

If you can still pedal the bike and the gears still shift then it doesn't HAVE to be replaced. Personally, if it's just a commuter, I'd leave the chain and cassette in place until they're literally worn out.

ednwireland

deandean wrote: »

Zag are you having problems with it? If it is cycling OK and changing gears OK I'd say just leave well alone. You'll probably get loads more use out of it.

BUT when my stuff is well worn I replace everything: chainwheel, cassette, chain, and derailleur wheels. I've always had trouble when replacing things bit by bit.

Get a chain cleaning&lube gizmo from Lidlaldi next time they're in, chain wear is mostly from getting dirt in the chain, = grinding paste.

my commuter is a bit like that i dont clean it vey often and let stuff go on it BUT its 7 speed, my 10 speed bike wore out the chain and it started jumping off the front rings, my 9 speed mtb hasnt been used enough to wear out the chain

07Lapierre

deandean wrote: »

Zag are you having problems with it? If it is cycling OK and changing gears OK I'd say just leave well alone. You'll probably get loads more use out of it.

BUT when my stuff is well worn I replace everything: chainwheel, cassette, chain, and derailleur wheels. I've always had trouble when replacing things bit by bit.

Get a chain cleaning&lube gizmo from Lidlaldi next time they're in, chain wear is mostly from getting dirt in the chain, = grinding paste.

This is probably the best advise,. As you say yourself...your a casual cyclist, not doing huge milage. "If its not broken, don't fix it".

petethedrummer

zagmund wrote: »

Here's the pitch - the last bike I had lasted me for 15 years without having to have this sort of work done on it.

I remember bikes lasting longer when I was younger, but I didn't nearly do the same mileage. Were you doing the same distances on your old bike?

Al Wright

If the bike is a 'run of the mill' hybrid, pedalling and gear change ok, then I'd recommend leave it alone, continue to oil the chain as before etc.
On my hybrid I run the chain to the last, usually 6000 miles(2 1/2 years). Some of the chain rollers have even worn through by then. Last time, an 8 speed Sachs chain cost Euro 16.- and 8 speed cassette Euro 25 (fitting them myself)
On my road bike its a different story as the alu chainset itself is worth a few hundred euro and the cassette itself ca Eu 95.-. Here I regularly check the chain for stretch and replace when it's length increases between 0.7 and 1%. The chain lasts just over 3000 miles and I usually get by with one cassette for 3 chains

MungoMan

Why would you want to replace a casette and/or chain ?

I'm guessing that the answer is the moment it that either start to malfunction.........(the op didn't say that the casette was malfunctioning, I wonder why the bike shop would want to replace it ?)

What undesirable behaviour does a malfunctioning chain/casette show?

Personally, I cycle maybe 100km a week, and I never replace anything (unless it's broken).
I have had a new casette a couple of times, but only because my rear wheel was stolen.

papac

zagmund wrote: »

Here's the pitch - the last bike I had lasted me for 15 years without having to have this sort of work done on it. I don't mind paying money to fix something that's broken or will break, but I don't understand what changed in the way I cycle or what caused this sort of wear.

Is there a simple/common explanation for what would cause the cassette to need to be replaced in this short a time frame ?



z

Modern lightweight bikes have traded durability for weight saving and more gears. They bikes are nicer to ride but they do wear out the drivetrain faster and the drivetrains are more expensive.

Cleaning and lubing the chain more regularly helps reduce the expense.
60 euros fitted is an ok price and is not bad value for a year or so's commuting imo.

http://sheldonbrown.com/gearing/index.html

tomasrojo

Sheldon also recommends mudflaps. I know people don't like the look of them, but the chain lasts way longer when the water falling on it is merely rain, rather than rain and muddy water.

mfdc

MungoMan wrote: »

Why would you want to replace a casette and/or chain ?

As you do more distance, the chain begins to wear down. If you don't replace it soon enough, it will start to wear the cassette down aswell. If this happens and you just replace the chain, then the new chain will slip since the cassette has worn to match the shape of the old chain.

I had this happen the first time I changed my chain a few years ago - was like something from a cartoon when I tried to pull away from my first set of lights. Horrible grinding noise, cranks spinning away and no forward movement. Had to proceed into work in the smallest cog at the back, since it was the only one not worn.

So if the chain and cassette wear together, why replace them at all? They'll keep on working together fine, but as the chain wears more and more it gets weaker and it becomes far more likely to snap. Nothing worse than having a chain snap in the middle of nowhere. You might go ages on an old chain and get lucky, but why take the risk? The tool to check wear is cheap, and it only takes 2 minutes to check once a month. I've only needed to change my chain once a year, so it's not that expensive overall - have had my chain snap before and to me it's worth it!

zagmund

Thanks for all the feedback. It turns out that Mrs Zag got it replaced on Friday anyway, before I had a chance to read most of this so it's a done deal at this stage.

In usage terms it wasn't slipping or groaning or otherwise complaining when changing, so I think it fitted into the "not broken, don't fix" grouping. I'm not an expert so I can't be sure that it wasn't actually worn unduly, but it's done now. I'll know for next time.

z

tomasrojo

mfdc wrote: »

The tool to check wear is cheap

Even cheaper is to find an old retractable tape measure and snip off twelve inches (from somewhere other than the very start with the right-angled bit).

Discussed before, here:
http://www.boards.ie/vbulletin/showthread.php?t=2056028279

bedirect

you could be using the hight sprocket on the front and the hight sprocket on the rear, the chain is not in line, so it causes more wear. stay on the small sprocket on the front unless going down hill

zagmund

First spin out on the bike since the stuff was replaced. While I wasn't experiencing any problem getting in to gear or problems remaining in gear before, I did notice that the change is much smoother now.

There used to be a lot more noise when changing - it didn't seem bad and everything went into place pretty smoothly from my perspective, but it is in a whole different class now. No longer can I alert people that I'm coming up behind them (on a shared cycle/pedestrian route) just by changing gears.

So - it seems that the old equipment was worn alright. Whether or not it needed to be replaced is up for debate, but I'm happy enough now with my quiet gear change.

z