jskash

The gears on my Giant Cypress have been slipping a bit, so I took my bike into the shop today. I was told that the chain was starting to wear out. They said it would be best to not change the chain until the crankset and cassette also need to be changed. That entire process would cost about half of what I paid for the bike. I have already reached over 4,000 miles so far this year. Given the amount I am riding, is it worth replacing the worn out parts on a bike that cost under $400? There is nothing else wrong with the bike and I have upgraded the tires, hand grips, and pedals.

Thanks.

prathmann

Seems like odd advice. My experience has been that chains wear out considerably quicker than the other drive train components. I typically get about 5,000 miles out of a chain, 20,000 miles on a cassette, and the last chain ring I replaced had over 90,000 miles on it (and it was only the most used ring that I replaced, not the whole crankset).

Now if your chain is already very worn then it may be that the cassette has also worn to the point where a new chain will not properly engage the teeth on the sprockets and you'll get much worse skipping with the new chain. What I would do at this point is to buy a new chain and probably also a new cassette - but I'd start by only replacing the chain. If it works ok with the old cassette then all is well for now and you can keep the new cassette for future use. But if you experience bad skipping then replace the cassette as well. I'd be very surprised if you need to worry about the chain rings until you have many more miles on your bike.

This shouldn't cost you all that much. Here's the cassette that comes on the Cypress:
Shimano HG31 Altus 8 Speed Cassette > Components > Drivetrain > Cassettes | Jenson USA
and here's the chain:
KMC Z-72 8 Speed Chain > Components > Drivetrain > Chains | Jenson USA

Ravenhog

4000 miles on a chain? Great job. Personally I change my chains at about 1000 miles no questions asked. Saves my chainrings and cassette from premature wear caused by a worn chain.

If I were you I would change out the chain. If the slipping continues on the rear cassette, will be more apparent on the cog(s) you ride in the most, then change out the cassette. You wouldn't need to purchase a new crankset unless the cranks area damaged. You should be able to replace the worn chainring(s) themselves. All three might not need replacing.

I think this would be better suited in the Mechanic thread, Moderator?

Juha

What everyone else is saying. In my case, the most I've gotten out of a drivetrain is about 12 000 km, didn't replace anything until then. The one before that gave in at maybe 7 000 km, so there's a lot of variance even with the same bike, rider and location.

Also, I'm moving this to Bike Mechanics forum (from Hybrid Bikes).

--Juha, a Forum Mod

hyhuu

OP - What you need is a new shop or just learn how to change the chain by yourself.

Wilfred Laurier

OP - What you need is to not listen to any of the above posters. If you have 4000 miles this year, and presumably some miles in previous years, on your current chain, then it is at least at the point where it should be changed. But since there are symptoms of drivetrain wear (skipping), then the chain is certainly well beyond the point that it can be changed and a new chain will mesh with the old cogs.

So swapping just the chain at this point will almost definitely make the drivetrain into a noisy skipping unridable mess. Your shop is right, and (surprise surprise) internet advice is unreliable.

Usually you can manage with just installing new cassette and chain, but in advanced cases, the teeth on the chainrings will be pretty worn too, and will not work well with a new chain. So, since I don't have the bike in front of me to look (chainring wear is often visible, rear cog wear is often not), I will take the best eveidence available: 4000+ miles, the shop that saw it thought it would not work.

Also please note that the shop didn't try to trick you into buying anything - they told you to hold off buying anything until you can do the full replacement. They have nothing gain by telling a lie like that.

Wilfred Laurier

You are mostly correct, except that you can usually not change individual chainrings on a $400 hybrid. On less expensive bikes, the rings are riveted to the crank.

jskash

I ordered all the parts today from the shop including new break cables. The total came to $113. With labor it will be a bit over $200. I can live with that. Now I know that I need to have the chain looked out every few months for wear.

ksryder

Chain wear tools are inexpensive, just get in the habit of checking the chain once a month. Installing a new chain is one of the easiest DIY mechanic things you can learn to do.

Took me longer than I care to admit to learn that but a $20 chain every few months is much better than replacing cassettes and chainrings every year.

cny-bikeman

Chain wear tools are expensive given that they are not necessary and not terribly accurate unless they are even more expensive. They were originally intended for shop use as a quick way to check multiple bikes. All you need for a more accurate gauge of wear is a good quality ruler that is graduated to at least 16ths of an inch. Go to Sheldon's Chain Maintenance page and see "Measuring Chain Wear." Using a ruler takes maybe a minute.

lolguy

I replaced my cassette and chain at 4,000 miles. Now at 7k, they are worn and ready to be changed again. In reviewing the large chainring, it's quite worn (teeth are smaller and sharp as a knife) and I'm replacing it, too. Since the price of the two rings was not much less than the entire cranket, it and the BB are also being replaced. Basically, the entire drivetrain. It should ride like a new bike once done.

ksryder

Yes a $10 chain checker is way expensive.

prathmann

Well it's $10 more expensive than the yardsticks given away by the local hardware store which work fine for this purpose.

GeneO 

Chain wear tools are also inaccurate giving a false positive. A ruler is much better. Replacing a chain every few months? How many miles is that???

https://pardo.net/bike/pic/fail-004/000.html

ksryder

Christ on a ******* measure it with an electron microscope for all I care the point is check your chain before you wear out your cassette. Are you guys always this pedantic?

ThermionicScott 

BikeForums members will rise to the occasion. I agree that the OP would have come out way ahead even with the "overpriced" chain checker.

GeneO 

It is not pedantic. Most chain wear tools don't work. What do you want me to say. A freaking rigid 12" ruler works well - you don't need a micrometer.

I have used a couple of chain wear tools on a new chain and they indicated it needed replaced!

cny-bikeman

Any tool one does not need and that does not perform it's intended purpose well is expensive.

hyhuu

If the shop had stopped at the chain and cassette then I would have no problem. They also mentioned crankset for crying out loud.

ksryder

Wilfred Laurier

What was your assesment of the chainrings when you examined the bike?

Looigi

It's not the cost of the tool, but the cost of needless premature chain replacement that's expensive. Most all commercial chain checkers are expensive in that they over estimate chain elongation such that you wind up replacing chains more frequently than necessary. Here's an explanation: https://pardo.net/bike/pic/fail-004/000.html

Bike shops like these as they're quick and easy to use and sell more chains.

Wilfred Laurier

+1

Every time I have seen a *new* chain checked with a chain wear checking tool, it indicates at least partly worn. In some cases, new or almost new chains are indicated at or near their suggested replacement point. A 12 inch ruler is a much better tool for the job.

jskash

I had all the new parts installed on the weekend. It is like having a new bike. I had not realized that shifting had gotten so difficult until I rode it after it was fixed. It shifts so smoothly now. Every two months I will have the shop check the chain for wear so I don't repeat the same mistake again.

scott967

Ya I guess it's amazing how nice an in-tune bike can feel.

scott s.
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