spelger

My chain has worn out. normally i would have this done at an LBS but i like to learn how to be self sufficient. Other than chain, what else do i need to make the swap myself? my ride is an 8 speed with a shimano cassette on a trainer and an sram on the ride. current chain behaves well on both. I have heard that i should replace like chain with like.

other than chain, how about tools? i do have a chain removal tool that i have never used before and some funky looking pins in the kit (all 20+ years old). i've heard about power lock, speed lock, speed link, quick link...

shimano, kmc, and sram chains...

Iride01 

If your current chain behaves well then what do you base it being worn out on?

Some of the chain checker tools can be hard to use or easy to misunderstand how to use them. There are also some common ones that for some types of wear will indicate a bad chain when it's really not bad.

spelger

I used a 12" rule to measure 12 links and came up > 1/8" short of 12". I seem to recall reading that 1/8" is a good indicator of a worn chain.

Iride01 

Short? You mean longer don't you?

spelger

ahh, right. measured yesterday. enjoying the day today with some homebrew.

cheers!

TakingMyTime

If your current chain does not have some sort of quick link you'll need your chain tool to pop a rivet on the old chain in order to take it off. When you size the new chain you may need that tool again to remove a link or two before you insert the quick link. That's about it. They do sell quick link tools that make installing and removing a little easier, but they're not usually required.

dsbrantjr

Of you have let your chain become that worn you may find that the new chain will skip on the also-worn cassette. Hopefully your chainrings will not be worn as well.

Iride01 

If you measured it with a ruler......... then good. Although it might still work well, if it is that strectched, you probably should replace it. That much and it's likely already worn on the rear and front gears.

However, I'm always in favor of try it and see. You'll know soon if it begins to not run correctly if you need to replace the front, rear or both. If the instructions in your chain tool box aren't enough, I'd go to youtube and search for changing a tire chain. The youtube vids made by Park Tool are usually pretty good so watch those. And any that are from actual chain mfrs should be good too. Others, might give you some other insights, even if it's that they botch it up because they are just making vids without adequate skill or knowledge.

Your chain tool kit might have various size pins for different size chains. So make sure you get the right pin. Might be a sizing diagram on the instructions. Same for quick links or their equivalent.

Replacement chains from KMC and Shimano in the 10 and 11 sizes usually come with a quick link or at least a pin. Don't know for certain how well they do this for chains for smaller cassettes and freewheels as I've not used one in a very long time.

If you bought the same cheap chain breaker tool I did, then it might break the first use. So be ready for that. I still just use a small punch and hammer with a heavy piece of steel with a small hole as a backer to get my chains apart. But I'm very old school on that and it does take some finesse developed over years to hold it all properly.

Size your new chain to the old chain. If you have issue shifting it might just be slight tweaks of the adjustment screws, not the limit screws. However if the chain doesn't stay on cogs or rings. Or it skips on the cogs or rings, then you might need to replace them too.

Some replace them anytime they replace a chain. And that's fine if you are a high mileage rider and go through a chain every year. Or it just make you feel good to have done so. I just believe that most preventative maintenance cost more than wait till it breaks. And why stop at cassettes and chain rings. Shoot just replace the whole bike every time you need a chain. <grin> But while I poke fun at some that claim you must replace cogs too, you just have to decide for yourself what works for you.

Bill Kapaun

If I have the chain off the bike, I measure a 3' section.
It gives 3X the resolution.
I use the 1" & 37" marks to avoid errors introduced by the hook.

MudPie

No need to worry about brand compatibility. SRAM/Shimano/KMC components play well together. On my road bike, I have Shimano chainring, KMC chain and SRAM cassette.

Personally, I like the SRAM chains for 8 & 9 speed. These chains come with the Powerlink, which is a reusable masterlink you can disassemble and assemble with your fingers. It makes future chain maintenance easier. To disassemble a Shimano, you need to use the chain tool to drive out a pin, then to reconnect, you need to use the chain tool and drive in a new pin.

You can get a SRAM 8 speed chain: 830 chain for $9 / SRAM 850 for $12 or SRAM 870 for $16. Any will work, and are mechanically equivalent.

I view chains as a maintenance item. I replace roughly every 4,000 miles or so, when the measured stretch approaches 1/8". As others said, and elongated chain essentially reshapes the teeth on the cogs in the cassette, and thus when you install a new chain, it may jump/skip when you apply power. I try to replace before this damage occurs, but I do end up replacing the cassette for every two or three chains.

Good that you measured your chain as preventative maintenance and I hope you cassettes are still good.

fietsbob

worn out chain has worn out wherever it touches, too ,.. so you may have to replace cogs front and rear too,,

cassette & chainrings...

spelger

Thanks all. new chain going on tomorrow. if trouble under power guess a new cassette is in store for me as well.

-scott

davidad

Replace the chain at 1/16" wear. Depending on how you clean the chain the smaller cogs should last through three or four chains.
https://www.sheldonbrown.com/brandt/chain-care.html

andreakane

Wow! I did not know this about chain checker tools. In my past experience, I used one that must've been 3 or 4 inches long, stainless steel with hooks on either end. When I was shown how to use it, it seemed pretty straight forward.

andreakane

For me, personally, I could not always rely on comparison to the old chain since worn chains might have stretch in them and can mislead you to break your chain too long. I have found more reliable success when you size the chain routed along your largest front chainring against your smallest back cog on the rear. Park Tools has awesome, in-depth yet clearly explained videos on YouTube to measure and size your chain. I'm sure your local bike shop won't mind taking a look at whether the teeth to your cassette or front chainrings are worn to see if the problem isn't just the chain.

Iride01 

Many of the popular chain checker tools don't check to the same side of the roller. So they also are measuring the wear between that roller and the bushing whether it's the newer links that have the bushing as part of the side plate which some thinks makes it "bushingless" or the older chains that had actual separate bushings. It's not wear between the roller and bushing that is an issue. It is the wear on the pins and plates that is an issues as it allows the distance between the links to grow and as the cog teeth engage the chain, more wear forces will be greater. Wear between the roller and bushing isn't as wearing on the cog teeth as the roller spacing is still maintained by the spacing of the pins in the side plates.

https://www.bikeradar.com/features/h...bicycle-chain/
https://www.velonews.com/gear/techni...r-measurement/

If you have not already spent money on a chain checker, then the tools that measure to the same side of the bushing will be more accurate. However, even the inaccurate tools are erring on the better side and will have you replacing your chain a little early as opposed to too late. So no harm done except you might have to budget a case or two less beer in your lifetime since chains are more important. <grin>

I still use the "inaccurate" chain checkers. I already had one before this was a known thing to me. They are still quick with the chain on the bike. A ruler will require me to get in a well lit area and position the bike where I can see the scale well. So I don't have to bring out a metal scale till the checkers start to show a problem.

Yes, I can see that happening. You might though know by eye that you need to check more carefully if the links of the new chain aren't fully straight. If not, count them. Breaking it too long isn't really a problem. You can always shorten it. And if you have extra pins, you can lengthen it too. For any bike you don't know the history of, you need to do the chain sizing method that is best for your setup. 1x, 2x, 3x can all have different methods of sizing. I go by the component manufacturers recommendations. And if you want to size the chain every time you change it, that's not any significant amount of time either.

dedhed

You need a 6-7-8 speed chain from any reputable brand (preferably with a quick link), a chain tool, and time.
You'll usually need to shorten a new chain.
Plenty of youtube videos out there.
Remove old chain - quick link or push a pin out with chain tool.
Shorten chain to match old chain length with chain tool.
Install new chain feeding it through rear derailleur correctly and closing with quick link
Ride it and see if anything else is worn enough to not play nicely with the new chain. If it plays well together - Done
If it doesn't, you'll likely need to replace the cassette/freewheel which will require 1 more tool to remove/replace. Chainrings do not wear nearly as fast as rear cogs.

dedhed

Just count links.
Any wear is not going to add enough significant length to add up to breaking the new chain an extra link.

Iride01 

might be on some of those recumbents with 12 feet of chain. <grin>

spelger

So replaced the chain today and used my chain tool that i bought over 20 years ago in preparation for a bike tour in the philippines but never took (got married instead, but that is another story).

holy cow! that was actually hard. i though i was doing something wrong but i finally got one of the pins out. shimano chain. seemed like it took forever, the tool really has no mechanical advantage, i had bought it for its compactness. anyway, chopped of a few links from the new chain, installed, and the ride was like night and day. shifted like as smooth as a baby's...and was the ride ever quiet. i really need to monitor that chain more frequently. even seemed to make me go faster*.

-scott



*absolutely no wind while out riding, average speed was about 3mph greater than usual. no wind is rare for reno.

krecik

sweeks

This ^^. The chain-check tools serve as convenient "screening" tools... easy and fast to get a quick read on chain wear (and without getting fingers greasy). If excessive chain wear is indicated, then a "ruler" check can always be done. Since most chain-check tools seem to slightly over-estimate chain wear, the risk is that a chain with some remaining usable life will be discarded. I'd rather pitch a chain that I *could* get a little more life out of, than wear out my cassette or chainrings.

Thomas15

I agree with this and this is my practice. I buy a few KMC chains at a time, they are about $15 +/- and keep them around and replace when my $4 chain measure tool indicates 75%

jpc2001

My daily driver '80s Miyata has been shifting a little vague so I measured the chain today. I was expecting it to be 1/16" over, maybe a bit more. It's been a few months, it's probably time.

I was not expecting it be 1/4" over on 10" worth of links, and maybe even a hair worse, but that's where it is. Eeeep. I am apparently not good at preventative maintenance. (Yes, I oil it with Tri-flow and wipe it down periodically. No, I don't keep it shining spotless clean, who has time for that?)

Now should I order a new freewheel preemptively, or wait for the chain to come in and try it. Maybe it won't slip...

spelger

does not seem like much harm to just replace the chain and see where the chips fall, then take it from there.