Chain length question
 

Hi- I'm new so please forgive my silly question. I have an older, 12 speed (I think you all now call it a 6 speed-6 cogs), with all Shimano 600 components. I purchased a new chain today, leaving the selection up to the sales person. When home, the new chain is about 3 inches longer. The old chain has, I believe, 110 links and the new one has 116 links.
Is it the right chain and the old one was incorrect, or what? Thanks so much!

New chains are cut to fit

Run the new chain around the big chainring, and the big cog, and add 2 links. Then cut to fit. This requires the use of a chain breaker tool.

It's the right one; you need a tool called a chain breaker to eliminate three extra links (and join the chain ends if you do not have a reusable link).

I suggest having the shop install the chain; if they let you watch you will learn how it works.

Thanks so much! The new chain has a reusable link. I don't have the tool but I think I'll try a nail set to remove the links. Thanks again

a nail set to remove the links?! that is just one step from just cutting the excess chain off with a hacksaw. go out and get a chain breaker. please. park tools makes one that will probably out live you, but any cheaper one will do the trick. or take the chain to the LBS and have them adjust the length for you, so all you have to do is install and slap on the master link.

i hope a nail set isn't what i think it is. get the tool. they are easy to use.

Yeah, I know. But I live 30 miles from the nearest LBS, or any other store that may have the tool. And I'm not known for patience and want it done tonight! lol
The nail set worked-it's like a small punch. I used it to remove the pin (with a small hammer) holding the extra links and placed the "Missing Link" in position. To set it properly, it says to crank the chain and the link will seat itself. We shall see! If worse comes to worse, I'll just make the 60 mile round trip tomorrow. Thanks!

add one link (that's two half links). just to avoid confusion. also, invest in a masterlink. you'll be happy next time you want to clean your chain.

Well, he's already said he doesn't have a chain tool (so much for adding a link; and why would he want to do this?) and he also said he has a reusable link (aka master link).

Do you actually read these things before posting? ;)

you want to add a link so that the chain isn't too long (a too long chain will cause two things: sloppy shifting and drag on the rr der cage in the L-A gear combo) and as far as my missing he already owns a masterlink, there was a long gap of time from when i composed my reply to when i hit the "post" button (my wife walked into the room...:love:)

"If all you have is a hammer, everything looks like a nail"

and you add a link after running the chain in the H-Z gear combo (ie: large front chainring and large rear cog) find the link where the chain meets, and then add one link (or half a link if using a masterlink)
L-A gear combo = small front chainring and small rear cog

The method of adjusting chain length that is totally foolproof requires the chain to be on the small ring and smallest cog, routed through the RD as you normally would. When the ends of the chain are brought together, the RD cage will swing forward slightly, giving the maximum length that does not allow the chain to rub on the upper pulley guide tab or hang loose. You then get the maximum length that should work with any cassette within the RD's wrap capacity. This method work with any double or triple drivetrain and you won't make any mistakes by adding or subtracting the wrong number of links.

For a road bike, one chain length will work with any cassette from an 11-21 to an 12-27.

bull!

Now, now! I had no intention of creating such discord, lol. At any rate, I installed the chain and it works perfectly. To celebrate, I went ahead and drove from these woods to town and bought the chain tool, and new 105 shifters (down tube), and an Ultegra front derailleur-what a mutt bike! Now, I'm happy. For the moment. Thanks again to everyone who , at least, tried to help me.

+1. That method can give too short a chain to cover big-big unless you are within the wrap capacity of the rear derailleur and, even then it's uncertain.

The proper way is to follow Sheldon Brown's procedure of wrapping over the biggest chainring and the biggest cog without going through the rear derailleur. Add two half-links (1") and cut the chain at that point. That guarantees the chain is the shortest that will allow big-big, which is a mechanical necessity.

If you are within the rear derailleur's capacity, it will allow small-small also. If not, small-small will leave the chain too slack which is not damaging.

A good discussion is better than just posting Bull, but if it make you feel good...

Those who read my post about using the little/little combo didn't read close enough to note that it works for any setup within the the RD's wrap capacity. To quote from this post:

"You then get the maximum length that should work with any cassette within the RD's wrap capacity."

That is NOT uncertain.

It's never wise to exceed the wrap capacity of the RD. If you do, then you have to pick whether you think you can avoid the big/big combo with the chain at it's normal length or add an extra inch of chain and avoid the small ring and several of the smallest cogs. 1 inch of chain is equivalent to 4T of wrap.

Exceeding the RD's wrap capacity isn't done very often, except by those using 9 speed MTB cassettes with a short cage road RD. I've exceeded the RD wrap capacity using a 28T little ring on a road triple, but the smallest several cogs shouldn't be used with the little ring, so it wasn't an issue.

The big/big method is OK for those who don't change cassettes often, but if you were to switch from an 11-21 or 11-23 to a 12-27, you'd find the chain too short. With my method, you'd have a 1-inch longer chain and no problem with any standard road cassette.

Yeah, but the OP counted the links on his old (and presumably fully functional, just worn) chain so why worry about it?

Those links are a standard size, you know; 110 is what he (still) needs.

Counting links is a waste of time. Use the proper method to set the length once. When it comes times to install a new chain, remove the old one, lay it out on a bench, with the new one beside it. If the ends are matched up, you can easily get the same number of links, although the old one may be up to 1/4 inch longer than the new one or even 1/2 inch longer if the chain was used far too long.

You can also measure the entire chain length and record for future use. 110 links for example, is 55 inches of chain.

IF you ALWAYS stay with in the rd's chain wrap capacity you are technically correct. To me the uncertain part was how much slack you pull out of the rd when measuring the chain in small-small. If you pull a bit too much, the chain can end up too short for big-big.

Sacrificing small-small or small-2nd small cog isn't giving up anything useful and the inadvertant shift into it doesn't cause any harm.

I routinely exceed the wrap of road long cage rear derailleurs by swapping a 26T granny ring for the stock 30T on road triple cranks used with a 12x27 or 13x29 road cassettes. Avoiding the small- small is a no-brainer.

Yeah, it doesn't make sense to spend all of what, two or three whole minutes to determine the exact length you need when there are so many vastly better (and much faster!) methods that work almost as well! :rolleyes:

If you bring the ends of the chain together and watch the point where the RD cage starts to move, you'd have to be quite careless to accidentally pull an additional inch of chain beyond the minimum. If in doubt, break the chain with the additional inch left on, then bring the ends together again. If the chain has no tension on it, then it's 1 inch too long.

I think we agree that triples exceeding the RD's wrap capacity work fine as long as it's only the smallest few cogs that produce no tension. They should never be used with the little ring.

Another point that is rarely mentioned is that the chainstay length affects wrap capacity. There is 1/4 inch range of chain stay length will give some frames up to 2T more wrap than some others. That's why two bikes with the exact same setup can produce different amounts of chain tension.

Boring.

Big/Big +1 never fails.

Because it's the only chain sizing method which takes into account step 1 the only catastrophic consequence of too short a chain - derailleur explosion. A waste of forum space to even discuss something as simple as 1 + 1 = 2.

You make it sound like this is some oft known fact. Maybe you should frequent the SS/Fixed forum.

You mean, your incorrect hack method right. If you're going to start accounting for throwing on bigger cassettes, why not just start randomly adding extra links to the big/big + 1 method? It does the exact same thing your method does anyways, with the exception of actually being a safe procedure.

Not totally foolproof. This technique works most of the time, but on modern mountain bikes, with really wide ranges (triple on the front, 11-34 on the back) You sometimes end up with a chain that's too short.

Operator. Why not drop the personal attacks and discuss the topic in a reasonable manner? That's too much hositility for a simple subject.

The method that I describe is exactly what is recommned in Campagnolo's chain installation instructions, so it's not a hack method that I cooked up. It's a method the produces one chain length that will handle any cassette within a RD's wrap capacity.

While the big/big method works, it recommends a chain length that is 1 inch shorter than necessary if the cassette has a 21 or 23T largest cog. A later change to a cassette with a 27T largest cog will result in a chain that's too short. My method would handle either one with the same chain length.

If you're deliberately exceeding the RD wrap capacity, then the user needs to decide how they want the drivetrain to work. Some people put a 13-29 cassette on a Campy short cage RD for an occasional hard climbing route, without lengthening the chain, since they feel confident that they will never shift to the big/big combo. With the optimum chainstay length, some bikes can even shift to big/big without problem, but not all of them.

I can't argue with that, not working on MTB's, but it would seem odd for an MTB to have a slack chain in the little/little combo. That would suggest that the wrap capacity of the RD is inadequate. I've set up plenty of road triples and that's the only excuse for a slack chain - inadequate wrap capacity.
A typical MTB RD should have 43T of wrap to handle a 42/32/22 with an 11-34.



http://bike.shimano.com/publish/cont..._mountain.html

Just for the record,My touring bike has a Deore SGS?(long cage) and is rated at 45 tooth wrap.My gearing is 46/20---11/34 and can handle a 49 tooth wrap with no dragging in sm/sm combo.