Loose Chains

[Ga Mtn Man]

I've been hesitant to post a question like this because I'd have to admit how little I know about chainsaws, so please be kind to this chainsaw neophyte. 

When the chain gets loose, is the chain stretching or is the bar slipping?  It just doesn't seem possible that the chain could be stretching as much and as often as I have a loose chain.

[terrifictimbersllc]

Chain stretching.  Bar has a hole that a fits over a pin held by a screw, can't slip if it's on right.

[Ga Mtn Man]

How much can a chain stretch?  It seems like I'm constantly having to tighten the thing.  It's an Echo CS-440.  I've always thought that the bar must be slipping so, over the years, I've over-tightened the bar nuts so much that I broke the metal insert in the brake cover.

[John Mc]

Chains will stretch significantly when new. When I put on a brand new chain, I can see the difference after one or two cuts. Once it's been used and readjusted a few times, the stretching slows down a lot.  Cutting with a dull chain will cause it to stretch more and faster.

Another thing to do when installing the chain: before you tighten the bar nuts down, lift up on the bar. Holding the bar up while tightening the bar nuts keep the chain tight. There is not a whole lot of play in the bar. but if you set the tension and tighten the nuts while the bar is in the down position, the chain will be a bit looser as the bar works its way up in use.

[beenthere]

GA Mtn Man
Which chainsaw are you having problems with? And is it one with the "easy" non-tool adj. feature? 

Personally, I find chains do very little "stretching" and any looseness over time amounts to very little adjustment in the bar.

[Ga Mtn Man]

It's an Echo CS-440 with a screwdriver type adjuster at the front of the saw.

[pineywoods]

Chains stretch very little, things wear. Don't overlook the sprocket that drives the chain, it wears, and if it's about gone makes for slack in the chain. If you install a chain that doesn't quite match the worn teeth on the sprocket, the two will quickly wear to a fit, leaving the chain loose...

[Reddog]

I'd have to admit how little I know about chainsaws, so please be kind to this chainsaw neophyte. 

Lets start with the simple things.

When using the tension adjuster don't back off the tension after tightening the bar nuts.
Hold the tip of the bar up while tightening the chain tension and then while tightening the bar nuts, to remove the slack.

Dull chain and the heat it makes cause stretch. Keep a sharp chain.

[John Mc]

For you guys that aren't seeing much chain stretch, what brand are you using? I've heard that Stihl chains are "pre-stretched". I don't use them so can't comment. I can say that the Oregon chains I buy do stretch, though by the time I've run a tank or so of gas, it seems pretty much done stretching.

John

[beenthere]

Stihl chains... and I don't quite understand what could be "stretched" in a chain. Slack from loose tolerances in links and rivets? I can understand some "stretch" from links that get straightened out from their being folded up in the packaging, but nothing where the links could be stretched. 
Slack from wear also understandable, if not oiling or if the chain heats up. 
Keep hearing that chains stretch, but can't wrap my brain around how.

[luvmexfood]

Don't know exactly how to word this to make it say what I am thinking. When you put on a chain, new or one that has been off the saw for awhile, it's not as much as the chain stretches but when being installed you just didn't get the slack out of it good. I find sometimes after installing a chain that it needs a few revs to get this slack out of the chain and then retighten.

To repeat what was stated above make sure the bar is pushed up as you tighten and your drive sprocket is not overly worn. It could have some low spots in it and the chain may be tight when against the sprocket in a certain area but as it travels around it could encounter the low spots allowing it to be less tense.

[sandsawmill14]

The oregon sawchain does stretch on my saws, its actually wearing the pins and holes in the links at least in my case. you can lay the chain down flat and push/pull on 2 links and measure on an old chain then compare to a new one. If you get a measurement of only .005 that is a little over 3/8 inch stretch on a 24" bar/chain. Running a dull chain as already mentioned definitely makes it happen faster. The oregon stretches faster than the stihl chain but i still run mostly oregon because its what the truck that comes to my mill carries

[Andyshine77]

Saw chains really don't stretch, they wear. Most of this is caused buy improper sharpening and warn drive components. Poor lubrication can factor in, but as long as you use proper bar oil you'll be fine.

I cannot stress how important a properly sharpened is, when working with a chainsaw. It save wear and tare on the saw, yourself, improves productivity and safety.

Here is a simple, basic way to file a chain, that will cut really well. 

         

[John Mc]

If you don't think the length of a chain changes over its life, measure one brand new, then one that has been well used and is nearing the end of its life. In fact, compare one that is new to one that has only been used enough to require a couple of sharpenings. Even if it's the same brand an model of chain, you'll see a noticeable difference - and it's not just on "abused" chains or ones that were run dull.  The change is more likely due to parts wearing and rivets "seating" than metal actually "stretching", but the difference is there. From what I've heard, it's less noticeable on Stihl chains, but not having checked one out myself, I can't say for sure.

[Andyshine77]

If you don't think the length of a chain changes over its life, measure one brand new, then one that has been well used and is nearing the end of its life. In fact, compare one that is new to one that has only been used enough to require a couple of sharpenings. Even if it's the same brand an model of chain, you'll see a noticeable difference - and it's not just on "abused" chains or ones that were run dull.  The change is more likely due to parts wearing and rivets "seating" than metal actually "stretching", but the difference is there. From what I've heard, it's less noticeable on Stihl chains, but not having checked one out myself, I can't say for sure.

Correct wear.

I'm talking about chains that are hanging down an inch from the bar after making a few cuts, is caused by dull chain, warn drive components.

[John Mc]

Agreed. If you have a chain that's hanging an inch down from the bar after only a few cuts, either it wasn't adjusted properly to begin with, or something else is wrong.

[Hitchcock Woods]

Chains stretch very little, things wear. Don't overlook the sprocket that drives the chain, it wears, and if it's about gone makes for slack in the chain. If you install a chain that doesn't quite match the worn teeth on the sprocket, the two will quickly wear to a fit, leaving the chain loose...

This is very good advice, Someone else suggested keeping your chain sharp which is also sound advice.  I would make sure the oiler holes on your bar are clear, your oiler is on a high setting, and functioning properly.