Premature bar wear mystery on new MS 661 C-M

[Trdoldtreecutter]

I put my chains on snug when they’re cold and they do loosen after running but they will have a sag on a longer bar when they cool off. Just the way it is

 

[Trdoldtreecutter]

Not as noticeable on short bars but it is happening

 

[BangBang77]

No, that's not "just the way it is".

You're not high enough on the food chain to redefine the Laws of Physics to adhere to your incorrect assumption.

 

[singinwoodwackr]

I put my chains on snug when they’re cold and they do loosen after running but they will have a sag on a longer bar when they cool off. Just the way it is

supposed to have a little sag with long bars...I usually keep about 1/8" of droop on 36 and up.

 

[Short timer]

supposed to have a little sag with long bars...I usually keep about 1/8" of droop on 36 and up.

The op’s is a 25 inch bar to not get “derailed” too much.

 

[Westboastfaller]

Explain your gibberish please.

I just stated a fact from over 30,000 handle bar hours
People have in mind that metal expands when hot so they make statements over the internet that one should loosen the chain when shutting down or the chain will contract and bend a crank. So that catches on and some mechanic gets a saw with a bent crank and says that over YouTube or saw sites as possibly the cause. I have read that on this site and I read it on an old thread on another site from 10 yrs ago.
Funny, all the Fallers I've worked with or been in camp with probably have 50,000 years experience combined. Never any talk of that nonsense.
"There's those that teach and those that do"
It may be the bar expanding when hot. The chain is oiled and moving so perhaps it cools better. Not to say it doesn't get hot and tight I said "when things cool it gets loose"
If it's tight then it's just going to generate more heat and keep getting tighter where as I would have to stop and loosen it.
More internet bs.

 

[Trdoldtreecutter]

Lol, well, I’m sure there’s some scientific explanation for it. Never thought much of it one way or another. I will say Longer chains will stretch, sometimes to where you have to pull a driver. Especially on new chains. Hate running new chains

 

[Trdoldtreecutter]

I’ve got a lot of miles behind chainsaws and I have never witnessed this

 

[CentaurG2]

Replace your rim sprocket. Only $18 shekels from the stihler. If that does not solve the problem, buy a husky 395xp and you will never look back

 

[BradSt]

Straight out of a Stihl Owner's Manual:
"Always release tension on the chain after finishing work. The chain contracts as it cools down. If it is not slackened, it can damage the drive shaft and bearings."

 

[RED-85-Z51]

Thermal expansion is a reality, metal will expand by Surface area, volume and length when heated.

Sent from my LM-G820 using Tapatalk

 

[Trdoldtreecutter]

I just stated a fact from over 30,000 handle bar hours
People have in mind that metal expands when hot so they make statements over the internet that one should loosen the chain when shutting down or the chain will contract and bend a crank. So that catches on and some mechanic gets a saw with a bent crank and says that over YouTube or saw sites as possibly the cause. I have read that on this site and

Straight out of a Stihl Owner's Manual:
"Always release tension on the chain after finishing work. The chain contracts as it cools down. If it is not slackened, it can damage the drive shaft and bearings."
If that’s what it says, it must be true. Weird I’ve never seen a chain get tight when it cools down. Weirder yet that there would even be a fuss about it. I never seen any of those guys that wrote that out in the woods seeing for themselves if it was true either. This whole thing probably has anyone who has a few years under they’re belt chuckling. As for the original guy posting, I wonder if where he has the wear in the bar he might have gotten pinched. I’ve seen that many times and it will definitely make a hot spot .

 

[Westboastfaller]

Straight out of a Stihl Owner's Manual:
"Always release tension on the chain after finishing work. The chain contracts as it cools down. If it is not slackened, it can damage the drive shaft and bearings."

I'm not shooting the messenger but that's the biggest crook of **** I have ever heard about saws in my life. I have seen some of their testing they do. It's a joke. Most all saws I have to improve things that fail in hard environments.
It's not the reality of what happens when the gear cools off. You almost always have to tighten your chain in the morning or even when you stop for under 10 min or you get chain throws within minutes after starting back up. It only takes minutes for it to cool off. This way of thinking then why are they not telling you to loosen it every time you stop for 10 min then?...haha. Little bars are more forgiving on that with throws.
I've worked in -43 C and likely colder at night and leave my saw out. I have thrown them in the back of truck at -40 (without wind factor from driving) after work. I did 12 winter of that **** in Northern British Columbia & Alberta.
Mostly the chain stretches most when heat is not generated like cutting brush and especially when it's cold and you are digging it in snow.

 

[Jhenderson]

You really should get a big $$$ job with stihl . You know more than all their engineers combined. Seeing as you can countermand physics by getting steel to stretch when cooled there’s no telling what feats of manufacturing wizardry you could use to upend all known facets of their empire.

 

[Westboastfaller]

You really should get a big $$$ job with stihl . You know more than all their engineers combined. Seeing as you can countermand physics by getting steel to stretch when cooled there’s no telling what feats of manufacturing wizardry you could use to upend all known facets of their empire.

If you read my earlier post (a few back) you would have read I offered a possible explanation as to why the chain tighters and loosens when it gets hot then cool. Possibly it's due to the bar expanding & contracting at a greater rate. What do you Einstein's got?
Or you saying a chain won't loosen within minutes after shutting down? And you are saying a previous stretched chain that gets hot alone with the bar can not get tight around the bar?
@BangBang
With your way of thinking then you wouldn't have to tighten a chain. It would tighter it's self within minutes. as it cools.
Theory doesn't always work in practice, pal, as to the way one my think.. I can assure you a have put it to practice since 89'
You guys and the manufacturers can stuff the chalkboard ****. If you don't know this **** then you guys no little about running a saw

 

[Trdoldtreecutter]

Man, I’m really curious what you guys that don’t see a chain go slack after cooling down do for a living. It doesn’t even make it into a discussion in any full time sawing environment. It just is. Why they would say the opposite is true is beyond me but I’ve never heard or seen it be anything but what I have witnessed. So believe what you read but run the sh*t out of a saw, lots of oil, little oil, sharp chain, dull chain. The dam chain is going to have some slack when it cools. If you say anything different than I don’t believe you have any real experience. Good grief lol

 

[singinwoodwackr]

You guys do know that different brands of chains stretch more than others, right?

 

[Westboastfaller]

You guys do know that different brands of chains stretch more than others, right?

Of course, but that's not what the discussion is about.

Say a stihl chain that's not going to stretch much (prestreached I have heard? Idk) Its keeping proper tension whilst Falling,bucking & brushing. So it's not stretching in steady use. Maybe you haven't had a chain throw in 2 days but if you fail to tighter it after your lunch then it will have become loose and guaranteed it will fly off on me under 10 min.
I always have to retighten the chain when I file the next morning or at the end of my break

 

[BangBang77]

Hmmm. I wasn't aware that the Laws of Physics were a theory.

The Dunning Kreuger Effect is in full force tonight.

 

[singinwoodwackr]

Of course, but that's not what the discussion is about.

Say a stihl chain that's not going to stretch much (prestreached I have heard? Idk) Its keeping proper tension whilst Falling,bucking & brushing. So it's not stretching in steady use. Maybe you haven't had a chain throw in 2 days but if you fail to tighter it after your lunch then it will have become loose and guaranteed it will fly off on me under 10 min.
I always have to retighten the chain when I file the next morning or at the end of my break

trudat