Stihl Bar Question

[MustangMike]

Nomad Archer is correct, BTW, nice Deer. Go to the Stihl website, under Chainsaw - Saw Chain - Rapid Duro 3. When you click on that you will see a clear picture of what Nomad Archer is talking about.

Also, I run yellow chain on a green bar all the time and have not noticed that. I think SawTroll was correct, the low kickback bar has a smaller nose, so it will reduce kickback with any chain (although more with green chain, of course). Personally, I think the major cause for increased kick back is a dull chain.

IMO, keep your chain sharp and a firm grip on your saw and you will be just fine. If I thought the yellow bar would cut any faster than the green bar, I would use them.

 

[nomad_archer]

Here is the pictures. I did the best i could but the garage is 6 degrees and the florescent lights didnt warm up. Both are semi chisel.

Green safety chain. You can see the bumper and raker.

Yellow chain there is only the raker

 

[treesmith]

I guess the information is only as good as the dealer telling it!

Sent from my GT-I9100

 

[nomad_archer]

A quality dealer makes all the difference in the world.

 

[KenJax Tree]

Quality dealers are hard to come by.


Sent from my Autotune Carb

 

[nomad_archer]

Quality dealers are hard to come by.


Sent from my Autotune Carb

This place helps a lot. I wouldn't know the difference between a yellow or green chain if i didnt come here and find a new good local dealer

 

[treesmith]

Had a fantastic one in Sussex, ATS machinery, developed a relationship when I lived there and they'd send me things wherever I was in the country and even years later. You'd get 20% off machines as standard and they were helpful, knowledgeable and they cared. The closest one to me in Oz now give you a very strange look when you ask for their best price and they are really expensive to begin with. Not impressed at all

Sent from my GT-I9100

 

[MustangMike]

Nice try with the pictures, but he will see it much more clearly if he goes to the Stihl website.

 

[Philbert]

I think SawTroll was correct, the low kickback bar has a smaller nose, so it will reduce kickback with any chain . . .

I think the green bar is slightly fatter in the middle (instead of two flat surfaces), is that correct?

Kickback occurs when the chain hits something in the upper quadrant of the bar nose. The opposite reaction to the chain moving Forward and Down is to propel the guide bar Backwards and Up at chain speeds.



By making the nose radius smaller, the 'target area' susceptible to kickback is reduced.

Since you reduce the size of the bar's nose, you need to compensate in the shape of the bar so that they both use the same number of drive links in a chain loop. This may be why one bar appears to have a 'fatter' belly than another. Or it may be the transition to the smaller radius nose.

But no bars actually have flat surfaces, as I understand it: centrifugal force 'throws' the chain outward, and it would tend to lift out of the bar groove if the edges were actually flat and parallel. The curve is less noticeable on some bars.

Philbert

 

[MustangMike]

Thank you for that, excellent. I will also add that if your chain were sharp it may just go through that wood, but when it is dull it will really kick back! It is just common sense.

 

[Philbert]

Did you see the video in this thread?:

http://www.arboristsite.com/community/threads/kickback-a-mere-inches-away-from-jugular.250630/

Philbert

 

[MustangMike]

Very good video, and it proves my point. Trying to cut a metal fence is even worse than using a dull chain. Boy, that happened fast. I guess that is why all the good saws have chain breaks.

 

[nomad_archer]

Nice try with the pictures, but he will see it much more clearly if he goes to the Stihl website.

Actually the pictures showed exactly what I was trying to show the best I could.

Here are the links I believe you were referring to:

Green Saftey Chain:
http://www.stihlusa.com/products/chain-saws/saw-chains/pm3/

Yellow Chain:
http://www.stihlusa.com/products/chain-saws/saw-chains/rd/