If 3/8 takes more power

[kellysguy]

then why do manufactures use it on small saws? I noticed Echo uses 3/8 on everything. If it takes more power to run a 3/8 chain then why use it on a 30cc saw? Is it a production cost thing?

[so il logger]

I wasn't aware echo uses 3/8 on everything. Pretty sure they don't, as I have had one that was .325 Put a .404 on a 70cc saw and you will understand  More pull via chain weight and more tooth contact will rob power out of a already smallish saw.

[starmac]

From what I understand, what is used is a 3/8 low profile, whole different animal from regular 3/8. I could be all wrong though.

[LeeB]

Echo's website offers 3/8 and .325 chains. I don't see any other sizes listed.

[ladylake]

Echo uses 3/8 low pro on their saws up to 40 cc and they really cut , the big difference is they use a 6 tooth driver.  I tried a 7 tooth which cut quite a bit slower than the 6 tooth.. The 45 to 50 cc saws will have a .325 7 tooth and the 60 and above will have regular  3/8 with a 7 tooth driver.  Steve

[kellysguy]

There was a major suppliers site that showed the "recommended" chain for all echo models from 310-590 as 3/8 which is where the statement comes from. I want to say it may have been a box store but I could be wrong.

So then I take it that 3/8 LP has less drag than .325, is that correct?

[SawTroll]

Drive sprocket size is a major factor here, but the end result also depends on exactly which chain models are involved

[kellysguy]

Drive sprocket size is a major factor here, but the end result also depends on exactly which chain models are involved

I understand that completely, with all things being equal are the 3/8LP the easiest to pull? (excluding 1/4 of course).

[Philbert]

'3/8' is the pitch - the average distance between the rivets in the links.  It does not determine the height, width, shape, or size of 'bite' of the tooth.  As noted, 3/8 low profile is really a different animal than full sized 3/8 chain, as they don't even use the same sprockets.

In terms of power required to pull a chain, I think of this sequence (low power required to high power required):

1/4", 3/8 low profile AND narrow kerf (e.g. Oregon type 90), 3/8 low profile (e.g. Oregon type 91), .325 narrow kerf (e.g. Oregon type 95), .325", 3/8", .404".

Of course, there can also be some differences between manufacturers of the same size chain; if the chain is full-chisel vs. semi-chisel, how it is sharpened, etc.  Saw manufacturers will also use skip tooth, and semi-skip tooth spacing to sometimes put larger pitch chain, or longer bars, on lower powered saws.  This is somewhat deceptive in my opinion, but legal.

Philbert

[HolmenTree]

3/8 LoProfile chain or Picco as Stihls trademark is actually  an extended pitch 1/4" chain made into 3/8" pitch. Oregon introduced  it as a manufacturing cost saving consumer  chain  in 1975. Stihl Picco in 1979.
Less pieces per foot was the savings.
Before 1976 the 1/4" chain was outfitted on all small cube saws as the preferred  chain . But many more pieces per foot make it an expensive  chain to manufacture as todays prices of 1/4" chain proves.
This chain cuts a narrower kerf over the larger chains and has a smaller bite with it taking a 5/32" file.
As said a 6 tooth spur drive  sprocket  as a " lower gear" helps the little saw powerwise too .

[kellysguy]

Thanks guys, I really appreciate it. I finally got them both together and can see the difference now. Man that LP is small. I'm surprised how well it cuts but it makes sense on such a small saw.

[HolmenTree]

Now I'll  make things really confusing 
Here's  another low profile 3/8" chain......the Oregon 76LG. Introduced in 1976 and discontined about 20 years later.
An actual true 3/8 pitch chassis to match a full size 3/8 sprocket.
Cutter bits are equivalent  in size to a .325 and chisel to boot.

Top picture....76LG
Middle picture ...old timbersport race chain trick. Full size cutter on lightweight  76LG chassis.
Bottom picture.....Stihl 33Topic Super 3/8" low profile chain compared to full size Stihl 33Rapid Super 3/8"chain.

 

  

  

 

[kellysguy]

 

[pabst79]

X2   

[SawTroll]

Drive sprocket size is a major factor here, but the end result also depends on exactly which chain models are involved

I understand that completely, with all things being equal are the 3/8LP the easiest to pull? (excluding 1/4 of course).

I believe at least most 3/8" lo-pro chain "pulls" easier than 1/4" chain, as there are way fewer cutters?

However, I am not an expert on 3/8" lo'pro, as I haven't used it for 15 years or so, and I never used 1/4".....

[Cut4fun]

Now I'll  make things really confusing 
Here's  another low profile 3/8" chain......the Oregon 76LG. Introduced in 1976 and discontined about 20 years later.
An actual true 3/8 pitch chassis to match a full size 3/8 sprocket.
Cutter bits are equivalent  in size to a .325 and chisel to boot.

Top picture....76LG
Middle picture ...old timbersport race chain trick. Full size cutter on lightweight  76LG chassis.
Bottom picture.....Stihl 33Topic Super 3/8" low profile chain compared to full size Stihl 33Rapid Super 3/8"chain.

 

I understood 100% of all of that. 

[Philbert]

I understood 100% of all of that.

Yeah. Some companies used to make full sized 3/8 pitch chain with smaller cutters. 

Philbert

[HolmenTree]

Thanks to  Kevin (Cut4fun) a few years ago I was able to buy about 9 loops of the 76LG and 33TS chain from him that he found.
I haven't  been able to find this chain for about 20 years  prior.

[SawTroll]

Now I'll  make things really confusing 
Here's  another low profile 3/8" chain......the Oregon 76LG. Introduced in 1976 and discontined about 20 years later.
An actual true 3/8 pitch chassis to match a full size 3/8 sprocket.
Cutter bits are equivalent  in size to a .325 and chisel to boot.

Top picture....76LG
Middle picture ...old timbersport race chain trick. Full size cutter on lightweight  76LG chassis.
Bottom picture.....Stihl 33Topic Super 3/8" low profile chain compared to full size Stihl 33Rapid Super 3/8"chain.

 

 (Image hidden from quote, click to view.) 

 (Image hidden from quote, click to view.) 

 (Image hidden from quote, click to view.)

Basically true, but there are no such thing as true 3/8" chain, as the pitch basically are .366 on both regular and lo-pro, and not .375. 

[HolmenTree]

Basically true, but there are no such thing as true 3/8" chain, as the pitch basically are .366 on both regular and lo-pro, and not .375. 

You know what I mean Niko
I was just saying the 3/8 low profile 76LG and 33TS are true 3/8 chassis to fit a standard sprocket where the 91 series or Picco 3/8 LoPro chain are not a correct fit.
The guide bar companies who have spent millions of dollars in research and development for the last 60 years or so still call the 3/8" pitch .375 as the numbers on my bar tip shows..............