Oregon Lo Pro chain

[alderman]

I e-mailed Oregon chain to see there answer on the 91 Lo Pro chain pitch. They said it is a true .375. Anybody have any ideas on why it wouldn't work on a regular .375 sprocket?

 

[SawTroll]

I e-mailed Oregon chain to see there answer on the 91 Lo Pro chain pitch. They said it is a true .375. Anybody have any ideas on why it wouldn't work on a regular .375 sprocket?

The sprocket needs to be larger, because the chassis of the chain is lower. Pitch is measured at the rivets, not at the bottom of the chain.

There are no .375 pitch chain - the real pitch is about .367 for all 3/8" chain, lo pro or regular.

 

[mtngun]

What Sawtroll said.

Some people do run lo-pro on 3/8 sprockets and get away with it, but when I tried it, I ran into problems.

Read the whole thread, because there's some misinformation early in the thread that is corrected later on.
http://www.arboristsite.com/milling-saw-mills/121746.htm

 

[alderman]

Well my setup would include an Oregon 91 bar which I assume has a nose sprocket for lo-pro.

The mesh on the drive sprocket would be the only issue as far as I can see. I could be wrong, but somebody here feel free to critique this thinking. The way I read this is the only harm can be to the chain drive links and perhaps the drive sprocket and may take some running to determine this.

Also something that may be a factor with this is I'm only running this on short 14-16" bars and HP under 3.

The only reason I got into this is several of the smaller saws I've boughten have come to me with this set up.

 

[Sagetown]

The low profile chains are not to be confused with its larger kin the standard chain.
Here are the differences.
The 3/8" low profile, or in the STIHL version (picco), is smaller and has a shallower drive link than does the heavy duty standard (STIHL= rapid) 3/8" chain.

THUS; the standard chain will stand up above the Guide Bar due to the larger and taller drive links.

The ‘PITCH’ in this case is 3/8" in both the low-profile and standard chains. What this means is that the distance between the same pin holes of two drive links (Or three rivets divided by 2) in the chain is 3/8" or .375".

 

[Sagetown]

Sorry; I had to read all the posts over a few times to understand what you're after.
Seems you want to run a low profile chain, using a low profile chainbar on a saw that uses a standard 3/8" Drive Sprocket. I've never seen a setup like that, so I have no clue as to whether that will work or not.

 

[alderman]

Thanks for the info on this. I would imagine as I was told earlier that it's not worth the hassle.

Will probably run .325 and avoid the headache. I've run .325 on saws up to the 488 and it cuts fine.

 

[SawTroll]

Well my setup would include an Oregon 91 bar which I assume has a nose sprocket for lo-pro.

The mesh on the drive sprocket would be the only issue as far as I can see. I could be wrong, but somebody here feel free to critique this thinking. The way I read this is the only harm can be to the chain drive links and perhaps the drive sprocket and may take some running to determine this. .......

Right, and mayby problems with getting the chain tension right, and maybe a larger chance for derailings etc.

 

[alderman]

Right, and mayby problems with getting the chain tension right, and maybe a larger chance for derailings etc.

SawTroll: Thanks for steering me straight on this one. I needed the info to understand the issues. I appreciate you jumping in as the kind of knowledge you pass on usually isn't free.

 

[alderman]

I checked out my 377 today and found out the dealer had put a regular 3/8 drive sprocket on it when I got it. It had a lo pro bar so that was right for the bar sprocket. I switched thing over to .325 sprocket and bar as the sprocket was already showing some wear even with the little bit I have used it.


All the rest of my saws with lo pro setup have the right spur sprocket on them so will run them that way until they need new sprockets.