Lo Pro .370 pitch and .375 sprockets

[Crofter]

Why the discrepancy. I dont see any 370 sprockets listed. I am going to hazard a guess here and certainly stand to be corrected. I am thinking that since the tie strap is shallower from bottom to centre of rivet line, that the effective pitch line of the chain is enough closer to centre of sprocket that a .005 thou less pitch effectively gives the same working relationship with the sprocket as on a .375 standard profile chain. They both work properly with a .375 sprocked.

Frank

 

[HUSKYMAN]

?
I have never been able to run low pro chain on 3/8 stuff. Thats why I had to get a new sprocket for my Poulan 25.

 

[Crofter]

Huskyman:

Why couldnt you run it and what was the difference in the two sprockets. How about the nose sprocket. Are we talking about extended pitch Lo Pro chain with a nominal .370 versus 3/8 standard chain of both the same guage?

Frank

 

[Stumper]

Huskyman-maybe you were running .325. I think the .370 designation is simply a short way to designate 3/8's Low Profile. I can't measure any difference between it's pitch and 3/8's(.375). Even if it is 5 one thousandth's of an inch shorter in pitch How can it possibly matter-when you run your new chain and it stretchs a half inch the first hour how many thousnths did the pitch change? How about that 3/4 used up chain that you actually have to remove a drive link from in order to be able to tension it properly? Five thousandths is tiny-the system allows for more slop than that without problems. 50 thousandth's is another matter.