Confused? 72 vs 70 drive link

[jughead500]

Sorry for the stupid question... I just never paid attention... And I'm new to this..My family has sold saws since they where invented and my uncle is a saw expert..so is it the bar sprocket or the drive sprocket that's different on a 72/70

neither.its the actual bar length.

 

[HarleyT]

Yeah, different mfgrs. measure 20 inches differently....

 

[SawTroll]

Sorry for the stupid question... I just never paid attention... And I'm new to this..My family has sold saws since they where invented and my uncle is a saw expert..so is it the bar sprocket or the drive sprocket that's different on a 72/70

"Called" bar length isn't accurate at all, some bars are much shorter than called, and a few are longer. Most are a little shorter than called though.

Regarding the dl count, a wider nose usually is compensated (by a shorter bar) to make the same dl count by the factory, but a large drive sprocket some times throws the dl count off, so you need an extra dl in the chain (often the case with 9-pin vs. 7-pin, but mostly not with 8-pin).

 

[Philbert]

. . .so is it the bar sprocket or the drive sprocket that's different on a 72/70

neither.its the actual bar length.

Or the shape of the bar - different circumference.

Philbert

 

[jughead500]

Yeah, different mfgrs. measure 20 inches differently....

believe some

Or the shape of the bar - different circumference.

Philbert

zactly

 

[Wasted_Potential]

Or the shape of the bar - different circumference.

Philbert

I created an account just to resurrect this threat to point out the fact that it took 4 pages to finally give the answer.

I was wondering the same as the OP. After reading two pages of "what are you asking" it finally clicked in my brain that a 20" long oval has a different circumference if its a bit more oblong, so a slightly wider bar would require a slightly longer chain, even if it's the same length as a narrower bar.

 

[Maintenance supervisor]

Tail of the bar in relation to the sprocket, determine the dl also.

 

[TRTermite]

ECHO 590 Timberwolf Came in scored. Owner was trying to save some money. Used a bar he had from a Jonsered 2159. Oiler hole was at the top Edge where chain rides the rail. drive link numbers were worn off from lack of oil. pump froze .. A Stihl 3003 mount fits the Echo 590 oil configuration perfect, Echo studs needs bushed (Adapted) to fit the wider Stihl slot. The Stihl bar is a "TAD" longer -72DL verse the flimsy (Customers words) Echo Bar -70 DL (3/8" chain) Oregon FOR Stihl 3003 is 72DL also.