Which sprocket is faster 7 or 8 tooth?

[outsideventman]

I have a Stihl 025 and it has a 7 tooth sprocket, I was wondering which one turns faster, the 7 tooth or 8 tooth?

 

[JONSSTIHL]

the 8 tooth will turn the chain faster in the air but in a piece of wood with an 025 it will cut slower I would stick with a 7 tooth

think of it as being in 8th gear instead of 7th gear in your truck you will go faster in 8th gear going down hill but if your truck doesn't have enough power to climb a hill you will go slower in 8th gear uphill than in 7th gear

James

 

[computeruser]

8 tooth - each crankshaft revolution will be pulling 8 drivers through instead of just 7. You will gain chain speed at the expense of torque, like going from a 4.11 rear end (7pin) to a 3.31 rear end (8pin).

An 025 should be running .325 chain and a 7 pin for best overall performance.

EDIT: Like johnstihl said. He's a faster typer.

 

[omegajim]

7 vs 8 tooth

Off the topic, but who carries 7 and 8 tooth sprockets for Stihl? In particular, I have a MS290 (Yes, I know, underpowered, overweight and so on).

Currently it has a 0.325 chain (and sprocket I would imagine) but I was looking for an aftermarket bar. On occassion (very occasionally, like 1 - 2 a year) a larger bar would come in very handy. However, these bars are made for bigger saws, and they are all 3/8. Is there a 3/8 for a MS290? I know it's not a good idea, but it's not likely I'll be buying the 361 or 440 (oh, I wish). So what is around?

No, I don't make a living sawing. Going broke with an underpowered saw wouldn 't cut it (ouch that hurts).

 

[manual]

Sthil makes the sprockets you are asking about.
I used a 029 super for a long time you won't go broke using it.
Yes you can and I would put a 3/8 bar on your saw I used a 18" bar.
search the post for muffler mods and go for it.

 

[computeruser]

Off the topic, but who carries 7 and 8 tooth sprockets for Stihl? In particular, I have a MS290 (Yes, I know, underpowered, overweight and so on).

Stihl and Oregon make 'em, so either hit up your dealer or call Bailey's.

Currently it has a 0.325 chain (and sprocket I would imagine) but I was looking for an aftermarket bar. On occassion (very occasionally, like 1 - 2 a year) a larger bar would come in very handy. However, these bars are made for bigger saws, and they are all 3/8. Is there a 3/8 for a MS290? I know it's not a good idea, but it's not likely I'll be buying the 361 or 440 (oh, I wish). So what is around?

All Stihl saws 024-066 use the same bar mount, so you shouldn't have a problem getting a larger bar for your saw. I'd stick with .325 on that saw, especially with the longer bar, and run skip chain on anything larger than 20". A quick look over at Bailey's shows that even something as big as the 36" Windsor Speed Tip can be ordered with a .325 tip. So it looks like your problem is solved! In the event that you want to buy from your Stihl dealer, they should be able to swap a 3/8 tip for a .325 tip for you at minimal cost.

You can run 3/8 on that saw, and many do, but having owned one in the past I would suggest sticking with the .325. Even with a 20" bar it was easy to get the saw out of its powerband and bog things down. No sense asking the saw to work too hard trying to take larger bites with 3/8 chain.

 

[begleytree]

my 029 super has a rim sprocket 7 pin 3/8 with a 20" bar. with full skip, it is better than it should be, suprising actually. and thats 50 gauge. most 325 around here is 63 gauge. dont see how it can be faster if its cutting an extra 13 thou wide, but thats what guys around here buy.
-Ralph

 

[manual]

I don't know, I'm just not a fan of the 325 chain. Of course I cut fire wood.
and that was when I bought full cords. depending who you buy it from or the time of the year. the wood seemed to be dirty. I seem to always have to file my chain more often then the 3/8 chain. So I like using the 3/8 better.
Now a guy down the road likes the 325 chain and thats all he uses on his husky 346. But he doesn't cut wood in a wood pile.
Watch your raker depth and lighten up when you feel your saw start to bog down. 3/8 works fine. I never used a 8 tooth sprocket eather.
I am trying one out right now on my 2171.

 

[SawTroll]

....
All Stihl saws 024-066 use the same bar mount, .....

Not the 025/250, otherwise right on......:angel:

 

[Freakingstang]

my 029 super has a rim sprocket 7 pin 3/8 with a 20" bar. with full skip, it is better than it should be, suprising actually. and thats 50 gauge. most 325 around here is 63 gauge. dont see how it can be faster if its cutting an extra 13 thou wide, but thats what guys around here buy.
-Ralph

I've never ran 063 chain, but i thought it was just the thickness of the driver and the groove in the bar? I thought the cutters were actually the same between the three chains......

 

[computeruser]

Not the 025/250, otherwise right on......:angel:

Really? Gee, learn something every day.

 

[SawTroll]

I've never ran 063 chain, but i thought it was just the thickness of the driver and the groove in the bar? I thought the cutters were actually the same between the three chains......

I believe that you are right, regarding Stihl and Oregon chain, but believed otherwise earlier.

There was a lenghthy disscussion of this issue some time ago.

I'm still not 100% sure.........

 

[SawTroll]

Really? Gee, learn something every day.

MS250 use the same one as the smaller Stihls.

 

[calpyro]

I use a 8 tooth sprocket on our 046 Magnum's at work. We run a carbide chain for rescue and firefighting. The saws will cut roofs and maintain 12000+ RPM under load. This provides the equivalent chain speed of the saw with a 7 tooth sprocket at 13700 RPM.
In some applications, a larger sprocket will provide better performance, but it requires some testing to be sure.

 

[Justsaws]

20" bar and 7 tooth sprocket .325 is about as much as any of my 290s liked to do. I cut almost exclusively down and or dead wood and an old hard 18" locust would work the saw good. I tried 3/8 and it was not for me on that saw. The 390 is they same way, which is why very shortly I will no longer have any of them. I ordered my rim system from Bailey's and they have plenty of bars to chose from as well. Good luck.

 

[outsideventman]

I use a 8 tooth sprocket on our 046 Magnum's at work. We run a carbide chain for rescue and firefighting. The saws will cut roofs and maintain 12000+ RPM under load. This provides the equivalent chain speed of the saw with a 7 tooth sprocket at 13700 RPM.
In some applications, a larger sprocket will provide better performance, but it requires some testing to be sure.

We use the Cutters Edge which is a souped up Jonsered as you probably know. Are you interested in trading dept. patches? Let me know.