Sprocket information required

[stevieb]

Can anyone explain why on a Stihl Picco chain there are different sprockets to choose from for the same pitch chain. example 6 tooth and 7 tooth. Does this make the chain run faster? Thanks

 

[dave k]

Yes a 8 tooth sprocket is faster than 6-7 tooth, for example a standard 660 comes with a 7 tooth sprocket and 3/8 chain I find a 8 tooth with .404 chain far better but thats just my preferance on that saw.

 

[stevieb]

So if I have options of 6 to 8 tooth on a sprocket all options for that saw the more teeth the faster the chain performs? Whats the down side?

 

[zr900]

Loss of torque. Saw will like to bog easier.

 

[stevieb]

Ok now starting to understand like gears on a car. Lower the gear more torque. So It prob depends on what you cutting or how thick your cutting. For example I suppose 6" dia firewood would be suited to a higher speed?

 

[Nailgunner]

^^ that's the score. larger saws will run sprockets with more teeth. The engines run at similar speeds, in the order of 10,000 RPM or so, and the larger ones develop much more torque. So, they can pull the same chain faster without going all weedy and bogging down in the cut. To do this they use more teeth on the sprocket, giving a higher linear chain speed for the same rotational crankshaft speed.

 

[stevieb]

Thanks for the advice. Now becomes all clear.