Drive Sprockets - When Do You Replace?

[lxskllr]

My cs400 has two grooves worn into the spur sprocket, and both are about .5mm deep which is when all the documentation says to change them out. Do you all follow that pretty closely, or do you push it longer? Been sitting on a couple amazon pages with a sprocket and bearing on them, and haven't pushed the button yet. I probably will soon, but I want to get the items on the order I never remember til I submit. I'm thinking I'll run one more chain before changing out, barring poor behavior one way or another.


Bonus question I doubt anyone can answer... Why are spur sprockets still a thing? Rim sprockets are superior in about every way, no? They don't seem to add more cost in manufacturing, so why not use them on every saw? The only benefit I can see with a spur, is it enforces a clutch drum change. Might be better for some end users, but I don't know why a manufacturer would care.

[tawilson]

I use up whatever chains I have going and start with new chains and sprocket.

[teakwood]

Bonus question I doubt anyone can answer... Why are spur sprockets still a thing? Rim sprockets are superior in about every way, no? They don't seem to add more cost in manufacturing, so why not use them on every saw? The only benefit I can see with a spur, is it enforces a clutch drum change. Might be better for some end users, but I don't know why a manufacturer would care.

So we have to spend more $ to change it! 

[ladylake]

You have a 6 tooth sprocket on a Echo CS400, I don't think anyone make a 6 tooth rim sprocket.  Steve

[Mad Professor]

worn sprocket will miss match a new chain causing both wear.

best thing is to use several chains with the same sprocket as they all wear

do I do it, nope, except on my mill.

if they made a rim for a 6 tooth the clutch bearing would be so tiny it would fail

[Al_Smith]

Depends on what brand of saw you are talking about .Some older Stihls for example with the oil pumps driven from the clutch drum it takes a different driving adapter depending if it's rim sprocket,spur drum or replaceable spur drum  .If you change tooth count on the spurs you have to use the right adapter because they aren't one size fits all .
On like trim saws,classic being the 020-200 T they have in 3/8" pico a 6 and a 7 tooth spur .Standard of course being 6 tooth .A 7 will really scoot if you have enough power to run it .One of mine  has a little "enhancement " and it does 
IMO for the average person it really is not an advantage to up the tooth count . .At the end of the day you won't see a difference .Perhaps production cutters would see a difference ,can't really say .