Drive sprocket wear. How long should one last?

[Coralillo Lo Pro]

Some people wait until they look like the one in Post #3, by @Mad Professor.

At that point, a user could experience erratic chain tension, performance, etc.

Philbert

Mine on the 880 was about like that shortly before exploding completely.

 

[Joseph Acquisto]

What kind of lube for the caged needle bearing? High temp brake or wheel bearing grease good?

 

[Philbert]

What kind of lube for the caged needle bearing? High temp brake or wheel bearing grease good?

I use white lithium grease.

STIHL used to sell it in small, convenient toothpaste like tubes.

A lot of guys, who grease their guide bar nose sprockets, use the same grease for both.

Philbert

 

[HumBurner]

Pretty sure it is a spur (a.k.a. "chain sprocket"?). From what I recall when chainging chains, it is a one piece "drum and drive", with a fairly "wide" surface for chain drive. Like the drive "spur" or gear was brazed onto the drum. Guess I need to go take it apart to be sure.

The sprocket is a lot cheaper than the drum but the kit to change over is about what the spur costs.

Other than the part cost, why do you recommend changing?

In my experience, chains ride better on a rim than the spur. The rim can slide a hair on the clutch, but it retains the chain. When the chain slides much more than a hair on the spur, it can derail. I found spurs to lead to more chain tossing in brushy/limbing conditions, as well as more damage to both the tangs on the chain and the lobes of the spur sprocket.

 

[woojr]

I always treated the bar chain and sprocket as a unit in which all needed to work at a level that meant I was cutting effectively each time the chain rotated one time around the bar. That maintenance was important. Always start with a clean bar with a sharp chain adjusted not too tight but spun smoothly by hand. That when revved it spun some oil off the end of the bar. As soon as I could feel the saw wasn't cutting near perfect I stopped and ran a file on it. I'd check for chips in the bar groove and see that it was oiling well. As far as the sprocket wear, I'd check the bearings and clean and lube. I found sprockets lasted longer if the chain and bar are kept in tip top shape. The time it took for cleaning and sharpening was time worth spent. Cutting with a less than sharp chain ruins the other parts. If a worn chain and sprocket are overtightened you can feel the thump, thump, thump of each chain drive link engaging the sprocket. I viewed that as a hammer tapping on the main bearings each revolution. Watch Buckin Billy Ray Smith on Youtube for saw maintenance tips. He gets those chain teeth about as short as they get and still cutting good. He has a good show on bars as well. You should be able to see those pretty chips and not pushing and wiggling the bar around. And oil spitting off the end. Maintenance is fun and cost effective.