Rim or Chain Sprocket, which?

Sorry if this is a duh question. I searched and didn't find much about the topic. I've got Stihl 021 that I'm running and after getting it all fixed up to go and reading alot of info on here, I think my chain sprocket needs replacement. It looks pretty worn so probably best to replace it. As I was looking at the IPL to get the part number for the replacement, I noticed I had the option of a RIM sprocket. So I can go either way. I have RIM sprocket that came on my new MS361, so I'm guessing the RIM is the "new" way to go, but I don't know the difference. Why would you choose one or the other? Any advantages or disadvantages with either, or just stick with what the saw came with which is a chain sprocket? Is there a significant cost difference to either? Thanks guys.

Rims have been around for a long time... they let the chain "float" on the clutch. If it has the option for a rim sprocket... I would do it in a heartbeat.

Rims are cheaper to replace than a spur sprocket too. Since all you replace is the rim.

Gary

A rim setup cost a tad more initially, but the rims a cheap, so you will save money in the long run - provided you use the saw some more than a few times a year, and need another new one - then you just have to change the rim, and they are cheap.

The rims also work a tad better than the spurs, as they can float a bit latterally (lines up better with the bar) - but again nothing to worry about, if you use the saw just a few times a year.......

Gary beat me to it, he is right!......:censored:



....I typed too slow, or too much, or both.......

Good info GAS and Troll. Thanks to you both. I think I will go with a rim setup on the little ol' 021 that's always been good to me...

SawTroll said:

The rims also work a tad better than the spurs, as they can float a bit latterally (lines up better with the bar) - but again nothing to worry about, if you use the saw just a few times a year.......

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I don't understand how a chain can not line up with the bar on a spur sprocket the same as a rim sprocket. There is nothing to hold the chain in any configuration other than lined up with the bar with either setup.

WRW said:

I don't understand how a chain can not line up with the bar on a spur sprocket the same as a rim sprocket. There is nothing to hold the chain in any configuration other than lined up with the bar with either setup.

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Maybe! until that spur sprocket wears a bit then it makes groves to hold the drive links.
IMO the chain aint going to want to move about or it will get tighter.

WRW said:

I don't understand how a chain can not line up with the bar on a spur sprocket the same as a rim sprocket. There is nothing to hold the chain in any configuration other than lined up with the bar with either setup.

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Your problem, not mine.....

scotclayshooter said:

Maybe! until that spur sprocket wears a bit then it makes groves to hold the drive links.
IMO the chain aint going to want to move about or it will get tighter.

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OK, LOL. Now, how does the groove in the sprocket become misaligned with the bar?

Loose sloppy chains...

You would be suprised at how bad some spur sprockets get worn out "misaligned".

Gary

WRW said:

OK, LOL. Now, how does the groove in the sprocket become misaligned with the bar?

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How about when you change bars or get a bit of dirt behind the bar or even flip the bar
spurs are ok until they wear out then i change mine for rims
seems to be better wearing metal in a rim

GASoline71 said:

Loose sloppy chains...

You would be suprised at how bad some spur sprockets get worn out "misaligned".

Gary

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OK, but previously it was stated that the groove wouldn't let the chain move. I'd like to see an example of what you're describing. It sounds more like the bar was misaligned to the sprocket as I understand it now.

scotclayshooter said:

How about when you change bars or get a bit of dirt behind the bar or even flip the bar
spurs are ok until they wear out then i change mine for rims
seems to be better wearing metal in a rim

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The bars are pretty uniform side to side and even bar to bar (within one manufacturer). Enough dirt behind the bar to effect what you describe would, in my opinion, allow oil to leak out without entering the oiler hole. I could be wrong, I haven't seen it all yet.

That's not to say that rims are not a better deal on a saw that's going to get a fair amount of use.

WRW said:

....

That's not to say that rims are not a better deal on a saw that's going to get a fair amount of use.

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That is just about what I said, wasn't it......

SawTroll said:

That is just about what I said, wasn't it......

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I never said it wasn't just about what you said.

Rims are better!
easy cheap change from 7s to 8s 325 to 3/8 etc
You cant argue with that lol

Rims are a lot better when you throw a chain as well. They don't have the tendency to chew up the drive links like a spur does when you throw a chain.

scotclayshooter said:

Rims are better!
easy cheap change from 7s to 8s 325 to 3/8 etc
You cant argue with that lol

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They fit in the pants pocket better, too.

Cerran said:

Rims are a lot better when you throw a chain as well. They don't have the tendency to chew up the drive links like a spur does when you throw a chain.

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I've heard that, but never experienced it. Knock on wood.

WRW said:

OK, but previously it was stated that the groove wouldn't let the chain move. I'd like to see an example of what you're describing. It sounds more like the bar was misaligned to the sprocket as I understand it now.

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Take a saw with a rim and start it and then flop it over so you can see the rim and clutch. Whether at idle or hittin' the throttle... trust me, you will see side to side movement. It might not be much but there will be movement. Now loosen the chain a tad and do the same thing... then watch it move.

Gary