rim vs spur

[buck futter]

I understand the rim is cheaper and easier to replace are ther any other advantages?

Lucky

 

[Diesel JD]

I don't know, I like it on my 025. I think I remember reading that a rim causes less wear on your chain's drive links. Good thread, I was wondering pros and cons too on whether to go ahead and convert my 390 or wait till it really needs a new sprocket.
J.D.

 

[fishhuntcutwood]

It seems to me that it'd let the chain float laterally better than a spur would.

Jeff

 

[SawTroll]

I don't know, I like it on my 025. I think I remember reading that a rim causes less wear on your chain's drive links. Good thread, I was wondering pros and cons too on whether to go ahead and convert my 390 or wait till it really needs a new sprocket.
J.D.

It will, but I would have waited till a new sprocket is needed, or you are buying new chains. It is not critical, but the rim will make the whole system run smoother, causing less wear and tear.
As Jeff said, the system will be partly self adjusting.

 

[buck futter]

Wow you guys are fast, I didn't think anyone else was up this late

Lucky

 

[SawTroll]

It is morning here in Norway.

 

[pbtree]

Floating rims rock - they align perfectly, cause less wear on both the rim and on the chain, and are smoother to boot. I completely prefer them over a spur...

 

[WRW]

What is it about the spur sprocket that doesn't allow proper alignment?

 

[turnkey4099]

What is it about the spur sprocket that doesn't allow proper alignment?

The chain wears a "notch" in the spur and that's where the chain runs.

Harry K

 

[WRW]

My guess is that that notch remains in alignment with the bar groove. The notch is there because that is where the chain runs.

 

[Marco]

The spur setup has the advantage that any fumbly weekend warrior can change a chain and not have to worry about getting it in the ring so he doesn't tear his oiler up. Seen it happen on a 630 Johnsred. The same saw also had a hole in the oil tank from the pin getting drove through when he tightened the cover down without the bar hole in the right place. Some people can wreck an anvil.

 

[Marco]

It shouldn't be a problem with an out board sprocket though

 

[Diesel JD]

Wow...I can't believe anyone would ahve a hard time changing a chain on a rim sprocket, to me the spur is harder! I guess I will be oerdering that conversion kit from Bailey's ASAP. Why should I ruin my current chain with this setup?

 

[pinus]

I cant find at the moment proper link where rim versus spur was discussed
Anyways, rim is more proper, but more expensive system in production (drum-spline + rim).
Advantages:
1. chain will aligne better relative to the bar, so bar groove is less weared near the powerhead end.
2. Chain itself is less bended and flexed, so less weared.
3. Chain can be more loosen compared to spur system
4. If weared only the rim is needed to replace, not the all drum.
So, usually rim sprocet is named pro-system and spur sprocket as the one for occasional user

 

[WRW]

The rim sprocket has some advantages, but bar alignment is not one of them, nor is driver wear. The chain does not have to be adjusted tighter on the spur sprocket.

Cheaper and easier to replace do come to mind.
Also,in the event that the chain is thrown, the rim sprocket is less likely to continue pulling the chain and possibly damage said chain and saw. Maybe that is what you are thinking of?

 

[R Schra]

With a rim its easier to change 'gear' by using an other 6/7 or 8 rim. Or changing .325 chain/blade to 3/8....

wondering why?

fast rim for pruning out logs and small felling, slow gear for big logs, .325 for pruning with smoother surfaced cut, 3/8 for logging

 

[WRW]

R Schra,
That would be a definate advantage, though it takes away the excuse to buy more saws.

 

[pinus]

The rim sprocket has some advantages, but bar alignment is not one of them, nor is driver wear. The chain does not have to be adjusted tighter on the spur sprocket.

Cheaper and easier to replace do come to mind.
Also,in the event that the chain is thrown, the rim sprocket is less likely to continue pulling the chain and possibly damage said chain and saw. Maybe that is what you are thinking of?

That wasnt not not only my opinion, but confirmed by my experience

 

[WRW]

OK, tell me about your experiences. Keep in mind that tightening the chain moreso than you would with a rim might affect some of your findings.

 

[pinus]

The rim is supporting up to 20 and more m/s moving chain from both sides a littlebit. My MS270 from factory was with spur sprocket. The bars mounting end grooves are suffering from the chain vibrations and misalignements in so strongly that after some 30-40 tanks of fuel the bar walls were weared as the sharp "knives". With the spur I used it ca 70-80 tanks of fuel, now I use rim and all runs much smoother.
With the spur, during the limbing chain was whipped several times from bar. Now with the rim, and as was earlier with 026 too, that was never happen