Does the # of Guide Bar Sprocket Teeth Matter?

[striderzz]

Here's what happened:

When I purchased my MS 460 I bought 25" Stihl bar to go with it. The label on the bar listed the MS 461 but NOT the MS 460. I ask the dealer about it and he said it didn't matter, it was a typo (my wording, not his). The shop was out of 28" bars, 32" I already had and 20" was too small. I decided to believe him and bought the bar.

Fast forward to now. I bought a new 25" chain from a different dealer the other day. When I opened the package a Stihl pamphlet fell out that I had never seen before that is titled "Bar and Chain Information". On it is a chart of bars that work with various saws and I noticed that the MS 460 had only (1) 25" bar listed with 10 teeth. The MS 461 had (2) 25" bars listed with 10 & 11 teeth respectively.

I counted the teeth on my bar and it is 11. So what does this mean? I understand what happens with the drive sprocket when you go from 7 pin to 8 pin (chain spins faster) but what happens when the bar sprocket teeth increase?

Thanks for educating the ignorant.

-n

 

[AKDoug]

The radius on the nose of the bar dictates how many teeth are needed for the nose sprocket. The 10 tooth nose would be a smaller radius than an 11 tooth. That's about all there is to it. The smaller diameter 10 tooth Stihl bar is considered a green dot low kickback bar. It's commonly found on the more consumer models like the MS311's.

 

[watsonr]

Bar sprockets are sized like clutch sprockets. They both need to match tooth size. Look on the bar and see what it say's. Doesn't matter how many teeth on the bar for the most part, just that it matches the sprocket for size. If the drive sprocket is .375 (3/8), then the bar needs to .375 (3/8). And the chain needs to match the gauge on the bar .050, .058 or .063. Any of the gauges will fit the drive sprocket.

460 or 461 should be the same.

So you want a drive sprocket that says 3/8 (.375)
you want a bar that says 3/8 .050 and 84 DL
and a chain that says 3/8 .050 84DL

everything is then matched. Both the bar and chain could also be .063 gauge, that's OK too. Most homeowner bars are smaller 10 tooth and the 3/8 are normally 11.

Hope this helps.

 

[striderzz]

The radius on the nose of the bar dictates how many teeth are needed for the nose sprocket. The 10 tooth nose would be a smaller radius than an 11 tooth.

So that is all? It doesn't make the chain a little tougher to pull around the bar nose or increase drag or something? I am just trying to wrap my head around it since it seems such small changes in configuration can make such a large impact on performance in chain saws and I have never heard anyone talk about bar nose sprocket teeth. And the fact that Stihl recommend differently for the 460/461 is the odd part.

Here is a pic of the pamphlet that shows the 11 tooth bar and the 10 tooth bar both offered for the 461, but only the 10 tooth offered for the 460. Seems really weird. And to increase confusion, my bar is a ES Bar, which according to the chart should be a yellow bar, right? But my bar is printed with Green Dots where it attaches to the powerhead. Seems inconsistent as well.

-n

 

[watsonr]

it also shows that the bar length is increased on the 11 tooth, meaning the belly of the bar is wider and there fore needs a larger sprocket to accommodate.

 

[longbowch]

I have a 25 inch bar on my 440 and the sprocket nose has 13 teeth. I think it is better for plunge cutting? The chains fit better and never run out of adjustment, but it is definetly heavier.

 

[Franny K]

I would guess it has to do with the rotational inertia of the saw/bar/chain assembly. Is the 461 heavier,lighter or weight distributed somewhat different front to back? A larger nose sprocket makes it harder to achieve the green low kick back rating. Notice how the shorter bars get 10 but the longer ones get 11. Bar length must effect the ability to achieve green status as well. You could put your question to stihl help in the form of an email often that is better than a fourm where anyone can answer you. Unless you run a green chain you don't get the green bar/chain rating.

 

[SawTroll]

10t nose bars often will be a bit lighter abd slimmer that the larger nose ones, and is mainly made for reducing the possibility of a kick- back (not needed if you know what you do, and are awake when cutting).

Other effects is that the bars either are slightly lighter - or in some cases the whole bar is slimmer, with more weight reduction. This can make the saw balance the bar better. :msp_smile:

The down side is that they don't bore cut as well as bars with wider tips and the same chain (but the difference doesn't bother me the least with 10t noses, as I am no professional).

 

[XSKIER]

I will say that the wide nose bars sure look a lot cooler. I don't think they do anything for sideways balance while in the cut though...

This is a wide tip 32" ES. I think it is a 13 tooth 3/8" .050, but it might be 11. For some reason I think my much slimmer sugihara is an 11 tooth.

Edit: sorry that pic is of my old .404 bar and chain. The 3/8 has the same profile.

 

[SawTroll]

I will say that the wide nose bars sure look a lot cooler. I don't think they do anything for sideways balance while in the cut though...

This is a wide tip 32" ES. I think it is a 13 tooth 3/8" .050, but it might be 11. For some reason I think my much slimmer sugihara is an 11 tooth.

Edit: sorry that pic is of my old .404 bar and chain. The 3/8 has the same profile.

The wide Stihl ES bars have 13t moses in 3/8".

 

[AKDoug]

So that is all? It doesn't make the chain a little tougher to pull around the bar nose or increase drag or something? I am just trying to wrap my head around it since it seems such small changes in configuration can make such a large impact on performance in chain saws and I have never heard anyone talk about bar nose sprocket teeth. And the fact that Stihl recommend differently for the 460/461 is the odd part.

Here is a pic of the pamphlet that shows the 11 tooth bar and the 10 tooth bar both offered for the 461, but only the 10 tooth offered for the 460. Seems really weird. And to increase confusion, my bar is a ES Bar, which according to the chart should be a yellow bar, right? But my bar is printed with Green Dots where it attaches to the powerhead. Seems inconsistent as well.

-n

That pamphlet is incomplete in regards to bar choices. You need to look into Stihl Chains, Bars and Accessories catalog for a more complete listing. Depending on the publishing date, things change. The 10 tooth 25" ES bar is a low kickback bar. It will run fine with yellow RS or RM chain.

BTW. There are a couple of typos in the 460/461 portion of the catalog also.

 

[jus2fat]

Green (safety) and Yellow (non-safety) Bars

I am confused about it and hope SawTroll or Watsonr or anybody can explain the difference.

I totally understand about the chains..but..am confused about the difference in the bars..??

I've never thought about it..just thought Stihl "E" bars were 'dotted' green and "ES" bars were 'dotted' yellow.

Soo..what's the deal..?? - I understand low kick-back chains with 'bumpers'..but what's with a low kick-back bar..??

In like..how does it work..?? - Just 'hype'..?? - Just something that I've never thought of - thanks in advance..!!
:cheers
J2F

 

[AKDoug]

I've got a few moments before the frost melts off the roof I am working on.

I am going to just address the 3/8 .050" bars. 25" is the only length that is weird.

ALL the Rollomatic E bars below 25" are green low kickback bars.
The 11 tooth Rollomatic E bar in 25" is a yellow dot bar, it likely failed the ANSI test and rather than not offer it they just labeled it yellow. I think it used to be green so there may be some old stock out there with green dots.
ALL the Rollomatic ES bars are yellow dot bars EXCEPT of the 10 tooth 3003 000 4030 bar. Not sure why they made it, but it's available.
The Rollomatic ES 25" bar is made in two models, a 10 tooth low kickback green dot bar and an 11 tooth yellow dot bar, both bars use an 84 driver chain.

There are no Rollomatic E bars over 25". All bars over 28" in ES and are yellow dot bars only.

The typos in the catalog are that they list a 72 driver chain for the green dot 25" ES bar in the chart in the 460/461 section . This is WRONG. They also called the MS461 a SM461 in the chart.

 

[AKDoug]

Now for the "low kickback" part. In order for the design of the low kickback chain to work it usually must be matched to a bar that works in conjunction with it. To achieve the "low kickback" rating there is a specific test. Stihl designs the chain and bar to pass the specific test. As the chain goes around the tip of the bar the "low kickback" bumps will limit the amount of bite the cutting teeth can get in that most dangerous kickback area (the upper last couple inches of the bar at the tip). To allow the bumps to work, a specific radius on the bar nose needs to be used.

The Stihl Chain, Bar and Accessories catalog part number is 0461 005 0000. The paper copies are not free to dealers, so expect to pay for a copy if you are interested.

 

[SawTroll]

I am confused about it and hope SawTroll or Watsonr or anybody can explain the difference.

I totally understand about the chains..but..am confused about the difference in the bars..??

I've never thought about it..just thought Stihl "E" bars were 'dotted' green and "ES" bars were 'dotted' yellow.

Soo..what's the deal..?? - I understand low kick-back chains with 'bumpers'..but what's with a low kick-back bar..??

In like..how does it work..?? - Just 'hype'..?? - Just something that I've never thought of - thanks in advance..!!
:cheers
J2F

It is the number of teeth in the nose that for all practical purposes deside if a bar is "green" or "yellow".

In reality, there is of course no sharp "breaking point", it is just a random choise, likely by "ANSI".

It doesn't bother me a bit if a bar is labelled yellow or green, as long as it does what I want it to. Unlike green chain, the fact that a bar is labelled green does not affect the cutting, as long as the green label is based on tip size, and not stupidities like "tip guards". Another thing I don't like is the use of small tips on otherwise normal width RSN bars, for obvious reasons....

 

[Eddy_t]

It's simple, fatter nose = larger kick back zone = yellow dot
The nose has to be fatter to accommodate the extra drive link, so the kickback zone is enlarged, think of a clock, the zone is 11 to 4

 

[striderzz]

Just thought I would share the official response I got back from Stihl US.

Hello Nick.
I will be happy you answer your concerns. The number of teeth in the sprocket of the bar do not affect your cutting performance at all. The green label, reduced kickback bars have a narrower nose on them and the sprocket only contains 10 teeth. The yellow label, non-reduced kickback bars have a wider nose on them and the sprocket contains 11 teeth. These two different bars are interchangeable also.
I hope this helps.
Mark

 

[sawfun9]

The wider nose is for doing a lot of plunge cutting. Some of the bars also have 13 teeth on the sprocket. Also for some to note, the bars used on the 201 have more teeth and wider nose than the ones used on the 192.

 

[treeslayer2003]

I tried to explain the difference to my DEALER, he just cannot get it. I buy the wide everytime if I can get it. OP, you will like the wide better if ya give it a try, less chance of chain jumping off while limbing.

 

[AKDoug]

The wider nose is for doing a lot of plunge cutting. Some of the bars also have 13 teeth on the sprocket. Also for some to note, the bars used on the 201 have more teeth and wider nose than the ones used on the 192.

That's because most 192's are shipped with mini-picco(.043 gauge) vs. the 201's picco (.050" gauge).. The 192 can take the same bars as the 201 if you want to, just make sure you have the right sized chain.