so whats the deal with skip chain?

[jokers]

Not dissagreeing with anyone here, but your post brings up a point worth considering, Russ. You mention that racers fun full comp., and therefore this means that full comp. is more efficient. That is obviously true when running high horsepower saws, but does that directly relate to the average joe running an 036 with a 24" bar?

Well the average guy running a 24" bar on an 036 is intellectually challenged in my opinion, and my opinion is based on both actual experience with this model and Stihl`s recommendation of a maximum bar length of 20" on this model. I don`t consider Jeff to be the average joe, he typically seems a bit brighter.

Afterall, a semi truck hauling 40,000 lbs., is running more efficeintly per pound than a pickup truck hauling, 5,000 lbs., but this doesn't correlate to saying a pickup truck will haul 40,000 lbs. more efficiently than 5,000.

You`re right to an extent Rex, there is no corollary suggesting that a pickup will haul 40k#s more efficiently than it will haul 5k#s because infact, it may not haul 40k#s. Let`s consider something else that you spoke of with authority, but apparently have little knowledge of. The average over the road tractor weighs 26k# and the average 40' flat trailer weighs 13k# for an average total weight of 39k# so how does this rig hauling 40k compare to a 5,000# pickup hauling 5k#? Pretty similar efficiency, no?

The economy of the scale of the larger truck does however allow the larger truck to be built with heavier components and a better power transmission system more suited to this sort of daily service.

So, we obviously need to take power output into consideration when speaking of efficiency, no?

No, efficiency is efficiency, as in a coefficient. Performance is a different subject and is more accurately what we are talking about here. If it is not, why don`t we all revert to bucksaws or axes. These tools will just as efficiently fell a tree as a chainsaw, if the measure of efficiency is considered to be the ability to perform the job such as implied by your corrolary.

But, you do touch on this when you say full skip on a short bar is a "crutch" for an underpowered saw. Well, if a guy likes running an 036, then saying that full comp is a crutch for low power is just the same as saying he needs a bigger saw--something he's not arguing. For his 036 application, seems full skip is working fine for him.

Yes and no. Jeff implies that skip chain gives him the best performance on any bar length and powerhead combo. I disagree. Skip chain allows him to use an underpowered saw head for a job that it was not intended for in much the same way that low range on the transfer case of a 4wd truck would allow him to pull a 40,000# load. Yeah, it can be done. Is it the best sense to do it this way? You tell me.

BTW, the cornerstone of Jeff`s argument is this,

And the whole premise of chainsaws being chainspeed, it's better, (better as in more efficient and effective) to have fewer teeth cutting at full speed than to have more teeth cutting slower, or bogging the saw down completely.

He`s making some awfully large assumptions that a full comp chain when properly applied is going to pull the saw below it`s peak power output rpm range any more so than skip chain. This isn`t necessarily true in the real world and given the much higher efficiency of cutting chips per revolution or sf/m of a full comp chain vs a skip chain, you`d have to go quite a ways below the peak hp range of the powerhead before realizing an advantage for the skip chain. So far below that it would be considered lugging and abusing the saw.

Russ

 

[Marky Mark]

Russ since I am the AS Historian I hope you don't mind me stepping in here.Here's a few debates we had over the years here.

1

More teeth on a chain means smoother and faster cutting, period.
Art Martin

Of course Tundra Otto gace his wonderful post in this one I miss him.
2

 

[spacemule]

Wow Russ. You must have too much time on your hands.

When I spoke of efficiency between a semi and a pickup, I was speaking of fuel efficiency. An 80,000 gross weight semi will average between 6 and 7 mpg. Take a diesel pickup with a 10,000 gross weight and it will only average 15-17 mpg. I'd say that's quite a difference, but as I noted earlier, efficiency and power output are interrelated because the pickup is not large enough to take advantage of economy of scale, and will therefore always require more energy imput per lb. I think we're saying the same thing here, no?

 

[jokers]

Wow Russ. You must have too much time on your hands.

Why would you say that Rex, because I tried to offer a point by point argument to your assertions? Isn`t that how topics are technically analyzed?

When I spoke of efficiency between a semi and a pickup, I was speaking of fuel efficiency.

Since noone, including yourself, had previously mentioned fuel economy, and considering these quotes from earlier in this thread;

....Yes, it does not cut quite as fast as full house....

Cutting with a full sequence chain is faster and easier, duh!

I believe the issue with a longer bar is the chips have no where to go, and hence interfere with the chain remaining in contact with the wood. This only occurs on longer bars.

And the whole premise of chainsaws being chainspeed, it's better, (better as in more efficient and effective) to have fewer teeth cutting at full speed than to have more teeth cutting slower, or bogging the saw down completely.

I`ve had no trouble comprehending this thread to be a discussion of cutting efficiency, or as I`d rather call it, cutting performance.

Food for thought. Full comp chain has half as many cutters as drive links per loop. Skip chain has 1/3 as many cutters as drive links per loop. Look at this info in the context of a typical 72dl 20" chain, the full comp has 36 cutters and the skip has 24. Even the simplist, most basic math shows that skip has only a 67% potential cutting efficiency when compared to full comp when both are spun at the same speed. Given that most stock saws have a range of several hundred rpm at peak or near peak power, a saw would have to be severely underpowered for the task or pushed way too hard for the engine to be not running at near maximum in the cut rpm.

Of course there are variables affecting cutting efficiency/performance with chip clearance being one of the most significant in comparably sharp and maintained chains. I honestly am not aware of anyone having chip clearance issues when running a 20" bar in any species of wood on a 60cc saw, are you? If there is an issue with the performance of a 60cc saw outfitted with a 20" bar, more than likely it is related to poor chain maintenance or operator skill, not bogging of the engine due to too many cutters slowing the engine down. This is of course my empericaly data based opinion, you are welcome to try and convince me otherwise.

Your statement regarding the efficiency of the semi vs the pickup, each moving it`s respective maximum payload could be discussed further, I don`t fully agree with the details although we do seem to be in agreement on the general premise. It is worth noting that a pickup rarely lasts more than two or three hundred thousand miles, often hauling empty in one direction, as compared to OTR tractors and trailers which routinely log 500,000 to 1,000,000 miles in their lifetimes, probably most often while hauling a max payload.

The discussion comes back to having the right tool for the job although ultimately it is a matter of "to each their own".

Russ

 

[spacemule]

I was just giving you a hard time, Russ. I think you're the new Glens on the forum. I mean that as a compliment.

I agree that 24" is too much for an 036, but then again I run a 20" on a 394, so what do I know? Yes, I did miss that Jeff was arguing skip is better than full in all applications, but I'm still unconvinced about which would be better in the small saw/big bar application. And you're right, I'm just discussing theory here without much practical application.

Of course there are variables affecting cutting efficiency/performance with chip clearance being one of the most significant in comparably sharp and maintained chains. I honestly am not aware of anyone having chip clearance issues when running a 20" bar in any species of wood on a 60cc saw, are you?

Yes, chip clearance will certainly be the largest variable, but on a saw with a smaller power margin, the others will be significantly more important.

Say we have a cut that requires 4 hp to pull through the cut efficiently, and we have two saws--one with 4.1 hp and one with 5 hp. Now, the factors other than chip clearance may only be a small percentage, but not having chip clearance problems won't change their importance. Say the other factors acount for .01 hp. Well, on the 4.1 hp saw, you've just used 10% of your power margin with that small amount, wheras on the 5 hp saw you've only used 1%.

This may be a bit of red herring, but I'm trying to show that other small factors become increasingly more important on a marginally powered saw, so eliminating the largest cutting problem doesn't lessen the importance of the others, as you allude to but don't fully address. Again, I don't think any of us are saying he doesn't need a larger saw, what I thought we were discussing is the most efficient setup for the 036/24" bar application--at least that's what I was addressing.

This is one of the more interesting threads we've had around here for a while.

 

[fishhuntcutwood]

As much as I want to bow out of this thread, and let the experts be the experts, I still need to clarify, so as to not appear to be randomly making stuff up and talking out of my a$$. I never said full skip is better in "all" applications. I mentioned my "short" 20" bar to illustrate that I don't even own a bar as short as many guy's long or medium bar. I hardly ever run the thing. I said that the benefits of skip are on long bars buried in wood-

I use full skip exclusively on all of my saws, and the shortest bar I own is 20". The benefits include the chip clearance on a long bar buried in wood, and it also gives you fewer teeth in the cut to eat up hp and slow the saw.....

I'll take everyone's word that full comp is king of the hill and that my 361 is supposed to run no longer than a 16" bar, and that I'm crazy for running anything otherwise, even though it works fine, and always has for me (and many others) in real world timber applications. But the original poster of this thread asked about full skip, and I gave him my opinion on why I like it.

And Russ, you mentioned earlier that regional preferences will dictate what folks run, and that's true. I was just in Michigan and walked into a Stihl dealer to see what they had, and I was more than a bit surprised to see that they didn't sell the 660 with anything longer than a 20" bar, unless you special ordered it! I guess this past weekend when I easily milled maple with a 660 and a 32" bar that would appear as crazy to them as my two foot long 361 job.

Alright, I'm done defending myself for this round, and still maintain that I'm not trying to go point/counter point with any of you racers/experts/old hats. I wouldn't dream of it. Y'all have forgotten more than I'll ever know. I'm just backing up what I'm saying with what I've seen, and how things work for me.....just a regular guy with a saw cutting down trees who's never raced or timed a cut. :angel:

Jeff

 

[fishhuntcutwood]

I agree that 24" is too much for an 036...Again, I don't think any of us are saying he doesn't need a larger saw, what I thought we were discussing is the most efficient setup for the 036/24" bar application--at least that's what I was addressing.

This is one of the more interesting threads we've had around here for a while.

I do have larger saws-the 361 is my smallest. But I run 24"-32" bars on those, which I'd guess most would say are as much too long for the 44/46/56 as the 24" is for the 361, though none of those set-ups has let me down either.

And I agree that this is a good thread, and I applaud you guys, my co-posters for keeping things civil and not getting nasty or letting egos run wild. Thanks.

Jeff

 

[jokers]

Hi Jeff,

My rebuttals were not intended to denigrate you but unfortunately when topics are vigorously debated, it can easily appear that someone whom disagrees with you also thinks you are an idiot. This couldn`t be further from the truth and the fact of the matter is that I`m an idiot, just look at my "reputation".

I didn`t want to get into a discussion of regional practices because these practices aren`t always sound or perhaps there are extenuating circumstances, such as a saw is used primarily for cutting softwood without too much resin.

There are a multitude of possible reasons why a longer than normal bar could be best for a given set of circumstances. I often use a 20" bar on 3 cube saws like the 026 or 346xp for better reach, but rarely use the whole bar in a cut. For the average guy cutting firewood, this would be way wrong and the saw would be underpowered for what they might try.

This discussion is in reality a very gray area, because what constitutes a long bar is subject to site specific conditions.

Later, Russ

 

[average joe]

I was speaking of fuel efficiency.

So a semi getting 6-7 MPG and moving 40K is less efficiant than a pickup getting 15-17 and only moving 10k?

 

[fishhuntcutwood]

Hi Jeff,

My rebuttals were not intended to denigrate you but unfortunately when topics are vigorously debated, it can easily appear that someone whom disagrees with you also thinks you are an idiot. This couldn`t be further from the truth and the fact of the matter is that I`m an idiot, just look at my "reputation".

Worry not Russ! I've not felt slanted or denigrated at all. And I appreciate the fact that this is the internet and when communication takes place in purely verbal means, there's alot left to be desired when it comes expressing inflection and emotion, especiall like you say when these topics are vigorously debated.

All of my rebuttals have been intended to explain where I'm coming from, and why I think what I think, so as to hopefully illustrate that my opinions originate from local practices, regional applications based on terrain and cutting environment, how saws are used out here, and finally what I've seen my saws handle with me cutting with them. Am I'm probably too easy on my saws, compared to how many full time pros and racers treat and run their saws. Which may be why my saws cut so well for me-you can put a 24" bar on a Wild thing, and if you take it slow enough with a sharp chain, it'll cut for you! It's my perception of how the saw should run, and I don't know any better.

Which is why I've also stressed that I've not raced saws or even gone head to head with other saws. I know how they work in standing trees in a clearcut, but haven't a clue how they'd work in a race. I'm just a guy in the woods with a saw in his hand, you guys are in the know and have the empirical data and experience to back you up, which you share on here with us. I'm using my data, which is "I just cut down this tree and the saw worked as far as I know it's supposed to."

So keep up the sharing of info, and bear with us guys who are out in a stand of timber with a bar too big, a saw too slow and don't know any better.

Later Russ.
Jeff

 

[spacemule]

So a semi getting 6-7 MPG and moving 40K is less efficiant than a pickup getting 15-17 and only moving 10k?

Read again. I was saying exactly the opposite.

 

[jokers]

I was just giving you a hard time, Russ. I think you're the new Glens on the forum.

DID YOU CALL ME GLANS?!!!!

Actually I was doing this stuff here way before Glen showed up.

Russ

 

[spacemule]

For those on the sideline, TreeCo finds me annoying, and is a bit biased regarding anything I say. Right Dan?

 

[Gypo Logger]

For those on the sideline, TreeCo finds me annoying, and is a bit biased regarding anything I say. Right Dan?

Spacemule, the nice thing about Dan having you on ignore is that you can say anything you want about him without fear of retaliation.
Dan just has to assume then that what you are saying has no content whatsover and therefore Dan cannot be wrong with any response that he may make, however, your cover gets blown everytime someone quotes you.

Most of what Dan says anyway is just unsubstaniated poop when the truth is scutinized-- he doesn't mean to offend and is a good soul, but it is his objective to make everyone a legitimate target.
John

 

[spacemule]

Funny that Dan takes this attitude. Russ, whose virtues Dan extolled, told me I had a point, and I did say that the majority of my post was speculation--questions if you will. Like I said, there's some pretty heavy bias floating around in there. In fact, the last communication I got from Dan (he was still banned at the time) told me I was his hero (I'm not making that up--it was after I had been arguing with Netree on the forum and Dan was vexed at the moderators of this site) and he begged me to try to get him allowed back on this site. I didn't respond, and he's been biting at my heels ever since. That's all I'll say on the matter. Now, if no one quotes me, he won't read this. lol

 

[Marky Mark]

Funny that Dan takes this attitude. Russ, whose virtues Dan extolled, told me I had a point, and I did say that the majority of my post was speculation--questions if you will. Like I said, there's some pretty heavy bias floating around in there. In fact, the last communication I got from Dan (he was still banned at the time) told me I was his hero (I'm not making that up--it was after I had been arguing with Netree on the forum and Dan was vexed at the moderators of this site) and he begged me to try to get him allowed back on this site. I didn't respond, and he's been biting at my heels ever since. That's all I'll say on the matter. Now, if no one quotes me, he won't read this. lol

I just had to, one thing that is nice since several people got banned I have more room in my ignore area to add new members that I don't agree with. Dan I gave you some positive feedback for you reputation but I guess when your as hated as me there's nothing left to but smile smile smile.

 

[spacemule]

I knew someone would, thanks Marky. lol Folks either hate me or love me. I shouldn't have made that post--though sometimes things just get stuck in my craw. I really should be quiet more too, since I don't have much to add.

 

[Gypo Logger]

I knew someone would, thanks Marky. lol Folks either hate me or love me. I really should be quiet more too, since I don't have much to add.

Rex, I don't believe this to be the case. You are probably a nice person that has something to offer. It's just that some of us has had fun making a legitimate target out of treehosers after their recent attempt to infiltrate and overthrow AS. Were you not a treehoser you may get a different reception.
Anyway, enough of the political BS, lets get back on topic if only for a little while.
I have only used skip chain once for large pine on a husky 385 and found it really nice to use with a whole lot less filing as well.
Anyway, here's one from the archives.

John

 

[Marky Mark]

Gypo I was looking for a picture you posted some time ago.You were cutting some big trees and one landed on the fence. So this is the best I could do.

 

[Gypo Logger]

I was looking for that picture, but that one's better I think. lol
John