crzybowhntr
ArboristSite Operative
you have more money in bars than I do chainsaws!! Nice vids..
36" Bar comparison
- Thread starter redbull660
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redbull660
Addicted to ArboristSite
Well I guess I like to think of it like a transmission...
1st gear in any transmission has most torque yes? it's smallest yes? smaller sprocket = more torque.
5th gear in transmission has less torque and more speed yes? it's much larger than 1st?
wide sprocket tip on chainsaw bar = larger sprocket yes? = more speed less torque.
BradSt
ArboristSite Operative
The tip sprocket isn't transmitting any power though. You can't use the bicycle sprocket system in comparison this way. Now if you had a wheel attached to the axle of the front sprocket, and were driving something with it, then the diameter would matter. In the case of a chainsaw, you're not, so it doesn't matter.
The only sprocket that determines chain speed and torque is the drive sprocket. You could have a 10" diameter nose on the bar, and the chain speed would be the same (taking friction/parasitic losses out of the equation).
Think of a hard nosed bar...no front sprocket...Chain still runs the same, albeit a bit more friction.
redbull660
Addicted to ArboristSite
So when you drop the bar into a cut and the chain that is pulling back towards the saw is doing the cutting/pulling chips/cuts outta the wood...the size of the sprocket/nose has no effect?
As far as real world goes... Here is what I've tested:
wide cannon vs narrow cannon 28" -
1. wide cannon was faster in cookie cuts every time. Not by much...1-2secs in a 30-40sec long cut. But it was always faster, every head to head I did with them.
2. narrow cannon I could lean on it more. It had more torque for sure.
I loved that cannon wide nose...very expensive hard bar to get. So believe me I did a lot of small comparisons between the two. And I ended up selling the wide nose because I like torque.
Stihl 30" wide vs 30" narrow
1. again the wide was always faster. I didn't do many tests but the wide was always faster.
2. the narrow had more torque. You could lean on it more.
Stihl 36" wide vs 36" narrow
same thing.
pics of the bars if you don't believe me. http://www.arboristsite.com/community/threads/bar-data-picture-thread.265892/
As far as real world goes... Here is what I've tested:
wide cannon vs narrow cannon 28" -
1. wide cannon was faster in cookie cuts every time. Not by much...1-2secs in a 30-40sec long cut. But it was always faster, every head to head I did with them.
2. narrow cannon I could lean on it more. It had more torque for sure.
I loved that cannon wide nose...very expensive hard bar to get. So believe me I did a lot of small comparisons between the two. And I ended up selling the wide nose because I like torque.
Stihl 30" wide vs 30" narrow
1. again the wide was always faster. I didn't do many tests but the wide was always faster.
2. the narrow had more torque. You could lean on it more.
Stihl 36" wide vs 36" narrow
same thing.
pics of the bars if you don't believe me. http://www.arboristsite.com/community/threads/bar-data-picture-thread.265892/
BradSt
ArboristSite Operative
Even with the chain cutting and heavily loaded, the diameter of the tip/bar sprocket isn't part of any "gearing" equation. There may be slight differences in inertia and friction, but those differences should be negligible. The larger tip/bar sprocket will turn at a slower speed, so that should cut friction in the bearings, but it is a tiny bit heavier, so there is more mass to accelerate.
Theoretical "free" chain speed is dictated by engine RPM and drive sprocket diameter. That is all. Like I said earlier, the bar sprocket is just along for the ride. Madsen's website even has the formula to calculate this. The only inputs are chain pitch, sprocket teeth, and engine RPM.
Not that I don't believe your results, it just has to be another unaccounted for factor. I can't explain why the narrow bars allowed you to lean on them more. It just doesn't make sense to me. The problem is, it is tough to quantify "leaning on it more". You can't measure those forces easily.
This was a very interesting test though, with some surprising results. Those Stihl bars got hot!
redbull660
Addicted to ArboristSite
"The larger tip/bar sprocket will turn at a slower speed"
yet every wide nose bar I had was faster than the narrow?
We need a physics dude to explain this out. I mean no dis respect. But you've got explanations that sound pretty good. And I've got measured results which completely disagree.
yet every wide nose bar I had was faster than the narrow?
We need a physics dude to explain this out. I mean no dis respect. But you've got explanations that sound pretty good. And I've got measured results which completely disagree.
BradSt
ArboristSite Operative
Haha, I went to college for mechanical engineering, but I'm technically not a physics major. You don't know me from Adam, so I don't expect you to just take my word.
Yes, the bar sprocket turns slower (not the chain), because the circumference is larger. Just like larger wheels/tires on your car turn slower than smaller ones. The 13T large nose sprocket turns 18% slower than an 11T one, for any given chain speed.
Try looking at it this way...On a tank or bulldozer, the track speed is not affected by the idler wheels or front axle wheel. It is only the drive sprocket and engine/transmission speeds. The bar sprocket on a chainsaw is essentially an "idler wheel".
The bar tip sprocket has no effect whatsoever on gearing.
Roller tip or solid effects the friction though.
Think of the front tires on a RWD car. Bigger ones will turn slower, but have no affect on the gearing of the car. Only the rear tire size affects it.
redbull660
Addicted to ArboristSite
I would think...
wide tip - would allow the chain to go around the tip easier = faster cuts.
narrow tip - would be harder to get around and thus would be pulled back harder to the rim sprocket/starting point = more torque.
how you explain that in scientific terms I don't know. I'm a finance guy. lol But real world tests... Narrow nose = more torque, lean on it more before it bogs down. Wide tip more speed faster times.
all this crap aside. If someone makes a wide tip light bar I'd be the first to buy it! lol
wide tip - would allow the chain to go around the tip easier = faster cuts.
narrow tip - would be harder to get around and thus would be pulled back harder to the rim sprocket/starting point = more torque.
how you explain that in scientific terms I don't know. I'm a finance guy. lol But real world tests... Narrow nose = more torque, lean on it more before it bogs down. Wide tip more speed faster times.
all this crap aside. If someone makes a wide tip light bar I'd be the first to buy it! lol
Wide tips v narrow will kickback more on contact.
redbull660
Addicted to ArboristSite
actually did this test back in april and forgot about it. Outside temp is probably around 30-40 degrees.
36" tsumura light vs cannon
I believe the main bar temps being higher on the tsumura are due to the clear coat finish. I've experimented with taking the finish off the tsumura and the temps on the mid bar drop in half. Just like where the yellow/orange writing is on the cannon the temp is higher. Not taking anything away from either of these bars. They are the cream of the crop compared to others.
36" tsumura light vs cannon
I believe the main bar temps being higher on the tsumura are due to the clear coat finish. I've experimented with taking the finish off the tsumura and the temps on the mid bar drop in half. Just like where the yellow/orange writing is on the cannon the temp is higher. Not taking anything away from either of these bars. They are the cream of the crop compared to others.
KenJax Tree
Terraphobic
Are the Total Super bars made from the same steel as the Light and Tough bars?
redbull660
Addicted to ArboristSite
as far as I know yes. I did a 28" comparison as well... http://www.arboristsite.com/communi...-cannon-tsumura-sugihara.276432/#post-5282641
In that comparison the total super bar did run a little warmer, but not by much. So I'd say the staggered cut outs of the light bar dissipate heat...probably the most efficient design of the light bars ...my guess anyway.
KenJax Tree
Terraphobic
Im more interested in the weight difference between 20" 3/8 Total, Tsumura light and tough, and Sugi LW
redbull660
Addicted to ArboristSite
based on what I've got. Seems you'd most likely save about 10oz 3/4 of a lb with either sugi or tsumura as they both weigh the same...most likely total super 20" weighs same as the other regular weight bars. Does it make a difference? Night and day if you ask me on something like a MS361 size saw.
KenJax Tree
Terraphobic
Its my 2260based on what I've got. Seems you'd most likely save about 10oz 3/4 of a lb with either sugi or tsumura as they both weigh the same...most likely total super 20" weighs same as the other regular weight bars. Does it make a difference? Night and day if you ask me on something like a MS361 size saw.
