Bar Length and Power

[AmateurSawer]

Does bar length really make any difference so long as you aren't running a full length cut.
I'm not talking about running a 25" on a 50cc saw but can't see where there's any difference in running a 16" or 20" in 12 inch diameter wood. Almost seems like the chin would run cooler in some situations.
Am I missing something in my thoughts? Reason like longer bars is the reach they give you being tall cutting close to ground level.



'

 

[lohan808]

It would be more a preference for your cutting style. Not trying to argue the logic of other chainsaw operators. I am short so the length only comes into play for me on big wood or if I am noodling in the woodpile. Taller fellas will tell you stand up and buck, and there is some consideration of kickback speed on the bar. Good question.

 

[3000 FPS]

I have used a 20" bar on a 46cc engine because of the very reason you mentioned. The reach.
But I would never try and bury that bar in wood.

 

[user 122190]

As long as the saw is not struggling and is oiling the extra length, you should be fine. Keep that chain sharp and you'll be helping yourself and that saw.

 

[computeruser]

Depends on cutting style so long as we are talking bars within reasonable limits relative to powerhead.

 

[Jonny Quest]

The Jonny Quest rule of thumb on bar length: "Try to use the shortest bar for the job".

There are no "style points" for a big bar...unless you are trying to impress that special someone.

JQ

 

[Huskybill]

I used 16” bars on my husky 266se with a 3/8” 8t rim, a 60 dL .050” ga. I also used the older 240 Sg 325”/.050”/66 dL a 9 t rim. It wasn’t till cutting at the fairs(ha’s, ha’s) I discovered running the husky 2100 with the 404” .050”ga, 9t rim and 16” or 18” bar with the rakers at .040”. The fairs were weeks apart it was a pia changing the saw over for the woods then back for the fairs. I just took it in the woods. She’s a beast to cut with. I took it easy at first expecting kick backs but it never happened. The faster speed saw worked even better in the woods.
Before this both my 2101 Xp and 2100 cd wore 24” 404” bar setups.

Going back in the woods after time off my first day cutting was half a day cutting. Break the body slowly up to speed. The second day cut the whole day but slow. The third day I’m limbered up kicking butt that 2100 was smoking.

 

[Dennbb]

Does bar length really make any difference so long as you aren't running a full length cut.
I'm not talking about running a 25" on a 50cc saw but can't see where there's any difference in running a 16" or 20" in 12 inch diameter wood. Almost seems like the chin would run cooler in some situations.
Am I missing something in my thoughts? Reason like longer bars is the reach they give you being tall cutting close to ground level.



'

Very slight difference. Longer bars have a little more drag, but it's not really noticeable

 

[Valpen]

The longer the bar, the longer the chain, and higher number of cutting teeth in the chain.
Therefore, the more time the chain will cut before needing sharpening (in normal use).
The downside is that it requires more time to sharpen the extra links in the longer chain.

IMO the extra reach is worth a lot as I am tall and not as young as I used to be. As stated in other posts, as long as the saw is happy and not burdened, and the chain is getting enough oil, you should be able to run the maximum recommended bar length. If you have a short bar, you can easily find a situation where you wish it were longer. I don't think I have ever encountered a situation where I thought I needed a shorter bar.

 

[Maintenance supervisor]

Bow Bars were designed to stand and buck with , funny how everyone is trying to buck with a longer bar when there's a specific bar already created for this purpose. Strange?

 

[Evan]

Depends more on if you actually cut much wood, its fine if you dont since CAD does crazy things.

Im much more comfortable cutting with a 28" compared toba 50cc wirh a 18"
A super tall person might really prefer a longer bar.

 

[thenne1713]

Bow Bars were designed to stand and buck with , funny how everyone is trying to buck with a longer bar when there's a specific bar already created for this purpose. Strange?

UHhhhhhh, Bow Bars are no longer Manufactured/ no longer sold new, as they were found high risk/ Unsafe? Or am I crazy and wrong?

 

[Maintenance supervisor]

Pole barn and post fencing have gone out of style. Saftey hasn't really been an issue in the southern part of the country, AkA no OSHA ,thank God.

 

[Dennisthemenace]

For felling I reckon the shortest you can get away with. Bore in, 20" will drop near 3 ft, keep the speed up. Bucking, maybe a bit longer if required, limbing up heads and stuff on the ground I like a 28. Some old blokes like to stand up straight

 

[user 122190]

UHhhhhhh, Bow Bars are no longer Manufactured/ no longer sold new, as they were found high risk/ Unsafe? Or am I crazy and wrong?

They sure look unsafe.

 

[SuperDuty04]

They sure look unsafe.

View attachment 946161

There’s real okd yellow one of these sitting in my local saw shop. It’s always intrigued me.

 

[treeguy2020]

I bought my Stihl CM311 with a 18" bar i quickly changed it to a 16" bar, i mostly was limbing with this saw so why deal with more weight and more chain.

 

[KerfWatcher]

This is one of those misconceptions that gets over simplified by many a saw users and sellers.

-The chainsaw makes constant* power not dependent on the bar length, *for a given RPM.
-What cuts wood is the volume of wood (chips) being removed - volumetric flow rate.
-Volumetric flow rate of wood being removed is chip thickness at a speed (hence why people ask about RPM in the cut). Also why a smaller displacement saw can beat a larger displacement saw in smaller wood as TYPICALLY smaller saws will allow for a higher RPM.
-The more chain cutters in contact with the wood = more volumetric removal rate* (*for a given depth gauge setting). But also needs more power to keep removing material.

Linear chain speed "SFPM" (with no load) is a function of the drive sprocket diameter and does NOT change with bar length. However it is a gearing so going up in diameter, while it will increase chain speed, will decrease torque or pulling force on the chain.

Other factors
-Ability for the given saw to produce enough oil for the length of bar / chain (longer bars need more oil, especially in dryer wood)
-Friction between chain and bar that take power away from the cut (engine power - friction in the system = power to put into the cut to produce a volumetric removal rate). Can also cause a saw to rev slower due to friction and inertia of the chain.
-There are two different schools of thought on cutting speed. High chain speed with small chip load per pass, or lower chain speed with higher chip load per pass. Both can equate to the same volumetric removal rate, but are two different means of accomplishing that.

Soooo., In conclusion...a shorter bar will allow one to get the most "power" out of a saw as it will not be tempting to load it.

 

[Franny K]

-The more chain cutters in contact with the wood = more volumetric removal rate* (*for a given depth gauge setting). But also needs more power to keep removing material.

Should not this really be number of cutters passing a given point in some fashion instead of in contact?

 

[Abbeville TSI]

Bow Bars were designed to stand and buck with , funny how everyone is trying to buck with a longer bar when there's a specific bar already created for this purpose. Strange?

I remember bucking with an XL12 Super and a bow. A new bow blade is hard to find now, I wouldn't mind finding one for my 036 Pro.