can you change bar sizes on a chainsaw?

[iamquaker]

just out of curiosity can you change bar sizes on a chainsaw without damaging it?

currently i have a 16" bar. can you go up or down in size?


dont really have any plans of going bigger or smaller, but just could not sleep and was reading the boards this evening.

 

[Eric Johnson]

Yes, but you need a bar designed to fit on your saw. There are different designs for different saws, and the bar has to match the chain/sprocket configuration as well. Your best bet, if you want to do that, is take it to a dealerto be sure that everything matches up.

Obviously, you don't want to put a big bar on a small saw. But since most saws have longer bars than they really need, it's hard to go wrong with a shorter one. You'll get more power and it's easier to keep the chain out of the dirt and out of contact with various obstacles if your bar is shorter.

 

[computeruser]

Yes, but you need a bar designed to fit on your saw. There are different designs for different saws, and the bar has to match the chain/sprocket configuration as well. Your best bet, if you want to do that, is take it to a dealerto be sure that everything matches up.

Obviously, you don't want to put a big bar on a small saw. But since most saws have longer bars than they really need, it's hard to go wrong with a shorter one. You'll get more power and it's easier to keep the chain out of the dirt and in contact with various obstacles if your bar is shorter.

Well said!!

Generally something in the 3:1 to 4:1 ratio of engine displacement (in cc) to bar length (in inches) represents a good rule for where the saw will perform best. Exceptions exist, obviously, but this is a good rule to follow absent some compelling reason not to.

The remark about most saws having bars longer than they really need (or want for optimum performance) is very true, and is a uniquely American behavior. For whatever reason we seem to equate bar length with capability, when engine displacement and power output are what really matters. If you look at the bar sizes sold on particular powerheads in Europe rather than in the US, you'll find that VERY short bars are often paired with fairly powerful saws. For example, 13" and 15" bars are common on saws up to 60cc, where here even 35cc saws get slapped with 16" or 18" bars here in the US; not surprisingly, the performance of these saws suffers with their overly long bars. A while back I decided to try the whole "relatively big engine with a short bar" idea and have been VERY pleased. I think it makes the saws MUCH more productive, whether in firewood, felling, or limbing. You still have the ability to slap a longer bar on if needed for a particular task, but you don't have to carry it around all the time for those few instances where the extra length is actually needed.

Attached is a picture of a couple Husqvarnas that I set up this way - short bar relative to the saw's power. The 238se has a 13" bar and narrow kerf chain, and the 154 has a 16" bar. These powerheads were originally equipped with 16" and 20" bars, respectively. The improvement in performance and overall saw balance have been substantial. The improvement has been most noticeable on the little 238se, which went from being a small saw that seemed barely powerful enough to take a full bar bite and was really only suitable for limbing, to a machine that is very nimble, can take a full bite of anything, and best of all, is now a truly viable firewood saw.

 

[Eric Johnson]

Match a light, powerful saw like a 346xp up with a 13-inch bar and some .325 50-gauge chain, and you can really cut some wood.

 

[Mr_Super-Hunky]

Match a light, powerful saw like a 346xp up with a 13-inch bar and some .325 50-gauge chain, and you can really cut some wood.

Very true, and the 346xp is an incredible saw. The only other iteam to also consider as well is balance. I just purchased a Dolmar ps5100 (4hp saw that weighs only 11 lbs and cost me $369.00).

Anyway, even though I will be cutting mostly smaller diam wood, I ordered it with a 18'' bar as many have said that this is the best "balanced" bar for this saw. Every saw is different. Some due better with shorter bars, and some due better with a bit longer. It just depends on the balance of the saw. This is very important as an improperly balanced saw is more apt to *bite* you when you get lazy/tired; especially if it is nose heavy.

 

[Gooserider]

Taking the advice about the engine to bar size ratio in the posts above, I just replaced the somewhat fried 16" bar on my Poulan 2150 "Woodsman" chainsaw with a new 12" bar and chain, along with an update that retrofits a chain brake to the saw. This is a 36cc "homeowner grade" saw, and it really had trouble pulling the bar on anything close to a full length cut.

The change is a BIG improvement in the way the saw cuts, although I have found I slightly miss the extra 4" I gave up. However I think the difference is worth it, the saw is lighter and balances better, so it's easier to use for limbing and small stuff, and even when I'm going into a big log it now has no trouble keeping full throttle engine speed even with the bar fully burried in a log.

Another change I made was to go to a chain that was not billed as "anti-kickback" and has no "bumper links" just cutters and rakers. This also seems to help the cut, although the saw does tend to buck back at me a little more - nothing I have trouble controlling though.

Only downside is the saw seems to vibrate more - I finish a couple of tanks and my hands feel numb for a couple minutes, which didn't use to happen with the longer bar and "safety chain" that didn't let the saw run so fast.

I guess it's time to to push a bit harder for the GF to let me get a bigger saw for the large logs.

Gooserider